Building a Communications Trailer from an Enclosed Cargo Trailer #2

It has been a couple of weeks since my last update so I figured I would give another update.  When we left off in the previous post I had just finished putting the first coat of Kilz on the walls.  The 2nd coat made things look so much better and then the gloss white coat topped it off.

One thing I forgot to mention in the previous post is I mounted an LED light that is pretty heavy above the side door.  I had to do that before I could close up the walls.  I had to add some additional support above the door because the aluminum shell could not handle the weight, at least not for very long.  Below is a picture of the light mounted above the door.

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Here is a picture that I took I think after all of the painting, you can see it turned out pretty good.

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It took a couple of days longer because I had to paint between the rain drops.  After I got the walls completed I put on the first layer of epoxy on the floor.  Sorry for the color but it was pretty dark out when I got the first coat on.

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The first coat went on a little thin and you could see the wood at some places.  The second coat covered those spots up nicely.  It took 3 days for the first coat to cure enough that you could walk on it without sticking.  On day 2 I went out to put on the 2nd coat and sat in the door on the side and stuck to the floor and could barely get up so I waited another day.

After the second coat of epoxy was on, I spread around some of the decorative metallic flakes on the ramp.  I had read that the epoxy can get slippery so I hoped that adding some texture would help with some traction.  I did not put any metallic flakes on the inside because I wanted to keep it smooth in case we use chairs that have wheels.

After 3 more days of the 2nd coat drying I added the clear protective coat.  This coat felt dry the next day.  However because of weather it actually had 3 days to cure before it got used.  Here are some pictures of the final paint and epoxy. 

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Next step was to get the ceiling and countertop materials so we took the trailer for a trip to lowes where we got the ceiling panels, the remaining countertops and some electrical components to start wiring up.

Most things in the trailer will work on 12 volts.  The plan is to have 6 12V AGM batteries that are charged either by solar or shore power.  Because I want to make sure that everything is safe and as highly compatible as possible with other power systems.  I decided to use a 50 amp 120/240 volt marine plug for shore power.  These are designed to be around water and you can find adapters to go to just about every other plug like generators, 30 amp twist locks, plugs used in RV parks and even down to the 110 volt 15 amp plug we are all used to seeing in our homes.

The plug I got is huge!  See the photo below.

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I installed the power plug on the left side of the trailer opposite of the door.  I was thinking that would be better than installing it on the door side because of foot traffic.  Also, since most of the electrical components are going to be installed in the nose of the trailer it would have to be behind the door which would interfere with the door holding latch.

Below are pictures of it installed on the side of the trailer.

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I have also been mounting equipment in the nose of the trailer and running electrical conduit.  I am trying to do everything up to building code even though it is not required in the trailer.  Everything is going to be grounded and safe.  Below is a picture of where things are with the mounting of components and running of conduit.

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As you can see by the photo there is still a long way to go but they are moving much faster than before.  Because just about everything uses 12 volts I decided to use 12 volt switch panels.  Below is the the big panel that will be by the door and control the lighting in the trailer.

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As you can see this switch panel also has a USB and 12V plug in addition to the battery charge status.  There are also 3 other switch panels at the different workstations.  They are to provide 12V and USB power in addition to control overhead work lights for that workstation.  Below is an image of the smaller panel.

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When I ordered these they called them 2 gang, 5 gang so I assumed they would fit into a 2 gang us electrical box.  Well that is not the case so I am going to have to make my own mounting solution for these panels.  These panels require a lot of room behind them for the wiring and the plugs are pretty deep as well.  I have not even attempted to figure out a solution for this yet, which is why you still see the 12 volt wires hanging out of the wall.

Things are starting to move much quicker than before but I only have the ability to work on things on evenings when there is nice weather and only up until dark.  My goal is to get it operational by Field Day which is only 11 days away.  In that time I have to complete the build and start installing and testing the radio gear and antennas.

I think I am going to start working on the ceiling because I am having to walk around it sitting on the floor and I also need to put it up before I can put up lights.  If I had lights, I could work longer at night.

I will post another update when I get some time, probably after field day.

Building a Communications Trailer from an Enclosed Cargo Trailer #1

I am going to create a few blog posts about my adventures in turning a cargo trailer into a communications trailer.

Why build a communication trailer?  Well there are a number of reasons.  The first one is to make transporting and setup easy for Ham Radio events like field day or when we do public service events like bike races, hikes, runs, etc.

I am also interested in emergency communications.  In building the communications trailer I am going to have it setup so it could be used in emergency situations quickly.  With the bad hurricanes last year and Hurricane Sandy in 2012 I want to be ready to help with emergency communications if needed.

So, I am going to document the process of building out the trailer in a few blog posts.  I purchased at 7'x16' from shore2shore trailers in Douglas GA.  We spent a few days in Hilton Head and went to Douglas GA on the way home to pick up the trailer to save the shipping costs.

Before doing anything I wanted to insulate the trailer.  I also want to paint the inside and do something to protect the floor.  I watched a ton of youtube videos about people taking these enclosed trailers and making them into campers.  I have found a few things on the internet where people have done something similar to what I am trying to do.

The first step was to go get supplies to insulate the trailer, paint it and then epoxy the floors.  Here is a picture of the supplies all loaded in the trailer:

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I still need 2 more counter tops.  I got the materials from Lowes and they were out of stock on the 2 6 ft countertops.  One thing I need to mention is about the lumber, I am going to build a wall in the back to create a storage area in the back of the trailer.  Also, the 3/4 in plywood I am going to place in the nose of the trailer to mount the battery charger, the solar charge controller, electrical boxes, etc.  The plywood that is on the walls in the trailer is pretty thin and I was concerned with the weight of the chargers it pull off the board.

So on to the first step, insulating the trailer.  I looked at different options.  Some suggested a spray on insulation and others just use the 4x8 pieces of foam.  After reading about the spray on insulation and the mess it creates as well as the fact that it is more than 3 times the cost of the foam panels.

Below are some pictures of the trailer with the walls mostly insulated.

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 You can see I ran some wires for the back.  One for power for the overhead light in the storage area and also the light on the back of the trailer (I will talk about the light in a little bit)

You can see I ran some wires for the back.  One for power for the overhead light in the storage area and also the light on the back of the trailer (I will talk about the light in a little bit)

The walls were more difficult that I expected.  It was not the wood that was hard but cutting the styrofoam that was difficult.  Using a knife did more ripping of the styrofoam than cutting.  I ended up buying a hot knife.  That made it easier but a hot knife is very slow.

One thing to notice is the gap between the plywood.  That may be normal for trailers but to me that seems odd.  Not sure if you notice but the gaps are not even so the wood was not hung strait.  The trim covers all of that up.

Next I insulated the ceiling, you will notice around the vent there are some small areas not insulated.  Those are where I am going to run the wires to power an Air Conditioner that will be mounted on the roof.  It became obvious throughout this process that AC might be a requirement.

I was doing this during some very hot and humid days.  The insulation helps to keep the trailer much cooler than it was originally.  When I was installing the insulation I could feel the heat from the walls, after the insulation that heat is gone.

Below are some pictures with the ceiling insulated:

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You will notice that above the door there is still a panel missing.  I am going to mount an LED flood light above the door but the light is pretty heavy so I need to properly mount it.  Here is the light I am going to mount above both the side and back doors:

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As of the writing of this blog post I still have not mounted the light.  You will see that later in the following pictures.

I used some spray foam to fill in some gaps, that is what the white stuff you see in different places.

Once all of the insulation is complete, I put the trim back up.  Because I saw how big the gaps were between the wood pieces, I decided to seal up the trim with caulk before painting.  Here is a picture with the trim up and caulked ready for painting.

