TXE36

I've had my second hand TM for a little over a year now. It came with the car and is one of the early units. I'm noticing in my data occasional glitches that appear to be GPS position errors where I appear to get samples well outside the race track perimeter fence.

The GPS antenna is magnetically attached to the trunk lid just behind the rear window. The car is a 1997 E36 M3.

Is this something I have to live with or can something be done to improve the GPS signal reception?

One other thing I noticed is that very infrequently it stays stuck in "Looking for GPS signal". Power cycling will clear this and it will acquire the GPS signal very quickly after coming back on. This has happened maybe once or twice in a year and a half with a lot of use, so it's very intermittent.

-Mike

ProCoach

Replace the antenna. That's a regular service item, since it's being fed 3.3 volts all the time. The coil is coming apart inside. You can buy the cheap version for $33 or I can sell you the serious version for $99, which is pretty awesome!

Matt Romanowski

Traqmate considers the GPS antenna a regular service item?

TXE36

Thanks Peter! I may actually have a spare from by homebrew data system that is now dormant. I think the GPS antenna is the same. Development stopped when VR sold me his TraqMate and threw in the race car plus a trailer.

Does the antenna make that much of a difference? I would really hate for a moment of brilliance to be lost due to a buggy data system.

-Mike

ProCoach

Test is that your lat and long g are fine but your speeds intermittently go bonkers and the track map is not correct (losing, then reacquiring signal). Be careful in antenna selection. It needs to be the right impedance, voltage and sensitivity. I don't know what that is for the TM, but I stock antennas because many of these systems are now more than ten years old. I like to replace them every three to five years. Glenn said that is the first thing (and usually only component) that fails. It starts intermittently, then gets more frequent. Cheap insurance.

ProCoach

Racelogic, MoTeC (the L5 and L10 light grade versions) and Traqmate all sell a fair number of antennas. While many are damaged by pinching and cutting, the internal coil insulation can break down, causing shorts or opens. I've had this happen on about 3% of the EVO4's I have sold since 2009 and I stock replacement antennas for this repair at the track. I've had about the same percentage of failures on the SC GPS-05B and the GPS-05 for the dashes. Joe and I often compare notes and these failures, while rare, are not unusual.

Matt Romanowski

Most of the GPS antenna problems I've seen are from damaged cables. I have had a few GPS-05B have problems with the chipset, but AiM has been able to fix them.

I don't see any GPS-05 failures.

ProCoach

Can't explain that, but I (and Joe, I think) have had more GPS-05's that stopped working than GPS-05B's that were DOA or intermittent. Could be the relative age of the install?

It's rare, but when I see no speed or erratic track mapping or lap timing, the first place I go is the antenna...

The TM antenna advice is for troubleshooting and preventative maintenance, and as one of the first GPS based systems, a lot of them (the antennas) are aging out. It's a cheap fix and cheap insurance. This is true for R-K and Race Technology, as well.