[time-nuts] Re: Testing a GPS mag mount antenna

[Tom Holmes]

BTW, Skipp,  there is a slim chance that a non-amplified antenna is a DC short, so wise to check that before you try to power
it up from a PS or a receiver..

Tom Holmes, N8ZM

-----Original Message-----
From: Dana Whitlow <k8yumdoober at gmail.com> 
Sent: Saturday, August 21, 2021 12:13 PM
To: Discussion of precise time and frequency measurement <time-nuts at lists.febo.com>
Subject: [time-nuts] Re: Testing a GPS mag mount antenna

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 <n8fgv at usa.net> 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 -- time-nuts at lists.febo.com -- To unsubscribe send
> an email to time-nuts-leave at lists.febo.com
> To unsubscribe, go to and follow the instructions there.
>
_______________________________________________
time-nuts mailing list -- time-nuts at lists.febo.com -- To unsubscribe send an email to time-nuts-leave at lists.febo.com
To unsubscribe, go to and follow the instructions there.