 

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i have been working on this during days of mixed weather.  In between storms and rain, I got this far and tonight.  I went out between storms and put the first coat of Kilz2 on the walls.  It is going to take 2 coats.  From watching videos I learned that before you paint the walls you should use kilz as a primer and I see why now.  The wood soaks up the paint.  You can see in the picture of the first coat below that the wood just soaks up the kilz.  I did manage to get part of a 2nd coat of kilz on the walls before I ran out.  Below is the latest picture before I wrote this post.

 

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Keep an eye out for the next post with the next steps in the process.

D-star, DMR, Fusion, Which is right for you? Updated version

I created the first version of this post back in early 2016, it has been almost exactly 2 years.  Let me just say things have really changed since I wrote that initial blog post.  Not only has the technology changed / advanced, so have my personal preferences.  The blog post below is updated with all of the changes that have happened over the past 2 years.

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If you are an amateur radio operator and have not been living under a rock, then I am sure you have heard of one of the digital modes: D-Star, DMR or Fusion.  You may be wanting to dip your toes into the digital modes water but not sure which pool to dip them in.  This blog post is intended to present a fair unbiased opinion on each of the modes.  

Not until the end will you learn my preferred mode.  I use all of the modes I will discuss.  There are additional digital modes like P25, and Nexedge that I have not used and are also much less prevalent that I will not discuss.  I do not have enough knowledge of those modes to represent them.

Also, I want to make sure up front that this is not intended to bash any one mode.  I like all forms of technology and really do not like the people that are so biased toward one that every other mode is bad.  Each of these modes has a place and my goal is to help you decide which one fits you the best.

I am going to start off with a quick synopsis of each of the modes we are going to discuss then we will get into the comparison.

D-Star

Of the 3 modes we are going to discuss, D-Star is the oldest.  It was created by the Japan Amateur Radio League (JARL) and is an open standard.  It is important to note that is was created for Amateur Radio.  Most people relate Icom with D-star as they have been the primary manufacturer of D-Star equipment, however, they are just a manufacturer that has implemented this open standard into their products.  There are other manufactures that make add-on boards for D-star and Kenwood now makes a D-star handheld radio that is triband.  There is also a lot of other solutions for getting on D-Star that do not require a radio or local repeater.  We will discuss these later.

DMR 

Digital Mobile Radio is known as DMR and sometimes you will hear it referred to as MOTOTRBO.  MOTOTRBO is the motorola implementation of the DMR protocol.  DMR originated as a business communication standard in Europe.  It is important to note that it was created for commercial communications, this will help to explain some of it's features.  There are many manufactures of radios for DMR and they vary greatly in price.

DMR-Marc was the first DMR network for amateur radio and is a very popular network still.  There is a newer network called Brandmeister.  The 2 different networks work completely different from each other.  The DMR-Marc network is centrally controlled where the Brandmeister is more flexible and open. 

DMR is the fasted growing digital mode, mostly because the radios for DMR are cost effective.  The other mode radios start at around $300 and go up.  You can get a DMR handheld radio for under $90 delivered.

System Fusion

Mostly referred to as Fusion is the newest digital radio mode.  It was designed by Yaesu and is not an open standard.  Yaesu is the only manufacturer of radios for this mode.  Yaesu repeaters are true multi-mode capable and can replace an existing analog repeater while still providing digital capabilities.  It can also transcode an incoming digital signal to analog or an incoming analog to digital or it can transmit what it receives, no matter if it is digital or analog.

Yaesu offered a special price to radio clubs and groups.  You could get the repeater for $500.  Clubs with old repeaters and looking toward digital saw that as a great time to update their repeaters.  Because of that there are lots of System Fusion repeaters around.  But most of them still only have FM analog users on them.

The following is a comparison chart of features of each mode then after the chart I discuss each feature listed and go into more detail on each mode.

 

Feature / ItemD-StarDMR-Marc / BrandmeisterFusion Wires-X
Ease Of UseEasyEasyEasy
Ease Of ProgrammingEasyMore Difficult Easy
Cost$299 - $899*$79 - $199$299 - $700
FlexabilityHighLow/HighHigh
SurvivabilityHighLow/MediumLow
ExtendabilityHighLow/MediumLow
Multiple ManufacuresFewLotsOne
Access The Network via "Non Radio"YesNo / YesNo
Multi-band Radios AvailableYesYesYes
Field ProgammableYesSomeYes
ConnectabilityYesYesYes
Voice QualityGoodGreatGreat
Digital IDYesNoYes
GPSYes** NoYes
Can Send DataYes** NoYes
Bandwidth6.2512.512.5 / 6.25
Concurrent Voice Channels121
Error CorrectionGoodGreatGreat
Mixed Mode RepeatersNoWith LimitationsYes
Ease of Multi-UserGoodPoorGood

* There are many radios that cost up to $1200 but are typically only used for commercial radio services.  These radios can be programmed to work just fine but are not common for amateur radio.

** There are a lot of radios that support this feature but because the protocol does not have a callsign within the data it does not meet the FCC requirements for ID which means it is illegal to send GPS data or regular data packets.

Now lets go through each of the features and talk about each of the modes and why I rated them the way I did.

Ease Of Use

All of these modes are easy to use.  They are different than analog so it takes some getting used to but none of them are difficult to use.  If I had to pick the one that is easiest to use, it would be DMR.  As we will discuss in more detail below, DMR is not as flexible and therefore, it is easier to use and more structured.

Ease Of Programming

It is a bit of a mixed bag in this category.  D-star is not hard to program, however, there is a new concept that you have to understand first and that is routing.  With D-star you can talk to your local repeater, another repeater, a reflector which can have 10 or hundreds of repeaters connected to it or even an individual person.  This sound complex and complicated but once you understand that your gateway is attached to the repeater you are talking to, it is very simple.

I put DMR into the more difficult category because depending on the radio you have depends on how difficult it is to program.  The concepts initially sound simple but it is complex to implement.  You have to know what each repeater is carrying as far as talk groups and on which timeslot, etc.  The other thing is, some of the commercial radios that do DMR like Motorola require some very expensive software to program them ($180 for 3 years) unless you have a friend that has it and is willing to program it for you.  Once you understand the concept of DMR it is not hard to program, just takes a lot more work.

For Fusion, programming is not much more difficult than an analog repeater, because by itself System Fusion has no connect-ability and it is nothing more than a repeater.  If your repeater has Wires-X installed it is a little more complicated but for just the radio portion, it is just as simple as analog.

Cost

Again, this is a bit of a mixed bag and even within each mode.  For D-star, the primary manufacturer has been Icom, there are other manufactures like Kenwood that manufacture a handheld D-star triband radio.  There are also other manfucatures of add on boards for other radios.  The Icom gear I would say is in the medium to high range.  However, for around $100 you can get a USB based device that you plug into your computer and you are on the D-Star network and can talk with your computer to any repeater, reflector, etc.

An entry level handheld for D-star is around $300.

The cost of DMR radios vary greatly, there are many manufactures of radios for DMR.  You can get a Tytera radio for less than $100 or go up to a Motorola radio that is above $500 approaching $1000.

With Yaesu being the only manufacturer of radios for System Fusion, you are limited.  The entry level handheld radio for System Fusion is around $300.

Flexibility

This is a category where I may get some flack, I rated both D-star and System Fusion high and DMR mixed between low and high.  I will explain my reasoning behind this.  On D-star, if I want to listen to a specific reflector or connect to a repeater anywhere in the world I can do that through my local repeater, my hotspot (more on this later), devices connected to my computer, etc.  If I am using my local repeater, I do not have to have the repeater owner do anything.

System Fusion works similarly if there is a Wires-X node attached to the repeater.  There is nothing required of the repeater operator and you can go anywhere at any time.

DMR-Marc has no flexibility.  The repeater operator decides what talk groups he wants to allow, which ones are pinned up (always on) and on what timeslot.  He tells the C-bridge operator what he wants and that is what you get.  If you have a friend that is on a different talk group, to bad, so sad you cannot go to it.  What is available is fixed and not flexible at all.

