Signal Not Being Received

I have a head scratcher, guys.

I installed a Tiny Trak in my RV-9A with appropriately shortened (to 2m length) aviation antenna on the belly of the craft. Before installation I put the setup in my car, and at the same time set up a UIView receiving station at my house. Everything worked fine, and until my car got out of range of my 40ft dualband antenna at the house, it showed and tracked the Tiny Trak's position in my car.

Anyway, I installed the thing in my plane. From installation time to just prior to our first flight the 2m radio on my receiving station went to ****, so my receiver was down. I thought "no big deal" because equidistant from the airport as my house but in the opposite direction is K5VAS's receiving station.

So, several weeks ago we had our first flight (YAHOOOO!). However, no tracking. Nothing on the map at all.

Thinking there was a problem with the transmitter, I tuned the 706MKIIG in my car to 144.39 when one of my partners was flying and I was at the airport, and sure enough, there was the signal, loud and clear, full scale.

Well, pulling up Google APRS I noticed that the receiving station I THOUGHT was on the air, K5VAS, had not been receiving for quite some time.

Aha! Problem solved. Neither my station nor K5VAS receiving. So, I ordered another 2m radio and replaced the broken one at my own station. Had it up and running last night on UIView. Showed to be receiving and transmitting properly.

Flew 1/2 hour this morning. Drove like **** to my office to pull up Google APRS knowing full well that (1) the Tiny Trak in my plane was putting out a signal and (2) my receiving station was working.

Nada. Nothing on the map. Sooo, what the **** do I do? I know that the radio and antenna at my station are working properly. Home station is an an Icom ID-880D, and is interfaced to a KPC-3 with the appropriate BuxComm cable. Just before hooking up the KPC-3, I had a QSO on a local repeater. Hooked BuxComm cable to KPC-3, fired up UIView, connected to the internet, and watched it transmit over the radio. Also heard some weak packet signals when tuned on 144.39.

Relatively certain Tiny Trak in the plane is working right due to the aforementioned receipt of packet signals from the craft in my car.

Let's assume that there is a problem in the coax cable from Tiny Trak to the antenna--once I was more than 100 feet from the plane I shouldn't be able to receive it at all, right? So that's not the problem--he was airborne and I was receiving the signal several miles before I got bored and turned it off.

What if, for some reason, the GPS antenna is either not working or the cable is broken or somehow got disconnected? Would the 2m transmitter still put out a signal? If so, would it be kinda "blank," meaning no data such that it would not show up on Google APRS?

Just so you know, I contacted the Tiny Trak people before installation and they told me that there were only 3 wires from the GPS antenna to the 2m transmitter. I told them I had to run it from my glare shield and down behind the panel. They advised to simply cut off the connector and told me which wires to resolder onto another connector so I didn't have to cut a 1/2 inch hole in my glare shield.

If the 2m transmitter still works but I miswired the damned connector, would this problem result--that is, 2m signals but no display on Google APRS?

Help me trouble shoot here guys.

Maybe Allen Lord will chime in and either confirm or invalidate the following points.

If you have "Send only valid" checked in the tracker config, it will only transmit when it has a good data stream from the GPS.

If that option isn't checked and the GPS isn't sending valid lat/long data, beacons will still be transmitted but you may end up in the Indian Ocean or some other obscure location.

Sounds like you need to confirm good GPS data. Keep working with it, it is worth the effort.

Sam Buchanan said:

Maybe Allen Lord will chime in and either confirm or invalidate the following points.

If you have "Send only valid" checked in the tracker config, it will only transmit when it has a good data stream from the GPS.

If that option isn't checked and the GPS isn't sending valid lat/long data, beacons will still be transmitted but you may end up in the Indian Ocean or some other obscure location.

Sounds like you need to confirm good GPS data. Keep working with it, it is worth the effort.

Click to expand...

I am finding your post a little hard to follow, so let me ask a few questions: 1) Does the green GPS LED on the TT3 light solidly at some point? If your TT3 is understanding your GPS, they LED should light solidly when the GPS has acquired a signal.

2) Is this a TT3 and an additional radio or a Micro-Trak? Do I understand correctly that you can receive the signal loud clear, but not hitting the web? I suggest downloading a free copy of AGWPE and connecting it to your receiver to validate that you are sending decodable packets. It may be something as minor ( and common) as over-modulating, a frequent problem when you set a TT3 and a hand-held "by ear" . Your transmissions should be a little "softer" then you would set them intuitively.

Allen
VHS/Byonics

Just an observation (since I'm debugging an APRS setup currently) - if you do not have "send valid" in your configuration, aprs.fi will log the raw packets but not show them on a map. You can try to look up your SSID and then look at "info" and then look at the raw data.

Additionally, if you know any of the local HAMs doing APRS, one of them may have either the TH-D72A or the VX-8GR. These are handy for diagnostics.

From Sam's writeups, I arrived at the following settings:
Callsign - <Aircraft N Number>
Text - <FCC License Number>
Symbol - ' (change to single apostrophe from right bracket)
Auto TXD - 300
Manual TXD - 133
Manual TX Rate - 90
Quiet Time - 526
Only Send Valid - Uncheck the box
MIC-E Message Change - Enroute
Smart Beaconing - Enable
Smart Beaconing Slow Rate - 60
Smart Beaconing Fast Speed - 65
Smart Beaconing - Fast Rate - 60
Path - WIDE2-1

Allen was great with support.

Pete Howell (actually his daughter) supplied the antenna.

All stuffed in the wingtip and it has worked great.

Dan

Thanks for all the input. My problem was something VERY simple---I velcroed the GPS antenna to the glare shield. Cut off teh DB9 so I could route the cable through a hole in the glareshield, and resoldered a db9 connector per instructions from Byonics.

I originally thought I had soldered it wrong. So I began crawling around under the panel (I HATE THAT) and found that my DB9 male connector from the GPS antenna had come loose from teh female DB9 leading from the transceiver. SO, two drops of loctite on the plugs and once 200 feet offt eh ground and everything worked as advertised.

dahugo