Featherweight GPS antenna re-mounting

[Chad]

I need to make a very short ebay but it needs to include a Featherweight GPS. What options are there for moving the antenna? Is it as simple as using one of those pigtails to move the antenna location? ( I remember antennas have some weirdness when it comes to moving them around from my circuits class but that was like 25 years ago... )

example of what i mean when i say "pigtail"
https://www.amazon.com/RG316-Female...a+pigtail+femail+to+mail,industrial,82&sr=1-4
edit: if you haven't seen it here's what the tracker looks like
https://www.featherweightaltimeters.com/uploads/1/0/9/5/109510427/gps_tracker_manual_2021oct25.pdf

 

[user 30299]

The cable in the Amazon link is fine. I've had to use longer ones to move the antenna to a bulkhead.

The picture shows the cable going from the T3 tracker to the bulkhead on the avionics bay.



Just don't bring your antenna back around so that it's sitting overtop some of your electronics.

 

[AllDigital]

Using an SMA coax extension should be ok, but you might get some performance drop depending on the antenna design. The small whip antennas are usually just a single plane/pole of the antenna, while the board provides the ground plane. The design might assume that the antenna and the ground plane are connected for optimal performance.
I would use the extension, but then ground test it inside the avbay from a distance you expect it to work. You could also do a simple ground test with and without extension to see the difference.

One note on the coax extensions, lay them out with well rounded turns. No hard 90 degree turns — RF doesn’t like 90 degree turns in coax.

 

[Adrian A]

There is a lot of margin in the LoRa link, so the LoRa antenna configuration is really forgiving if you're going under, say, 50 kft. For example, in the above picture another option would be to just scoot the tracker back a little, take the plastic radome off of the stubby antenna and bend it 90 degrees to fit. One of the longest-range examples I know of with the Featherweight tracker, the 137,000 foot altitude shot a few years ago, was a tracker with the stubby antenna duck-taped to a 1-4" threaded rod that went through the center of the nosecone.