It may or may not tell you what's wrong but a quick check of the Thunderbolt would be to put a tee in series with the antenna and see if the unit is supplying +5 volts under load to the antenna.You have verified that the antenna works with a second unit so you can rule that out. Where you are getting some data from Lady Heather showing it picks up at least 1 satellite I suspect the +5 Vdc power supply that supplies the logic is functioning properly or you'd probably see no data. The +12 Vdc mainly supplies the oscillator so if that's working properly, the +12 is probably ok, It may well be a component in the receiver section on the Thunderbolt board.
The Thunderbolt receiver board I looked at had a Macom AM50002 amplifier ( http://cs.utsource.net/goods_files/pdf/71/71500_MACOM_AM500002.pdf ) located on the top side of the board directly behind the antenna connector. The bottom side of the board has D1, Q1, and R1 directly behind the 1PPS connector and they apparently supply the +5 to power the antenna. Those two areas would be likely suspects. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.