Brandmeister has the flexibility, there are things the repeater operator can do to limit what talk groups are on the repeater but in most cases you can kerchunk any Brandmeister talkgroup and be able to listen to it on the repeater until it times out due to lack of activity.

You have to remember that DMR was created for commercial use where they do not want the flexibility.  They want the user to not have to think about anything, pick your channel and use it.  This is the model that for the most part DMR-Marc follows.  Although, there is some cross network connections being created.  So all this could change again in the next 2 years.

Survivability

When I talk survivability I am referring to in the event network issues or natural disaster occur.  Each mode works very differently and each have it's pro's and cons.

Just to note, every mode can survive on it's own as a local repeater.

D-star uses regular internet DNS to connect it's nodes.  If one node goes down, it does not affect your ability to connect to another one.  Of the 3 Modes, this is the most survivable mode, there is no reliance on a central control system.

DMR-Marc requires it be connected to a C-bridge.  I think some explanation is required here.  Unlike the Fusion and D-Star repeaters, DMR-Marc requires a central controller called a C-bridge to function.  Think of it like the dumb terminals of old mainframes that displayed the data and took input but sent it all back to the main computer to process.

The problem is if the C-bridge becomes unavailable the repeater can only work locally, it can't go around the C-bridge to other repeaters that are still working.  So as an example, if your repeater is connected to a C-bridge in Boston along with 100 other repeaters up and down the east cost, if something happens, natural disaster, terror action or someone accidentally cuts the cable to the data center, 100 of the east coast DMR repeaters just went offline as a network until that is fixed.

Because of the dependency on the central control, I rated DMR-Marc as a low.

Now, Brandmeister does not use a C-bridge architecture.  However, there are master servers spread around the globe that a repeater connects to.  In the configuration of a Brandmeister repeater you enter a primary and a secondary server.  So if the primary goes down, the repeater should keep working.  If both primary and secondary go down then the repeater is in standalone mode.

I rated System Fusion as a low also, I know I just said it has more logic, what gives right?  Well, there are 2 servers, one in Tokyo Japan and one in Florida that are the directory servers for Wires-X.  When the node software starts up, it looks to these directory servers to pull down all of the nodes and rooms that are available.  Without these lists the node does not know how to connect to another node or room.

Wires-X itself is a peer-to-peer communication and does not rely on the central servers to transfer voice data around.  If the central servers would go down after the node has downloaded the directories, it would not affect the node until the node restarted or wanted to download a list of updates nodes/rooms.

Extendability

So I need to explain what I mean by extendability.  What I mean by extendability is anything beyond a radio to repeater.  What other options are there to extend access to the network.

For all 3 modes, there is a device called a DV4Mini (US Seller, German Seller) that allows you to access the network for D-Star, DMR and System Fusion plus a couple of others.  To use this you must have a radio that can operate in the UHF range for the mode you want to use.  So you must have a D-star, Fusion or DMR radio in addition to the DV4Mini.  There is also a DV4MiniAMBE that will allow you to use just a headset and microphone on your computer and not a radio.

Since my original post in 2016 there have been many different devices that have been created to allow the digital modes to be accessed without a local repeater.  Here is a short list of the popular ones: Bluestack, Openspot, Pi-Star with a number of different radio boards and there are more!

So why rate DMR-Marc and Fusion low?

DMR-Marc is still for the most part a closed network.  This in turn helps to create a more reliable network.  As of this time, with the exception of a few talkgroups that are linked to other networks, there is no way into or out of the DMR-Marc network except via a repeater.  With Fusion, yeah you can talk digital but no Wires-X.  Also, in both modes, you cannot easily change talk groups or rooms from RF, you have to change it in the software.

Now with D-star and Brandmesiter, there are tons of different ways to get on the network and it seems like there are new ones coming out every week.  The DV4Mini will work but you can also get DVAP's, DVMega boards that you connect to a Raspberry pi and have your own mini hotspot.  For D-star there are USB dongles like the Star*DV that plug in via USB and you can connect up a Icom Microphone and use it just like a radio over the internet from anywhere.

If you want to do more of the computer thing with a headset there are a number of USB dongles like the ThumbDV, DVDongle, and there are many many more.  If you wanted to create your own repeater or high powered hotspot, free software on a raspberry pi and a low cost GMSK modem and one or two radios that have the din data plug in the back you are up and working.  I have a 20 watt hotspot that I can reach for miles around, a battery powered portable hotspot I plug into my lighter in my car to charge.  Using a wireless hotspot from my cell carrier, I have d-star and Brandmeister anywhere I go as long as there is cell service or a repeater.

If you are an experimenter, then of the 3 modes, D-Star is the way to go.

Multiple Manufactures

Of all of the modes, DMR has the most manufactures of radios at current.  Because of the large number of manufacturers you have a wide range of prices as well.  The low end Chinese radios come in below $100 but the high end and very reliable ones like Motorola still up close to the $1000 Range if purchased new.

Icom is by far the main manufacturer for D-Star, if it was not for them it would be more like D-what?  Kenwood now makes a triband handled that has D-star built in.  Other manufacturers have cards you can install to make them D-star capable but none are nearly as popular as the Icom radios.  

As mentioned before Yaesu is the only manufacturer for System Fusion.

Access The Network via "Non Radio"

This goes along with the extendability above.  At current D-Star and Brandmeister are the only modes that have the ability to connect to it without a radio involved.

Multi-Band Radios Available

Since my first post in 2016 things have changed in this category.  In 2016 this category was an oddity to me.  Both D-star and System Fusion have radios that work on both VHF and UHF.  However, DMR did not.  So if you live in an area where you have both VHF and UHF repeaters you need to buy 2 different radios if you want to work both bands.

Why was this?  I do not have an official answer but it would make sense if the radio is for business use, your repeater is only going to be on one band so why pay for a radio that can support more than one band?  This can become a challenge depending on where you live.  However, more than 90% of DMR repeaters are UHF.  But there are still some VHF repeaters out there.  Some organizations have good reason to stick with VHF, but it is not the norm.  So if you live in one of those areas where you have both, you will need to buy 2 radios and label one VHF and one UHF.

Since 2016, multiple manufactures are now making dual band DMR radios.  However be sure to do your research on the radios before purchasing something.  I am not going to mention any brands or models because the posts live here for a long time.  But as of this writing, some of the dual band radios are having problems.  Also, a trackball is not a good user interface solution for a radio.  Just Sayin....

Field Programmable

The D-Star and Fusion radios are all field programmable.  For DMR it is a bit of a tossup.  Some of the new DMR radios allow you to program them from they keyboard, the ones that do come by default not allowing you to program them, you have to use the PC programming software to turn on that feature.

Other DMR radios do not have the option to field program them at all.  So why is this....  It goes back to it being designed for commercial business use.  You would not want your bus driver being able to change the programming in the radio.  You want to control how the radio is configured so everything is standard, etc.

Connect-ability

All of the modes have the ability to connect to anywhere in the world if they are attached to the internet.  Each mode does it differently but there is a big difference between D-Star and Fusion compared to DMR.  It is like a push pull model.  In D-Star and Fusion, you tell the repeater or other device you are connected to what you want to connect to and it goes and does that.  Both of these modes can connect to anywhere and anything.  You find a new repeater was put in timbuctu and you can connect to it.

In DMR-Marc, it is pushed to you, you cannot do a link request, you can listen to what talk groups are setup for your repeater.  To get a new talk group added you have to talk with the repeater operator and get him to ask the C-Bridge owner to add a new talk group, assuming the repeater operator wants to do that.

Brandmeister for the most part has changed this.  In Brandmeister you can specify what talk groups you want permanently linked to a repeater.  Unless setup otherwise, anyone can kerchunk a talk group and it will be made active on the repeater until it reaches the inactivity timeout.  So there is no need to talk to the repeater owner or a c-bridge operator.

