Garmin 2820, APRS, and Yaesu VX-8R

[SAMSAR]

The new Yaesu VX-8R that is scheduled for release later this month will have APRS and Bluetooth capabilities. There is still a ton of speculation on the handheld itself and what it can and can't do so I am fine with waiting for the initial user reports on Yahoo Groups.

 

My question is really about my Garmin 2820 and whether there is a way to interface it with any APRS radio? If so, how is this being done?

 

I'd also be interested in knowing whether anyone has interfaced their Autocom PTT with a Yaesu VX-7R? If so, how is this being done?

 

Thanks!

 

Paul

 

 

[WestTX RT]

Looks like one cool little rig.

 

On the 2820, I don't think it has the NEMA output you'll need to do APRS. Don't take my word, you might do some more research.

 

I ran with a VX-7 for guite a while set up with the Autocom. You just need the PTT and there is a special VX-7 Autocom cable. I RAM mounted the HT on the left handlebar with a mirror post mount. It did well with the rubber duck, but when I mounted a dual band Maldol AX-95 on a Toolman mount on the luggage rack and ran a cable back to it, it was outstanding. I'm running an FTM-10 now.

[SageRider]

From what I've read, the VX-8R gains it's APRS capabilities by adding a GPS module to the radio as opposed to receiving a signal from a different device such as a Garmin GPS.

 

The setup I was runnning, A Kenwood D-700A and a Garmin 276c or 376c utilized the GPS NMEA output capability through the serial port (accessible via the main power cable) fed to the Kenwood.

If the Garmin 2820 is capable of an NMEA output, then the D700A can handle it. Kenwood used to have a handheld which could also accept an NMEA feed for APRS, but it appears to have been discontinued. There are other optins available but I am not familiar with them (Tiny-Track, etc...)

 

I have interfaced a Yaesu VX-5R to the Autocom. Since I use bike power to charge the battery in the radio, complete isolation is necessary to prevent noise / ground loop issues.

1:1 audio transformers for the mic input as well as the audio output and optocoupler isolation for the PTT. At least on my VX-5R, PTT is activated by allowing a small DC current to flow from the MIC input to the Radio Ground. I am running a 27K resistor through the output side of the photocoupler to the radio ground and it is working for me, but I have not yet optimized resistance value to find out how high it can go.

With the Autocom Bike to Bike Comm cable:

The Autocom PTT output is a low impedance path to ground. If using the PTT switch module, the 3 positions allow:

1 - the Autocom to control bringing the ouput low (VOX mode).

2 - PTT button to control bringing the output low (PTT mode).

3 - Always on. Output is held low.

 

I am using the Autocom +9V out through an appropriate resistor (1KOhm for me) to power the input side of the optocoupler with the Autocom PTT output providing the ground.