Standalone APRS mobile system using a Maxtrac mobile radio

snare

Adventurer
Been thinking about a standalone APRS system in my truck that doesnt use a handheld.

So far I am considering a MobilinkD (bluetoothed to the tablet/phone used for navigation with Gaia), and an old VHF Motorola Maxtrac.

The MobilinkD now has the capability of turning on (and off) automatically as it senses power through a USB charging cable. So, I am thinking keyed power> switch> relay> power for radio and MobilinkD, so the whole thing will turn on with the igntion , or it can manually be turned off from up in the driver's seat.

Anyone use a Maxtrac for this purpose? Another inexpensive /surplus mobile?
TNC other than MobilinkD?

Looks like i can get an adapter from Argent (https://www.argentdata.com/catalog/product_info.php?products_id=169&osCsid=u2grr52jp8oljgr0d5pa7pto16) that will allow use of a mini DIN cable between it and the MobilinkD.

(and now to just get Gaia to integrate APRS / APRSdroid like Backcountry Navigator Pro now has in beta)
 
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prerunner1982

Adventurer
I run a Mobilinkd connected to a Yaesu FTM-3100R and it works well.
When I move it over to the Jeep I am building I too will wire it similar to your description above.
I had go make my own cable to plug into the mic jack and the external speaker jack of the radio but it was not hard at all, Mobilinkd sells the TRRS plugs on their website. I started out trying to use a cheap HT with an external antenna for APRS but got tired of jacking with it, poor receive, and barely making it to the nearest digipeater (20+ miles away). Works much better now and can work APRS packet through the ISS with the same mobile set up.
Sorry I can help you specifically with the Maxtrac or Gaia integration.
 

snare

Adventurer
cool. yeah. i think it is definitely doable with the maxtrac. And as for gaia, i think we need more people requesting the APRS integration. What is ISS?
 

prerunner1982

Adventurer
cool. yeah. i think it is definitely doable with the maxtrac. And as for gaia, i think we need more people requesting the APRS integration. What is ISS?
ISS = International Space Station which has a digipeater on board.
 
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snare

Adventurer
I've used an Baofeng HT plugged directly into an old android phone running aprsdroid and it worked ok, but didnt reach many digipeaters and t has an issue with not picking up all packets due to it's speed.

I am thinking this maxtrac will be a rugged, simple solution with a mag mount antenna i already have. And, I can easily unplug the mobilinkD and use it with my phone or an HT even if i am away from the truck.
 

prerunner1982

Adventurer
I've used an Baofeng HT plugged directly into an old android phone running aprsdroid and it worked ok, but didnt reach many digipeaters and t has an issue with not picking up all packets due to it's speed.
Same HT and same problem I had.
 

camp4x4

Adventurer
Been thinking about a standalone APRS system in my truck that doesnt use a handheld.

So far I am considering a MobilinkD (bluetoothed to the tablet/phone used for navigation with Gaia), and an old VHF Motorola Maxtrac.

The MobilinkD now has the capability of turning on (and off) automatically as it senses power through a USB charging cable. So, I am thinking keyed power> switch> relay> power for radio and MobilinkD, so the whole thing will turn on with the igntion , or it can manually be turned off from up in the driver's seat.

Anyone use a Maxtrac for this purpose? Another inexpensive /surplus mobile?
TNC other than MobilinkD?

Looks like i can get an adapter from Argent (https://www.argentdata.com/catalog/product_info.php?products_id=169&osCsid=u2grr52jp8oljgr0d5pa7pto16) that will allow use of a mini DIN cable between it and the MobilinkD.

(and now to just get Gaia to integrate APRS / APRSdroid like Backcountry Navigator Pro now has in beta)
Interesting... certainly looks like you have to be very careful about with GM300/Maxtrac you're buying on ebay. Looks like some have the 5-pin accessory connector, others the 16-pin. Otherwise seems like a perfectly good radio for the job.

