Digirig, APRS, Baofeng - Help Needed

Can anyone tell me if my setup is working correctly?

Let me begin by saying I’m very new to digital modes. In fact, this is my first attempt. I figured I would start by trying APRS.

I’ve got a Baofent UV-5R plugged into Digirig (with official cables) hooked up to my linux (ubuntu) box running direwolf. Direwolf can trigger the PTT and I can trigger the radio using wsjtx too.

At the configured time interval in Direwolf, there’s a very short keying of the mic and a short transmission. Honestly, it seems like it’s just keying the mic and then releasing it without transmitting but since I don’t know anything about digital modes I don’t really know. Here’s a brief video of what’s going on:



I agree APRS is a good first digital mode with the Baofeng HT.

This isn’t an answer to your question, but may help your troubleshooting.

A troubleshooting guide is here: Troubleshooting Digital Modes – digirig

The APRS handshake signals are short duration. If your outgoing signal reaches an APRS digipeater, the digipeated signal is likely to be received and heard by your transceiver. I do not hear a digipeated signal corresponding to your outgoing signal. Either a signal did not go out, or you are not in range of an APRS digipeater.

The radio you are holding is a monitor radio, right? Because I do not see any cable connected to a Digirig.

Is the transceiver antenna separated from the HT? That can cut down RFI if that is a problem.

Do you hear traffic on 144.390? That is a good first step.

Let us know how it goes.

73 Constrainted

Thanks Constrained. Yes, the radio in the video is a 2nd Baofeng that I have just to monitor the frequency.

I did follow the troubleshooting tips on the page you linked. I’m in the NE corner or RI and according to the maps on APRS.fi I should have plenty of APRS coverage.

I do periodically hear short bursts of transmissions on 144.390 that last longer then my transmission but since I don’t know what an APRS “conversation” sounds like I can’t say with any certainty what they are. They also don’t seem to be on any sort of schedule.

OK @kc1gze. That’s great you are hearing APRS traffic, and the 2nd Baofeng to monitor means you will reach success very quickly.

I do not know Direwolf well. There is a tool, soundmodem by uz7ho, which can decode the APRS traffic. You will see traffic like:

being decoded.

73 Constrainted

I just downloaded Soundmodem and got it setup. I’ll leave it running for the day, let’s see what happens

Great! Let us know what happens.

73 Constrainted

left it running all day, didn’t receive anything. I also had my monitor radio running all day and didn’t hear anything at all. Given where I am I think it’s strange that I’m not seeing ANY aprs traffic.

I ordered some connectors so I can hook up the baofeng to my discone antenna which hopefully arrive tomorrow so will repeat the test using that antenna.

Note: I’m currently using a Nagoya NA771 antenna

I’m glad you want to evaluate on another antenna. I have used a rollup J-pole type antenna and a 1/4 wave mag mount to get better results than with the antenna mounted to the radio. In my experience a person needs to hold the radio for those HT antennas to resonate at their best.

I’m not familiar with the Discone, but if it is higher and far from your HT, you will see improvement.

73 Constrainted

Hi and welcome to the forum. I run a Baofeng with the Digirig on packet which is the same mode as APRS. It doesn’t sound like you are transmitting AX.25 1200 baud packet (which is what APRS uses) in your video. I doubt that you will be able to decode APRS on your Baofeng HT unless you go sit on your roof, hi hi. You are on the right track. First decode some local signals on APRS or the local packet channel. Then see if you can transmit. Your monitor screen on the computer should show your transmission attempt, and the monitor HT should pick up the signature data burst of packet. Good luck.

Thanks. Any suggestions for software? I can run Windows, Linux, or Mac.

(I’d prefer Mac actually)

I decided to try Direwolf on Windows and I think I’ve got it transmitting but I’m still not seeing any responses. Does this video sound correct?

I still find it difficult to believe that there’s no APRS traffic in my area so over the next couple of days I’m going to try a few experiments:

  1. I’ll leave my transmitter running at home and drive around w/ another radio to see if I can receive the transmissions at various distances from my house.
  2. I need to run a few errands around Rhode Island this weekend so maybe I’ll take the radio and laptop with me and see what I can capture.
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Drove around town a little while ago, got about 5 miles away as the crow flies and could still hear the modem noise. Next experiment on Saturday.

Yes, that sounds like APRS traffic. That’s great progress! You are getting closer.

73 Constrainted

What antenna are you using? That will affect reception.

73 Constrainted

I’ve tried a Nagoya NA-771 and a Nagoya NA-771R.

I’m going to try doing receive only with my discone (Moonraker SkyScan) and might try using the rabbit ears that came with my SDR just to see what happens.

@kc1gze Have you considered a magmount antenna for the roof of your vehicle? You will need additional cable and a union connection for SO-239 and SMA, but in my experience, it is well worth it. You can also take that setup inside and mount the antenna on a metal baking sheet or some other sheet of conductive metal. In my experience, the 1/4 magmount will be much better than the stock Baofeng antenna.

@kc1gze If you have wire and an SO-239 (PL-239, I’m not sure which) bulkhead connector, you can build an excellent 1/4 wave groundplane antenna. You can mount it on a mast or hang it indoors:

Build it: 2 meter 1/4 wave ground plane antenna - KB9VBR Antennas (jpole-antenna.com)

Then there is always the rollup J-Pole antenna (N9TAX, Ed Fong, etc.)

73 Constrainted

I left everything (UV-5R with Moonraker SkyScan) running in receive only mode today and actually got one good capture from N3LEE-4 this morning! So now I know I can receive!!! I am going to try driving around tomorrow to see what happens. It’s quite possible that there just isn’t any APRS traffic where I live. I’ll probably start looking into other digital modes and see what sort of traffic I can receive, I just figured APRS would be an easy one to start with.

@Constrainted, regarding building an antenna: Would it be better to build it using a BNC connector or should I use the SO-239 then an adapter to SMA or BNC? If I start seeing success with this I’ll mount some antennas in the attic.

@kc1gze Congratulations on the success receiving N3LEE-4 traffic! Your persistance paid off.

Many presenters on youtube use BNCs. I started with an antenna terminated with PL-239, so that’s what I have parts for and use for projects. Do you belong to a club? They can advise you, too.

73 Constrainted

My experiment worked but was a bit disappointing. I drove around the state of RI, see the attached picture. Purple is the route I took on the way down, orange is the route home. I set direwolf to transmit every minute and only got one reception from KC1NWF and I only received one transmission all day (again from KC1NWF).

I’m comfortable saying things are working, but I’m disappointed that I didn’t receive more transmissions and that only one person saw mine. I guess people around here just don’t use APRS that much.

maybe I’ll move on to the next thing. Any suggestions? (At the moment, I’m limited to VHF/UHF)