[aprssig] TinyTrak with D700 note from a few months back?

Keith VE7GDH ve7gdh at rac.ca
Wed Aug 15 19:10:00 CDT 2007

David KB3NAI wrote...

> I've recently "kind of" gotten my D700 working with a GPS receiver,
> but I'm not really satisfied with its transmitting performance, as opposed
> to my old HT/TinyTrak combo. I seem to recall some clever person
> posted a way of getting the TinyTrak to trigger transmission on the D700,
> but I can't find the copy of the digest with it. Can anyone point me in
> the right direction?

In spite of whatever faults it has, the D700 should actually "work". At risk
of opening the floodgates from other people that aren't satisfied with their
D700s, in what way are you not satisfied with yours?

What were you trying to do with the TT3? Did you just want to connect it to
the 6-pin mini DIN on the radio where you could otherwise connect an
external TNC as Andrew helpfully pointed out? You would move away from 
beaconing at a fixed rate and gain SmartBeaconing as well as getting rid of 
the obscenely long TXDelay by using the TT3, but you would lose the 
advantage of receiving position reports or messages from other stations.

To do this, make up a cable to connect the TT3 to the "data port" and set 
the radio to "packet" mode instead of "APRS" mode. The TT3 would then be 
running the show. The pin-out of the data port is shown on page 2 of the 
"specialized" manual. The pins you would need to connect to are...

1 audio in to the D700
2 ground
3 "packet standby" I think you can read that to mean PTT
5 audio out... so the TT3 can tell when a signal is present OR
6 squelch... you could use the "COS" method to tell the TT3
                 when to hold off transmitting instead of the audio
                  by connecting it to the TT3 "carrier detect"

Scott N1VG has 6-pin mini DIN patch cables. Just cut the connector off one
end and connect a DB9 to go into the TT3. Follow the link from www.n1vg.net
or go straight to
(or sacrifice an old PS2 mouse and hack the tail off)

Or were you intending to use the TT3 connected to the PTT so it could
trigger a MIC-E burst when you unkeyed on an APRS equipped repeater?

73 es cul - Keith VE7GDH
"I may be lost, but I know exactly where I am!"

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