Voice Quality

In this category, DMR and Fusion have excellent voice quality.  It is noticeable especially when you go from analog to either of these modes.  D-Star has good audio, much better than analog, but sounds a bit mechanical.

Digital ID

D-Star and Fusion both send your callsign in digital format every time you key up the Mic.  According to the FCC this qualifies as an ID.  So technically you do not have to voice ID on either D-Star or System Fusion.   However, it is still good to keep in practice for when you are back on analog.

DMR sends a radio id and your subscriber ID (CCS7 ID) in data, not your Callsign.  This does not meet the FCC ID requirement so you must still voice ID when using DMR.

User Data

On D-Star and Fusion, when you hear a contact, there is a header that your radio receives that has details about the user that is connecting.  From that you can see the name of the person, their call sign, a short message and if they have GPS enabled, you can even see direction and distance information.

With DMR, their subscriber ID is what you get, to see who is calling you would have to enter into your contacts everyone you know, otherwise there is no user information available.

There are custom versions of firmware available for some radios that will allow you to upload the entire CCS7 user database to your radio so you can see who you are talking to.  Some of the new radios also come with enough memory to upload the entire database to the radio and they will show you who you are talking to.

GPS

There are radios available for all modes that can provide GPS data.  However, since DMR does not meet the ID requirement that are required, it is illegal to send the GPS data when using the radio under Part 97 Rules.

In both D-Star and System Fusion, the GPS data is used to display the direction and distance between 2 contacts.  In addition, in D-star you can click on the orange link in the dashboard and view it on a map.  Also, the GPS data in D-star that they call DPRS is transmitted to APRS.  So if your D-star radio has GPS and is enabled, you can look on sites like aprs.fi to see your location reported.

Can Send Data

All of the modes have some form of data available.  In D-star you can send up to 9600 Kbs data.  It is just data not formatted messages, etc.  In DMR you can send text messages.  In fusion you can send formatted messages, pictures, etc.

It would seem more thought was put into System Fusion as far as using the data features without connecting it to a computer to generate formatted data.

Bandwidth

Each mode uses the bandwidth differently.  However they are all narrow band compliant.  Not yet a requirement under Part 97 Rules but it could become a possibility.  D-Star uses 6.25 Khz of bandwidth that is 9600 Kbs separated into 2  data channels, one for low speed data and one for the voice data.

DMR uses 12.5 Khz that is split in half, one for time slot one and one time slot two.

System Fusion uses either 6.25 or 12.5 Khz.  In regular voice mode, 6.25 Khz is used.  If you are sending data and talking or are using the mode called voice wide then you are using 12.5 Khz

Concurrent Voice Channels

DMR is the only mode that can support more than one voice channel at a time.  It can support 2 different voice channels in the same 12.5 Khz bandwidth.  DMR refers to these as Timeslot 1 and Timeslot 2.

Error Correction

All of these modes have Forward Error Correction (FEC) but not all of them are created equal.  From my experience DMR has the best and can recover from bit errors quickly making for a great sound.  Fusion is a close second with great sound, especially in Voice Wide mode.  D-Star trails behind them, If you are on the fringe and get some packet loss D-Star like the other modes puts out something unintelligible (called by Many R2D2).  However, D-Star takes longer to recover when that happens than the other modes.

Mixed Mode Repeaters

D-Star does not support mixed mode at all.  It is digital all the time.  DMR and System Fusion both do but not equally.

DMR can run in mixed mode but when you setup to support both analog and digital you lose the networking ability that makes these digital modes so compelling.

System Fusion was designed to support mixed mode.  Their plan is to replace aging analog repeaters with one that can do both analog and digital in the hopes that people would start using digital because it was there.  Because of that, their handling of mixed modes is great.  There are lots of options around how the repeater handles it and there is transcoding from one to the other, etc.

Ease of Multi-User

I wanted to add this to the end because this is one thing that really bothers me.  On both D-Star and System Fusion, when you ask the repeater to connect to a different location, anyone that is listening on that repeater hears that you are there and can tell you have moved the repeater.  If they want to move it, it is proper etiquette to ask if the channel is in use and if not go ahead and link it somewhere else.

In DMR-Marc this is not the case.  DMR-Marc uses talk groups and the repeater operator specifies which talk groups are on which timeslot and which ones are connected full time or (pinned up).  On your DMR radio you select what talk group you want to listen to.  However, say you want to listen to North America and that talk group is not pinned up all the time, you have to tell the repeater by keying down on that talk group. 

The C-Bridge then will stop sending the current talk group to the repeater and start sending North America.  It will keep sending North America until either there is no activity from the repeater on that talk group (you do not key down for a period of time) or someone requests a new talk group.

So you are listening and having a QSO on North America and suddenly it is like the person you were talking just stopped talking.  So while you are having a QSO on North America, I key down on TAC310 to talk to my friend.  I unknowingly just took over the repeater, disconnected you from North America and told the C-bridge that the active talk group is now TAC310.

You do not know what happened and I do not know that it happened.  I have had this happen to me a couple of times.  If the repeater is not busy and with lots of people then the likelihood is lower but in large metropolitan areas the repeaters are busy and it happens.

With DMR, you have to setup a scan so that you can scan all of the possible talk groups on the repeater, but if you do not like one of the talk groups because it it too busy, etc and do not scan it, the likelihood continues.

Now What?

I just went down a long list good and bad things about each mode.  There is not one that stands out above the other, they are all legitimate modes, you have to decide what is right for you.

I assume if you read this far you are likely one of 2 people.  An amateur radio operator that is investigating the digital modes or maybe a club or repeater organization considering putting up a new digital repeater or replacing an existing one with a digital mode.  I will break this down into some things to think about for each

Amateur Radio Operator

The first thing you should do is go to repeaterbook.com and check to see what types of digital repeaters are around you.  More than likely you would want to pick a mode that you can use in your area.  You may live in an area that has all of the modes available or may live in an area that has none.

If you live in an area that has none, then your only option for DMR or Fusion is to look at the DV4Mini.  For D-Star the DV4Mini is still an option but if you do not want to spend the money on a radio and the DV4Mini, look into some of the USB dongles.  If you do not want to dedicate a computer to the job, you could look at putting a DVMega board on the $35 raspberry pi and then you can walk around your house with an HT talking all over the world.

If you live in an area with all of the modes, you have a harder decision to make.  If you like flexibility,extendability and/or love to experiment, shy away from DMR and for experimenter, get closer to D-Star.

If you want to be able to just turn it on and not have anything confusing (after it is setup) look at DMR.  DMR radios have 2 knobs, volume and typically a 16 channel knob.  You pick the talk group from the channel knob and that is it.  

Club or Repeater Group

From a Club or Repeater Group you have to first think about it's purpose.  Is it mainly for the club members to Ragchew and talk to people around the world or are you looking at more as a communication system when SHTF.  If you are looking more towards an emergency communication system then I would look at DMR.  It is much more controllable.  You can setup talk groups for the different agencies and groups.  If you are going to have more than one, I would setup your own C-Bridge on your network so that if there is some kind of natural disaster your repeaters remain connected but when all is good you can still enjoy the communication to the outside world.

If you do decide to go DMR, the question is do you go UHF or VHF.  The biggest reason I have seen for people going VHF is because the repeater group or club already have a VHF repeater and by sticking to the same band, the DMR radio can be setup for analog and still use the repeaters in the same band.

Also, really think out your talk group layout.  You can put talk groups on either timeslot.  It might be that you put a local (across your repeater system) talk group pinned up on time slot 1 and on time slot 2 you use for things like TAC310, etc.

In DMR, the etiquette is, you make contact on the larger talk groups like US Nationwide but for an extended QSO you move to a Talk Around Channel (TAC) so that the US Nationwide is free.  This can be the same etiquette you apply to your own talk group for your organization.