You may have already looked into this, but MobilinkD suggests this guy for custom cables. He could probably do one that's straight into the existing accessory connector rather than having to get that Argent unit and then a cable. Just a thought.
 

snare

Adventurer
Interesting... certainly looks like you have to be very careful about with GM300/Maxtrac you're buying on ebay. Looks like some have the 5-pin accessory connector, others the 16-pin. Otherwise seems like a perfectly good radio for the job.

You may have already looked into this, but MobilinkD suggests this guy for custom cables. He could probably do one that's straight into the existing accessory connector rather than having to get that Argent unit and then a cable. Just a thought.
yep. will look into that cable guy. have contacted him via ebay.
 
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snare

Adventurer
ok, after a little research (still waiting on replies from maxtrac seller and the hammadeparts guys) I see that hammadeparts sells an 8 pin RJ45 > TRRS 3.5 cable that looks like it could be used to connect to the mobilinkD on a maxtrac with a 5 pin accessory connector. essentially just using the mic connector on the radio rather than the accessory connector.

https://www.ebay.com/itm/Motorola-MAXTRAC-RADIUS-RJ45-8-pin-Mic-Plug-to-3-5-TRRS-Plug-MobilinkD/201379482392?hash=item2ee3270b18:g:FSoAAOSwLVZVkN4z


Some info on the Maxtrac/300 radios. Scroll down to Interface Articles and there is a pin out article for the connectors in reference to their use for APRS
http://www.repeater-builder.com/motorola/maxtrac/maxtrac-index.html
 

camp4x4

Adventurer
ok, after a little research (still waiting on replies from maxtrac seller and the hammadeparts guys) I see that hammadeparts sells an 8 pin RJ45 > TRRS 3.5 cable that looks like it could be used to connect to the mobilinkD on a maxtrac with a 5 pin accessory connector. essentially just using the mic connector on the radio rather than the accessory connector.

https://www.ebay.com/itm/Motorola-MAXTRAC-RADIUS-RJ45-8-pin-Mic-Plug-to-3-5-TRRS-Plug-MobilinkD/201379482392?hash=item2ee3270b18:g:FSoAAOSwLVZVkN4z


Some info on the Maxtrac/300 radios. Scroll down to Interface Articles and there is a pin out article for the connectors in reference to their use for APRS
http://www.repeater-builder.com/motorola/maxtrac/maxtrac-index.html
Ah yeah, totally missed that. I'm 99.9% he'll come back and say that's exactly what you need. Since you're powering the MobilinkD separately all you need is Rx, Tx, and PTT which the mic connector has. And since you won't actually be using the mic... GTG. :)

I'm actually looking at building a fill-in digipeater with a Raspberry Pi, TNC-Pi (TNC-X) and some radio.. kinda got me looking at the GM300's now... thx! ;)
 

snare

Adventurer
I am hearing the radio will program down the 144.39 without issue.

Can you think of any other channels i should have programed in, since I wont be programming this myself, most likely?

I am thinking the simplex call frequency, but not sure what else would be good to have in there (just in case).
 

snare

Adventurer
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camp4x4

Adventurer
Ok, I read that the ISS APRS / packet frequency is 145.825.

Also, I read that in some extra urban areas 144.99 is used and then digipeated to 144.39. 144.99 was proposed as an alternate input channel by Bob Bruninga. http://www.aprs.org/APRS14499.txt and http://www.aprs.org/alt-99digis.txt and http://www.aprs.org/newN/altchannel.txt

http://info.aprs.net/index.php?title=Frequencies

This says 144.35 is an alternate input in western Washigton. I wonder if this is accurate.
The one thing I would ask is: is this the only radio in the vehicle or a secondary run strictly for APRS?

If secondary then I think you have the channels covered.

If primary... then I'm curious what other uses you'd have for it and suggest you need to re-think using the RJ45 connector for the TNC and instead use the accessory port so you can keep the mic on. One benefit of this would be the ability to use VoiceAlert with CTCSS 100. http://www.aprs.org/VoiceAlert3.html
 
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