I used to test cheap GPS antennas with the network analyzer, using a bias-tee to feed 5V power to the antenna and to avoid damaging the VNA RF input (even if the RF input is 50V tolerant).
On Sat, Aug 21, 2021 at 6:14 PM Dana Whitlow <[email protected]> wrote: > > I love Dan's idea, with one caveat. The transmission through a > powered-down LNA > is an unknown, probably even to the manufacturer. Thus comparing output > signal > levels with power on or off is pretty meaningless. > > But his test with power on should be a great way to get some clue that the > antenna > is working, and is clearly simpler to perform than what I was suggesting > yesterday. > > Dana > > On Sat, Aug 21, 2021 at 9:49 AM Daniel Schultz <[email protected]> wrote: > > > > Should I be able to "see something" on or around the GPS frequency other > > > than what I suspect will be something visual looking like a noise/pulse > > > source/signal? > > > > You could try sweeping a harmonic from a signal generator across the > > antenna > > passband, this would be visible on the spectrum analyzer and might give > > you an > > idea if the preamp is amplifying or attenuating the signal. Try it with the > > preamp power on and off. If your signal generator does not generate > > sufficient > > harmonics at L band you can feed the signal into an overdriven MMIC > > amplifier. > > > > Dan Schultz N8FGV > > _______________________________________________ > > time-nuts mailing list -- [email protected] -- To unsubscribe send > > an email to [email protected] > > To unsubscribe, go to and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send an > email to [email protected] > To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
