Christmas 2010 was over, winter was getting duller and I was wandering aimlessly around Frostfest. Truth be told, I had no idea what most of the junk – whoops, I mean “collectible equipment”, even was, because I had only recently joined the hobby.
When I received my “ticket” I did my “research”, talked to fellow HAMs, and finally decided to purchase a mobile rig which was D-STAR “enabled” – an ICOM ID-880H. I’m not writing this article on the pros or cons of D-STAR. I’m just here to share my experience about the DVAP Dongle (the RED dongle as most folks might know it).
My experience at the FrostFest had taught me a valuable lesson; I needed to get involved in ANY particular part of HAM radio and dive into it deeply. I remain convinced that is the only way that I am able to understand anything – I have to focus almost all my energy towards that single goal. With that as my mindset, I decided that since I had the gear; I’d jump into D-STAR and start “figuring it out.”
I got involved with the data side immediately, started using D-RATS for data based “text chatting” and file transfer. I found the ICOM serial data implementation protocol somewhat inconsistent and troublesome. If anyone remembers a serial terminal data transfer protocol called Kermit – welcome to my world. I felt like I was a kid again, back in 1982! The serial interface is NOT 8-bit friendly, oh no – ICOM used ASCII flow control as part of the data stream Yuck. The only really effective way to use the serial interface was with a 7-bit protocol – ah la Kermit! Memories – wow, and back in 1990 I thought I’d never use Kermit again – who knew?!?!
With that little bit of history and the data issues “figured out”, I was a little more gun shy of what D-STAR technology brought to the party. In short, I wasn’t particularly eager to try more D-STAR technology right away, perhaps I’d learned enough in that area for a while. That was, until I realized the beauty of the D-STAR networking model. For those of you that are familiar with IP networking, in the D-STAR world your callsign (ICOM calls this the CS field/parameter) is just like a “system/computer hostname”. That means that your callsign is assigned an IP address within the D-STAR network – interesting huh?
Even more interesting is that you can use a callsign as a routing method. For example, if I wanted to talk with El Presidente, Win Grant (WA4SSG), all I needed to do is put his callsign into my radio, hit the PTT and WHEREVER Win last key’d up, my transmission would show up there! If Win used his HT in Las Vegas, my call would automatically be routed to the Las Vegas repeater. If I was using IRLP, I would have to know where Win was, know if there was a local IRLP node located near him (and me!), dial up/link the destination repeater to the local repeater and then call CQ. The D-STAR networking model did all that work for me, automatically, just by using his callsign. That was really interesting!
Unfortunately, I also had an “issue” – the RARC D-STAR gateway wasn’t online and working. I have in-laws that live in the DC (Alexandria) area and periodically travel up that way for visits. During one of those visits, I tried to bring up a reflector (which is just a gateway computer that links a bunch of repeaters together) and wasn’t able to communicate. Ok, I guess I had more “learnin” to do – and “learnin” I did…
Here are some of the important tasks you need to complete before you can communicate (talk, text, transfer files, etc.) within the D-STAR network:
- You must register your callsign with a D-STAR gateway. RARC should be able to help you with this in the next few months or so. Until then, our Alexandria friends have the closest gateway registration server:
- You must configure your transceiver with the Repeater settings:
a.Note: (the — are spaces, you should have 3 spaces with each setting!)
b.If you’re using the 2m repeater: The RPT1 setting MUST be “W4FJ—C”
c.If you’re using the 70cm repeater: The RPT1 setting MUST be “W4FJ—B”
d.The RPT2 setting MUST be “W4FJ—G”
- Who do you want to communicate with?
a.If you wish to communicate with a particular ham, El Presidente, for example, you would configure the UR to be “WA4SSG”
b.If you just wanted to give a general CQ call, configure the UR to be “CQCQCQ”
- Press the PTT and start chatting!
Note: We’ll have a discussion at a later date around how to link the RARC repeaters to remote reflectors/repeaters.
My home is just a little too far away for my HT to bring up the 2m/70cm D-STAR repeaters, so I had just the right problem that the DVAP Dongle would fix for me – the DVAP Dongle will let me (eventually) connect from my QTH with my HT to the RARC D-STAR repeaters! Order with HRO placed and the next day, the shiny little RED DVAP Dongle appeared on my doorstep.
I have nothing but good things to say about the product, the website, and the technical documentation! The install documentation was VERY well written, easy to understand and most of all – ACCURATE!
I downloaded the software from the website and following the directions, installed the USB driver, plugged the DVAP Dongle into my laptop, ran the DVAPTool and established the connection between my HT and the DVAP Dongle. Wow – it just worked! Amazing! Robin Cutshaw (AA4RC) has done just a great job with it.
There are a number of interesting things that you can do with the DVAP: Connect to repeaters/reflectors (kinda the main reason to purchase the DVAP Dongle!); perform echo tests; check DVAP Dongle status; even write your own interface to parse/read the data stream in real time!
I connected my DVAP Dongle and established a connection to the Northern Virginia Reflector (REF025B) and gave a CQ. It worked! I received a return call from a gentleman driving around Springfield – there was a little bit of the R2D2 noise (kinda noise that you get from packet loss, not quite like background static – more like garbley tones) – but I think it was from him driving around, not from lost internet packets. When a D-STAR transceiver determines there are data packets being missed or dropped, the display will actually inform you of the data loss condition.
I have recently performed some testing around the Internet speed needed for the DVAP Dongle. It seems that the DVAP Dongle uses about 7Kbytes per second of data – the device is a simplex device, so it needs the 7KB either sending or receiving – but NOT at the same time. A 56k modem has the potential to meet the minimum network bandwidth requirements for the DVAP Dongle – though I would suspect it would be barely tolerable. The good news is that almost every public Wi-Fi access point, Starbucks, and hotel will provide at least 7KB! It is a very achievable level – you should expect the DVAP Dongle to work pretty much wherever you find internet access.
I have tried the DVAP Dongle on a variety of laptops, Windows XP, Vista, Windows 7, Windows 7 – 64 bits – I have not tried it on Linux. The speed of the processor and disk drive, the amount of RAM, and the age of the laptop do not impact the performance of the DVAP Dongle. Once the application, which is very small and does NOT require an installation program, gets up and running – it takes almost no system resources and provides efficient repeater operation. Each of the Windows Firewall programs I’ve tried has allowed the DVAP Dongle to work properly with no custom configuration. You do not have to configure your network router and you do not have to open any special ports. In summary, you plug it in, start the application, connect to your repeater/reflector and start communicating. There are few things in life this simple!
A number of people have asked Robin about using external antennas; I guess there is a repeater owner somewhere in all of us… Robin clearly states that it’s possible, but is not recommended. His example is for someone who wants to walk their dog around their neighborhood within a ½ mile – perhaps it’s doable with an external antenna, your mileage may vary! Robin also suggests that the DVAP Dongle does not perform the necessary functions to perform as a repeater – functions such as self-identification every 10 minutes. It is important to remember what the purpose of this device is; to get you onto the D-STAR network if you are not able to connect through your local repeater!
The tolerance for data latency and the error correction built into the D-STAR data and voice protocol allows for very efficient and reliable data transfer. The best example of this technology occurred during the recent Boy Scout Jamboree Over the Air (JOTA). Win brought his Verizon Wireless MiFi and I connected my laptop to the Wi-Fi – we had internet access. I started up my DVAP Dongle software. Again, it worked as advertised! We connected to the JOTA reflector that had been set up for this special event and made contacts to Europe, South America, and New Zealand – the Scout were very excited! (Oh, and so was I!)
More information on the DVAP Dongle can be found at http://www.dvapdongle.com.