Ok, so you are wanting it more ragchew, fun and experimentation....

Is it going to replace and existing repeater?  If so, how busy is the repeater?  If you have regular users, how are they gonna feel if you replace it with a repeater that only does digital?  Keep that in mind.  At the same time, adoption of digital is slower if you give them the option of using both analog and digital on the same repeater.  

Does the repeater site have internet connectivity?  If not, there really is only one option of the 3 modes that will get you connected to the world without internet.  That is System Fusion.  The Wires-X box that connects to the internet does not have to be directly connected to the repeater.  For D-Star and DMR, you have to have an internet connection at the repeater.

Assuming you have internet, is the main purpose so you can connect outside your area and connect to groups of other repeaters?  If so, D-Star is the way to go.  It is the best connected, most resilient Mode of the 3 and it is also the most flexible.  Brandmeister is 2nd because it is a more open network that is growing not only in the number of users but in the number and types of connections.  Fusion is a distant 3rd with DMR-Marc after it.  I only say that DMR-Marc follows Fusion because it is not flexible but fixed in what it provides.  Meaning you cannot decide to connect to Germany today, Australia tomorrow, etc unless the repeater has talk groups already present for them.

There are lots of things to think about and much of it is confusing at first.

The Future?

You can never predict the future, especially when it comes to technology.  My best guess would be that Fusion is going to struggle and may go the way of BetaMax.  D-Star is not growing as quickly as it was.  DMR is the fastest growing digital radio technology and I do not see that stopping anytime soon.  It seems the DMR-Marc people are hardcore and are a lot of professional radio people that like the Motorola hardware.

I do not want to predict a winner of the modes as I hope there is not a single winner.  Each mode resonates with each person differently.  And it also depends on what is available to you, where your friends hang out, etc.

PS.

I said in the beginning that not until the end will you know my preferred mode.  If I did an objective view in this blog post you should still not know....

My goto when not analog is evenly split between D-Star and DMR.  I have a D-Star, Fusion and DMR radio in my car, and I have at least 2 handhelds for each mode as well.  I use all of the modes.  When at home I have a house based Pi-star hotspot, a portable Pi-star hotspot with battery, charger and cellular modem, a 20 watt D-Star hotspot and 2 openspot devices.  So I give all modes equal time.  I sit here at my desk with a HH for each mode right here.

Most of my friends are on D-star, in fact we get on D-star to talk about DMR.  Not because DMR is bad, it is awesome.  

One more thing...  In a SHTF situation, the goto should always be analog.  Make sure you keep a great analog repeater around for those situations.

How do you keep your Shack organized?

I am about to embark on the task of re-organizing my shack yet again, this will be the 4th or 5th time.  I seem to keep acquiring new gear and running out of space.  Not to mention all of the cables that go along with it.

When I put up the tower I ran a bunch of LMR 400 cable.  That stuff is not flexible and I have a ton of rf cables everywhere.

I am going to attempt to put a small rack under the desk and rack mount the transcievers and build a panel for the rf connectors and label them.  I am not sure if any of this will help though.

Most of my radios have remote heads so that helps some, I can keep the radio out of site but there are just so many wires.

Here was the last re-org when it was just getting started:

After it was done it was not too bad:

Since then I have added the new antennas on the tower and moved a few things around.

I am curious how you keep your shack organized and non cable cluttered.

Post your suggestions and pictures as well if you have some.

D-star, DMR, Fusion, Which is right for you?

Updated Content

This post was originally created in February of 2016.  Lots of things have changed since then.  Here is a link to a an updated post with information from February 2018: http://www.mikemyers.me/blog/2016/2/19/d-star-dmr-fusion-which-is-right-for-you-7nhdl

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If you are an amateur radio operator and have not been living under a rock, then I am sure you have heard of one of the digital modes: D-Star, DMR or Fusion.  You may be wanting to dip your toes into the digital modes water but not sure which pool to dip them in.  This blog post is intended to present a fair unbiased opinion on each of the modes.  

Not until the end will you learn my preferred mode.  I use all of the modes I will discuss.  There are additional digital modes like P25, and Nexedge that I have not used and are also much less prevalent that I will not discuss.  I do not have enough knowledge of those modes to represent them.

Also, I want to make sure up front that this is not intended to bash any one mode.  I like all forms of technology and really do not like the people that are so biased toward one that every other mode is bad.  Each of these modes has a place and my goal is to help you decide which one fits you the best.

I am going to start off with a quick synopsis of each of the modes we are going to discuss then we will get into the comparison.

D-Star

Of the 3 modes we are going to discuss, D-Star is the oldest.  It was created by the Japan Amateur Radio League (JARL) and is an open standard.  It is important to note that is was created for Amateur Radio.  Most people relate Icom with D-star as they have been the primary manufacturer of D-Star equipment, however, they are just a manufacturer that has implemented this open standard into their products.  There are other manufactures that make add-on boards for D-star.  There is also a lot of other solutions for getting on D-Star that do not require a radio or local repeater.  We will discuss these later.

DMR 

Digital Mobile Radio is known as DMR and sometimes you will hear it referred to as MOTOTRBO.  MOTOTRBO is the motorola implementation of the DMR protocol.  DMR originated as a business communication standard in Europe.  It is important to note that it was created for commercial communications, this will help to explain some of it's features.  There are many manufactures of radios for DMR and they vary greatly in price.

System Fusion

Mostly referred to as Fusion is the newest digital radio mode.  It was designed by Yeasu and is not an open standard.  Yeasu is the only manufacturer of radios for this mode.  Yeasu repeaters are true multi-mode capable and can replace an existing analog repeater while still providing digital capabilities.  It can also transcode an incoming digital signal to analog or an incoming analog to digital or it can transmit what it receives, no matter if it is digital or analog.

Yeasu offered a special price to radio clubs and groups.  You could get the repeater for $500.  Clubs with old repeaters and looking toward digital saw that as a great time to update their repeaters.  Because of that there are lots of System Fusion repeaters around.  But most of them still only have FM analog users on them.

The following is a comparison chart of features of each mode then after the chart I discuss each feature listed and go into more detail on each mode.

 

Feature / ItemD-StarDMRFusion
Ease Of UseEasyEasyEasy
Ease Of ProgrammingMediumLow High
CostLow-MediumLow-HighMedium
FlexabilityHighLowHigh
SurvivabilityHighLowLow
ExtendabilityHighLowLow
Multiple ManufacuresFewLotsOne
Access The Network via "Non Radio"YesNoNo
Multi-band Radios AvailableYesNoYes
Field ProgammableYesSomeYes
ConnectabilityYesYesYes
Voice QualityGoodGreatGreat
Digital IDYesNoYes
GPSYesNoYes
Can Send DataYesNoYes
Bandwidth6.2512.512.5 / 6.25
Concurrent Voice Channels121
Error CorrectionGoodGreatGreat
Mixed Mode RepeatersNoWith LimitationsYes
Ease of Multi-UserGoodPoorGood

Now lets go through each of the features and talk about each of the modes and why I rated them the way I did.

Ease Of Use

All of these modes are easy to use.  They are different than analog so it takes some getting used to but none of them are difficult to use.  If I had to pick the one that is easiest to use, it would be DMR.  As we will discuss in more detail below, DMR is not as flexible and therefore, it is easier to use and more structured.

Ease Of Programming

It is a bit of a mixed bag in this category.  D-star is not hard to program, however, there is a new concept that you have to understand first and that is routing.  With D-star you can talk to your local repeater, another repeater, a reflector which can have 10 or hundreds of repeaters connected to it or even an individual person.  This sound complex and complicated but one you understand that your gateway is attached to the repeater you are talking to, it is very simple.

