Monthly Archives: August 2008

APRS Troubles with my RTrack…Solutions?

Posted on by
Reply

I had received my Rtrack APRS tracker a few months ago, and it seemed to operate properly but was rarely picked up by local digis or igates.  After finally getting some more time to work with it, I played with the configuration a bit, adjusted antennas and such, but now it absolutely refuses to get picked up or digipeated at all!

The odd thing about it was that my Kenwood TH-D7 was picking up the packets with no problem at all.  Ideas I had for troubleshooting included:

  • Increasing the delay between keying up and transmitting the packet in case the start of the packet was getting clipped
  • Turning the Rtrack volume down in case it was too hot
  • Trying various antennas
  • Trying more power by adding my 35 Watt amplifier to the system
  • Changing my call from KI6ESH-3 (used for digipeaters) to an SSID of 9, the standard for mobiles (thinking maybe the digis were ignoring other digis)
  • Checking input voltages to make sure they were high enough to drive the transmitter properly
  • Going to a nearby mountain top to see if I simply wasn’t getting a good path out.  My TH-D7 even on low power got digipeated immediately, but nothing from the Rtrack.

None of those seemed to have any effect.  I went ahead and captured a packet from the Rtrack on my Kenwood to take a closer look at what it was sending:

KI6ESH-3>APOTC1,WIDE1-1,WIDE2-1:/170607h3703.36N/12201.85W>000/000/A=000439 11.7
VRTrak V1.7

Set up in it’s “simplest” configuration and with the GPS data turned off, this is what the packet looks like:

KI6ESH-3>APOTC1,WIDE1-1,WIDE2-1:>

So the packets look fine there… I don’t see any reasons they wouldn’t get digipeated or igated properly.

When listening to the packets on another radio, I noticed they really
seem to “sound” different to me, not sure if this makes any sense, but
I recorded the audio of one RTrack packet and the second packet is
from my TH-D7.

Is it possible for anyone to decode the packets from the MP3 and see
if the first packet does appear to be valid?  Here is the audio file:

http://ki6esh.com/rtrack_and_thd7.mp3

Are there any troubleshooting ideas I could try to make this start
working again?  I am going on a road trip this week and would love to
track the journey to Black Rock City.

I’ve tried various antennas (rubber duck, small mag mount, large mag mount, large mag mount with a 35 watt inline amplifier, took it flying over cities at low altitude where coverage should have been great, etc)

Here is a copy of my configuration profile in case I have something
set up incorrectly there:

Any help in getting this to work would be greatly appreciated.
Otherwise I’ll get it shipped back for additional troubleshooting help.