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TeleGPS antenna length

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watermelonman

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Has anyone out there got a TeleGPS unit handy today? I would love to get an exact measurement of the antenna length.

I am at a multi day launch, and I ripped mine off mid flight. Thankfully I have a battery soldering iron and the proper wire, but need to know the length. Thanks!
 

mpitfield

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6.5", that is measured from the edge of the PCB to the end of the wire.
 

ksaves2

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Post how the flight goes. I'd be interested if you're using a Dongle, Tele-BT or the APRS side only. Running Altus-Droid with cached maps?

The Altus Metrum products are the only ones that concurrently send coded information digitally to their receivers AND an APRS packet so one who simply wants
to track, can do so with an APRS ground station only. I can fire up a Kenwood D-72A I have interfaced to a Garmin 60Cs(X) and use this same ground station with Beeline GPS trackers. The Tele-GPS is the smallest rocketry purposed based GPS tracker out there so if a Ham flier needs something smaller than a Beeline, it can be used with their same receiver hardware and they wouldn't have to buy anything else. Kurt
 

keithp

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Has anyone out there got a TeleGPS unit handy today? I would love to get an exact measurement of the antenna length.
Sorry, lost internets over the weekend due to a storm! It's a 1/4 wave whip using the PCB as the 'ground plane'. With that, the speed of light, frequency and velocity factor of a solid copper conductor, you can compute the length on your own:

Frequency: 435MHz
Speed of light: 3 * 10⁸m/s
Velocity factor: 0.95
Antenna design: 1/4 wave

speed of light
----------------- * velocity factor * 1/4 = 0.164m or 16.4cm or 6.5 inches
frequency
 
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