I put DMR into the low category because depending on the radio you have depends on how difficult it is to program.  The concepts initially sound simple but it is complex to implement.  You have to know what each repeater is carrying as far as talk groups and on which timeslot, etc.  The other thing is, some of the commercial radios that do DMR like motorola require some very expensive software to program them ($300 for 3 years) unless you have a friend that has it and is willing to program it for you.

For Fusion, programming is not much more difficult than an analog repeater, because by itself System Fusion has no connect-ability and it is nothing more than a repeater.  If your repeater has Wires-X installed it is a little more complicated but for just the radio portion, it is just as simple as analog.

Cost

Again, this is a bit of a mixed bag and even within each mode.  For D-star, the primary manufacturer has been Icom, there are other manufactures of add on boards for other radios.  The Icom gear I would say is in the medium to high range.  However, for around $100 you can get a USB based device that you plug into your computer and you are on the D-Star network and can talk with your computer to any repeater, reflector, etc.

There are 2 companies that say they are coming out with D-Star radios soon, if that happens the pricing in this market could change.  An entry level handheld for D-star is around $300.

The cost of DMR radios vary greatly, there are many manufactures of radios for DMR.  You can get a Tytera radio in the low $100s or go up to a Motorola radio that is above $500 approaching $1000.

With Yeasu being the only manufacturer of radios for System Fusion, you are limited.  The entry level handheld radio for System Fusion is in the mid $300's

Flexibility

This is a category where I may get some flack, I rated both D-star and System Fusion high and DMR Low.  I will explain my reasoning behind this.  On D-star, if I want to listen to a specific reflector or connect to a repeater anywhere in the world I can do that through my local repeater, my hotspot (more on this later), devices connected to my computer, etc.  If I am using my local repeater, I do not have to have the repeater owner do anything.

System Fusion works similarly if there is a Wires-X node attached to the repeater.  There is nothing required of the repeater operator and you can go anywhere at any time.

DMR has no flexibility.  The repeater operator decides what talk groups he wants to allow, which ones are pinned up (always on) and on what timeslot.  He tells the C-bridge operator what he wants and that is what you get.  If you have a friend that is on a different talk group, to bad, so sad you cannot go to it.  What is available is fixed and not flexible at all.

You have to remember that DMR was created for commercial use where they do not want the flexibility.  They want the user to not have to think about anything, pick your channel and use it.  Unfortunately this does not match the experimentation part of amateur radio.

Survivability

When I talk survivability I am referring to in the event network issues or natural disaster occur.  Each mode works very differently and each have it's pro's and cons.

Just to note, every mode can survive on it's own as a local repeater.

D-star uses regular internet DNS to connect it's nodes.  If one node goes down, it does not affect your ability to connect to another one.  Of the 3 Modes, this is the most survivable mode, there is no reliance on a central control system.

DMR requires it be connected to a C-bridge.  I think some explanation is required here.  Unlike the Fusion and D-Star repeaters, DMR requires a central controller called a C-bridge to function.  Think of it like the dumb terminals of old mainframes that displayed the data and took input but sent it all back to the main computer to process.

The problem is if the C-bridge becomes unavailable the repeater can only work locally, it can't go around the C-bridge to other repeaters that are still working.  So as an example, if your repeater is connected to a C-bridge in Boston along with 100 other repeaters up and down the east cost, if something happens, natural disaster, terror action or someone accidentally cuts the cable to the data center, 100 of the east coast DMR repeaters just went offline as a network until that is fixed.

Because of the dependency on the central control, I rated this as a low.

I rated System Fusion as a low also, I know I just said it has more logic, what gives right?  Well, I recently was told that the central control for Wires-X is in Tokyo Japan.  This is nothing against Tokyo Japan, but there is a lot of things that can happen to the internet between the US and Japan.  Also, what does that do for latency?  So in addition to be a central controlled system, it is very far away and just asking for trouble.

Extendability

So I need to explain what I mean by extendability.  What I mean by extendability is anything beyond a radio to repeater.  What other options are there to extend access to the network.

For all 3 modes, there is a device called a DV4Mini (US Seller, German Seller) that allows you to access the network for D-Star, DMR and System Fusion plus a couple of others.  To use this you must have a radio that can operate in the UHF range for the mode you want to use.  So you must have a D-star, Fusion or DMR radio in addition to the DV4Mini.  So why rate DMR and Fusion low?

The DMR currently available on the DV4Mini is tied to the Hytera DMR network and most repeaters are tied in the DMR-Marc network.  There is only one talk group that connects between the 2, 4639 Nationwide.  So, you can talk anywhere on the Hytera network but that is not the most common network in use.  With Fusion, yeah you can talk digital but no Wires-X.  Also, in both modes, you cannot easily change talk groups or rooms from RF, you have to change it in the software.

Now with D-star, there are tons of different ways to get on the network and it seems like there are new ones coming out every week.  The DV4Mini will work but you can also get DVAP's, DVMega boards that you connect to a Raspberry pi and have your own mini hotspot, there are USB dongles like the Star*DV that plug in via USB and you can connect up a Icom Microphone and use it just like a radio over the internet from anywhere.

If you want to do more of the computer thing with a headset there are a number of USB dongles like the ThumbDV, DVDongle, and there are many many more.  If you wanted to create your own repeater or high powered hotspot, free software on a raspberry pie and a low cost GMSK modem and one or two radios that have the din data plug in the back you are up and working.  I have a 20 watt hotspot that I can reach for miles around, a battery powered portable hotspot I plug into my lighter in my car to charge.  Using a wireless hotspot from my cell carrier, I have d-star anywhere I go as long as there is cell service or a repeater.

If you are an experimenter, then of the 3 modes, D-Star is the way to go.

Multiple Manufactures

Of all of the modes, DMR has the most manufactures of radios at current.  Because of the large number of manufacturers you have a wide range of prices as well.  The low end Chinese radios come in in the mid $100 range but the high end and very reliable ones like Motorola still up close to the $1000 Range if purchased new.

Icom is by far the main manufacturer for D-Star, if it was not for them it would be more like D-what?  Other manufacturers have cards you can install to make them D-star capable but none are nearly as popular as the Icom radios.  There has been rumor of 2 other companies entering the D-Star market this year.

As mentioned before Yeasu is the only manufacturer for System Fusion.

Access The Network via "Non Radio"

This goes along with the extendability above.  At current D-Star is the only mode that has the ability to connect to it without a radio involved.

Multi-Band Radios Available

This category is an oddity to me and I am sure at some point this is will change.  Both D-star and System Fusion have radios that work on both VHF and UHF.  However, DMR does not.  So if you live in an area where you have both VHF and UHF repeaters you need to buy 2 different radios if you want to work both bands.

Why is this?  I do not have an official answer but it would make sense if the radio is for business use, your repeater is only going to be on one band so why pay for a radio that can support more than one band?  This can become a challenge depending on where you live.  However, more than 90% of DMR repeaters are UHF.  But there are still some VHF repeaters out there.  Some organizations have good reason to stick with VHF, but it is not the norm.  So if you live in one of those areas where you have both, you will need to buy 2 radios and label one VHF and one UHF.

Field Programmable

The D-Star and Fusion radios are all field programmable.  For DMR it is a bit of a tossup.  Some of the new DMR radios allow you to program them from they keyboard, the ones that do come by default not allowing you to program them, you have to use the PC programming software to turn on that feature.

Other DMR radios do not have the option to field program them at all.  So why is this....  It goes back to it being designed for commercial business use.  You would not want your bus driver being able to change the programming in the radio.  You want to control how the radio is configured so everything is standard, etc.

Connect-ability

All of the modes have the ability to connect to anywhere in the world if they are attached to the internet.  Each mode does it differently but there is a big difference between D-Star and Fusion compared to DMR.  It is like a push pull model.  In D-Star and Fusion, you tell the repeater or other device you are connected to what you want to connect to and it goes and does that.  Both of these modes can connect to anywhere and anything.  You find a new repeater was put in timbuctu and you can connect to it.

