[time-nuts] Chinese GPS jammer

[John Green]

Some time back, I posted my experiments with a cheap Chinese made GPS
jammer and Z3801. Since then, I have been able to check it on a
spectrum analyzer. It sweeps over about 30 MHz centered on GPS L1
frequency. Power looks like about -3 dbM. If I turn it on within 30
feet of the antenna, the Z3801 goes into holdover immediately.
Yesterday I tried it on my Garmin Nuvi and much to my surprise, the
Nuvi is totally immune. Even with the antenna of the jammer touching
the case of the Nuvi, it never lets on. I can only attribute this to
different signal processing methods. Next up, my HTC G1 phone GPS.