In DMR, it is pushed to you, you cannot do a link request, you can listed to what talk groups are setup for your repeater.  To get a new talk group added you have to talk with the repeater operator and get him to ask the C-Bridge owner to add a new talk group, assuming the repeater operator wants to do that.

Voice Quality

In this category, DMR and Fusion have excellent voice quality.  It is noticeable especially when you go from analog to either of these modes.  D-Star has good audio, much better than analog, but sounds a bit mechanical.

Digital ID

D-Star and Fusion both send your callsign in digital format every time you key up the Mic.  According to the FCC this qualifies as an ID.  So technically you do not have to voice ID on either D-Star or System Fusion.   However, it is still good to keep in practice for when you are back on analog.

DMR sends a radio id and your subscriber ID (CCS7 ID) in data, not your Callsign.  This does not meet the FCC ID requirement so you must still voice ID when using DMR.

User Data

On D-Star and Fusion, when you hear a contact, there is a header that your radio receives that has details about the user that is connecting.  From that you can see the name of the person, their call sign, a short message and if they have GPS enabled, you can even see direction and distance information.

With DMR, their subscriber ID is what you get, to see who is calling you would have to enter into your contacts everyone you know, otherwise there is no user information available.

GPS

There are radios available for all modes that can provide GPS data.  However, since DMR does not meet the ID requirement that are required, it is illegal to send the GPS data when using the radio under Part 97 Rules.

In both D-Star and System Fusion, the GPS data is used to display the direction and distance between 2 contacts.  In addition, in D-star you can click on the orange link in the dashboard and view it on a map.  Also, the GPS data in D-star that they call DPRS is transmitted to APRS.  So if your D-star radio has GPS and is enabled, you can look on sites like aprs.fi to see your location reported.

Can Send Data

All of the modes have some form of data available.  In D-star you can send up to 9600 Kbs data.  It is just data not formatted messages, etc.  In DMR you can send text messages.  In fusion you can send formatted messages, pictures, etc.

It would seem more thought was put into System Fusion as far as using the data features without connecting it to a computer to generate formatted data.

Bandwidth

Each mode uses the bandwidth differently.  However they are all narrow band compliant.  Not yet a requirement under Part 97 Rules but it could become a possibility.  D-Star uses 6.25 Khz of bandwidth that is 9600 Kbs separated into 2  data channels, one for low speed data and one for the voice data.

DMR uses 12.5 Khz that is split in half, one for time slot one and one time slot two.

System Fusion uses either 6.25 or 12.5 Khz.  In regular voice mode, 6.25 Khz is used.  If you are sending data and talking or are using the mode called voice wide then you are using 12.5 Khz

Concurrent Voice Channels

DMR is the only mode that can support more than one voice channel at a time.  It can support 2 different voice channels in the same 12.5 Khz bandwidth.  DMR refers to these as Timeslot 1 and Timeslot 2.

Error Correction

All of these modes have Forward Error Correction (FEC) but not all of them are created equal.  From my experience DMR has the best and can recover from bit errors quickly making for a great sound.  Fusion is a close second with great sound, especially in Voice Wide mode.  D-Star trails behind them, If you are on the fringe and get some packet loss D-Star like the other modes puts out something unintelligible (called by Many R2D2).  However, D-Star takes longer to recover when that happens than the other modes.

Mixed Mode Repeaters

D-Star does not support mixed mode at all.  It is digital all the time.  DMR and System Fusion both do but not equally.

DMR can run in mixed mode but when you setup to support both analog and digital you lose the networking ability that makes these digital modes so compelling.

System Fusion was designed to support mixed mode.  Their plan is to replace aging analog repeaters with one that can do both analog and digital in the hopes that people would start using digital because it was there.  Because of that, their handling of mixed modes is great.  There are lots of options around how the repeater handles it and there is transcoding from one to the other, etc.

Ease of Multi-User

I wanted to add this to the end because this is one thing that really bothers me.  On both D-Star and System Fusion, when you ask the repeater to connect to a different location, anyone that is listening on that repeater hears that you are there and can tell you have moved the repeater.  If they want to move it, it is proper etiquette to ask if the channel is in use and if not go ahead and link it somewhere else.

In DMR this is not the case.  DMR uses talk groups and the repeater operator specifies which talk groups are on which timeslot and which ones are connected full time or (pinned up).  On your DMR radio you select what talk group you want to listen to.  However, say you want to listen to North America and that talk group is not pinned up all the time, you have to tell the repeater by keying down on that talk group. 

The C-Bridge then will stop sending the current talk group to the repeater and start sending North America.  It will keep sending North America until either there is no activity from the repeater on that talk group (you do not key down for a period of time) or someone requests a new talk group.

So you are listening and having a QSO on North America and suddenly it is like the person you were talking just stopped talking.  So while you are having a QSO on North America, I key down on TAC310 to talk to my friend.  I unknowingly just took over the repeater, disconnected you from North America and told the C-bridge that the active talk group is now TAC310.

You do not know what happened and I do not know that it happened.  I have had this happen to me a couple of times.  If the repeater is not busy and with lots of people then the likelihood is lower but in large metropolitan areas the repeaters are busy and it happens.

With DMR, you have to setup a scan so that you can scan all of the possible talk groups on the repeater, but if you do not like one of the talk groups because it it too busy, etc and do not scan it, the likelihood continues.

Now What?

I just went down a long list good and bad things about each mode.  There is not one that stands out above the other, they are all legitimate modes, you have to decide what is right for you.

I assume if you read this far you are likely one of 2 people.  An amateur radio operator that is investigating the digital modes or maybe a club or repeater organization considering putting up a new digital repeater or replacing an existing one with a digital mode.  I will break this down into some things to think about for each

Amateur Radio Operator

The first thing you should do is go to repeaterbook.com and check to see what types of digital repeaters are around you.  More than likely you would want to pick a mode that you can use in your area.  You may live in an area that has all of the modes available or may live in an area that has none.

If you live in an area that has none, then your only option for DMR or Fusion is to look at the DV4Mini.  For D-Star the DV4Mini is still an option but if you do not want to spend the money on a radio and the DV4Mini, look into some of the USB dongles.  If you do not want to dedicate a computer to the job, you could look at putting a DVMega board on the $35 raspberry pi and then you can walk around your house with an HT talking all over the world.

If you live in an area with all of the modes, you have a harder decision to make.  If you like flexibility,extendability and/or love to experiment, shy away from DMR and for experimenter, get closer to D-Star.

If you want to be able to just turn it on and not have anything confusing (after it is setup) look at DMR.  DMR radios have 2 knobs, volume and typically a 16 channel knob.  You pick the talk group from the channel knob and that is it.  

Club or Repeater Group

From a Club or Repeater Group you have to first think about it's purpose.  Is it mainly for the club members to Ragchew and talk to people around the world or are you looking at more as a communication system when SHTF.  If you are looking more towards an emergency communication system then I would look at DMR.  It is much more controllable.  You can setup talk groups for the different agencies and groups.  If you are going to have more than one, I would setup your own C-Bridge on your network so that if there is some kind of natural disaster your repeaters remain connected but when all is good you can still enjoy the communication to the outside world.

If you do decide to go DMR, the question is do you go UHF or VHF.  The biggest reason I have seen for people going VHF is because the repeater group or club already have a VHF repeater and by sticking to the same band, the DMR radio can be setup for analog and still use the repeaters in the same band.

Also, really think out your talk group layout.  You can put talk groups on either timeslot.  It might be that you put a local (across your repeater system) talk group pinned up on time slot 1 and on time slot 2 you use for things like TAC310, etc.

In DMR, the etiquette is, you make contact on the larger talk groups like US Nationwide but for an extended QSO you move to a Talk Around Channel (TAC) so that the US Nationwide is free.  This can be the same etiquette you apply to your own talk group for your organization.

Ok, so you are wanting it more ragchew, fun and experimentation....

Is it going to replace and existing repeater?  If so, how busy is the repeater?  If you have regular users, how are they gonna feel if you replace it with a repeater that only does digital?  Keep that in mind.  At the same time, adoption of digital is slower if you give them the option of using both analog and digital on the same repeater.  

Does the repeater site have internet connectivity?  If not, there really is only one option of the 3 modes that will get you connected to the world without internet.  That is System Fusion.  The Wires-X box that connects to the internet does not have to be directly connected to the repeater.  For D-Star and DMR, you have to have an internet connection at the repeater.

Assuming you have internet, is the main purpose so you can connect outside your area and connect to groups of other repeaters?  If so, D-Star is the way to go.  It is the best connected, most resilient Mode of the 3 and it is also the most flexible.  Fusion is a distant 2nd with DMR after it.  I only say that DMR follows Fusion because it is not flexible but fixed in what it provides.  Meaning you cannot decide to connect to Germany today, Australia tomorrow, etc unless the repeater has talk groups already present for them.

There are lots of things to think about and much of it is confusing at first.

The Future?

You can never predict the future, especially when it comes to technology.  My best guess would be that Fusion is going to struggle and may go the way of BetaMax.  D-Star it still growing quickly and I do not see that stopping anytime soon.  DMR is growing in pockets too.  It seems the DMR people are hardcore and are a lot of professional radio people that like the Motorola hardware.

I do not want to predict a winner of the modes as I hope there is not a single winner.  DMR has a ways to go to catch up with D-star as far as footprint, users and especially the extendability.  However, DMR is the perfect solution for some people and that is awesome.

PS.

I said in the beginning that not until the end will you know my preferred mode.  If I did an objective view in this blog post you should still not know....

My goto when not analog is D-Star.  I have a D-Star radio in my car, a couple of handhelds, base stations.  However, that being said, I have 3 HH DMR radios, a fusion HH, etc.  I use all of the modes.  When at home I have a house based D-star hotspot, a portable D-star hotspot with battery, charger and cellular modem, a 20 watt D-Star hotspot, a DV4Mini running DMR and a DV4Mini running Fusion.  So I give all modes equal time.  I sit here at my desk with a HH for each mode right here.

Most of my friends are on D-star, in fact we get on D-star to talk about DMR.  Not because DMR is bad, it is awesome (except for what I mentioned above about taking over talk groups).  But I cannot reach a real DMR repeater from my basement where my office is so I have to use the DV4Mini.  However, that uses the Hytera network and some of us use a repeater which is DMR-Marc and some us DV4Mini.  On D-star, everything connects, there are no different networks so it is just easier.

The Radio Tower

Since I got back into Amateur Radio (Ham Radio) I have been wanting to put up a tower to mount my antennas on.  I had been making due with some homemade antenna mounts using PVC pipe.  Over the summer the pipes started to bend with the heat and weight of the antennas.

I had been looking around for a used antenna from a silent key (Amateur radio Operator that has passed).  I found one on Craig's List that was never even put into the ground.  It had 4 10 ft sections and the ground post.

This is not a really big antenna tower and looks very similar to a lot of old TV antenna towers.  It is built a bit stronger than those but from a distance it really looks the same.

With the help of my brother in law and step father, the first saturday it got stood up, mounted to the house, guy wires connected and cemented into the ground.  A couple of antennas were mounted but most were put up a couple of weeks later.

First Week (CLICK TO SEE FULL IMAGE)

As you can see we used a rented pull behind man lift which made the process so much easier.  We basically assembled the tower on the ground and used the lift to pick it up assembled and lifted it into the 3 ft hole.  After getting it mounted to the house and putting cement in the hole, things like the guy wires were added and just a few antennas.

2 weeks or so later the rest of the antennas were added.  Again we rented the tow behind man lift from Rentals Unlimited.  That makes it so quick and easy.  It is $250 to rent for the day but it is worth it.  That Saturday I also had the help of my Father In-Law with some of the grunt work like digging holes, etc.

BTW...  I did not mention that I got the 40ft tower and the base for $400.  That is really inexpensive.  The only problem is I do not know who the manufacturer is.

Here are pictures from the completed installation on the 2nd Saturday:

CLICK FOR FULL IMAGE

CLICK FOR FULL IMAGE

You will notice the large bundle of cables at the bottom that look like a mess.  I did clean that up:

CLICK FOR FULL IMAGE

This is the last picture I took.  There is still some cleanup needed in this picture, I did manage to clean it up some more after this picture was taken.  I am still considering adding another 10 or 20 feet to the tower so I have not shortened the cables yet.  If I can ever figure out who the manufacturer is I might grow the tower another 20 feet.

Everything has been grounded and those thin cables you see running into the house have now been replaced with LMR-400 cables to match what is running up the tower.

The main reason I am still wanting to add some height is I am close to the top of a hill, I need just a little more height to get a clear view over the hill.  Particularly for the RocketDish to the MAIPN network.  It is pointing directly at the front of a Catholic Church:

That image is from a camera that is mounted directly below the RocketDish and pointing the same direction.  Just after church the ground drops off into a valley so the church and the few trees around it are what would be impacting my connection to Braddock Heights MAIPN POP.

Here is what I have mounted on the tower as of the time the pictures were taken:

  • The dish is a Ubiquity RocketDish with a Rocket M5 radio that is pointing towards Braddock Heights MD where there is a MAIPN node.
  • At the very top is a 7 band HF vertical antenna.  In the spring I am considering replacing it with a 3 band beam and moving this to the ground.  I have found that this works better with the ground plane actually in the ground vs being high on a tower.
  • There is a 3 band (6m, 2m, and 70cm) on the right top of the tower.  This is currently connected to an ID-880h and is my main D-Star radio when I am not using a hotspot.
  • There is a 2 band (2m/70cm) on the top left.  This is connected to a 50 Watt TYT 9800D and is my primary 2M/70CM FM radio.
  • There is a QFH antenna for receiving weather satellites.
  • There is a 440 antenna and a 2m Jpole that are connected together with an MFJ combiner.  This is connected to a Yeasu radio that is used for experimenting with digital data mostly.  It will be the radio for the high power hotspot and can do packet, etc.
  • There is a homemade antenna for receiving ADSB data from airplanes.
  • It is hard to see but there are also 2 ubiquity IP cameras just under the dish.  One facing the same direction as the dish and the other one facing the opposite direction.
  • There is a Oregon Scientific anemometer, wind direction and temperature and humidity sensor.
  • Down the tower a little bit there is a 80 meter dipole mounted.
  • Not too far below that there is a 40 meter wire antenna (gray box).
  • A little further down are 3 mag mount antennas for 2m/70cm on ground planes.  These are mainly used for experimenting and other random things.  For example:
    • One is connected to a 10 watt VV-898 and used for monitoring or listening to things like APRS, etc.
    • One is connected to an ID-880h and is mainly used to connect to my local hotspot and do some packet radio.
    • One is connected to the my local Open Repeater Project test system.
  • Below the 3 mag mount antennas, there is another grey box, this houses a raspberry pi that has a SDR dongle that is connected to the homemade ADSB antenna at the top.
  • You will also see a Ubiquity 5Ghz AC Sector Antenna pointing into the house, this is for testing the Ubiquity gear.  I will do a post at a later time on that project.

If you want to learn a little more about my Amateur Radio hobby, you can visit the Amateur Radio page under the Projects and Hobbies menu item or just click here.

If you are not an Amateur Radio operator I strongly suggest you check it out.  There is no Morse code requirement any more and the radios are dirt cheap.  The thing is, they will work when the Internet or Cell Phones don't.

Update:

Here is the picture from the other camera mounted on the tower, you will see my homemade ADSB antenna in the picture.