TangoWhiskey
Touchdown! Greaser!
Impressive problem, clearly shown by your video. What was the fix? New antenna?
GPS outage or system problem?
- Thread starter azure
- Start date
jsnapp
Pre-Flight
Yes....the fix was a new antenna. The original antenna was 6 months old. The new antenna has been in for several years now without any problems.
denverpilot
Tied Down
Technically, aren't their antennas amplified/active devices? So really the "antenna" may not be broken so much as the active amplifier components packaged inside the "antenna"?
Not familiar with their exact antenna, but am familiar with others that would be similar in concept... Probably bad filters on the amplifier components...
denverpilot
Tied Down
Or bad power input protection for the inevitable spikes of connecting/disconnecting the antenna assembly while the GPS is powered up. (Probably a warming about that in the manual too...)
Pops the amplifier and now it's a de-tuned passive antenna instead of a tuned active device.
Lots of those high-gain low power draw amps have really touchy components that will die instantly if hit with static electricity too, with a bunch of components protecting the fragile transistor(s). Any minor misdesign there or in the power supply side, pop!
Pops the amplifier and now it's a de-tuned passive antenna instead of a tuned active device.
Lots of those high-gain low power draw amps have really touchy components that will die instantly if hit with static electricity too, with a bunch of components protecting the fragile transistor(s). Any minor misdesign there or in the power supply side, pop!
gismo
Touchdown! Greaser!
Nope, without gain (i.e. with a "popped" amp) the antenna cannot oscillate or radiate interfering RF. A passive network with rectification (which could be the case if an internal amp was off or damaged) tied to an antenna can radiat harmonics of ambient RF energy supplied by some other source such as a transmitting comm radio but that kind of interference wouldn't be continuous and wouldn't go away when you removed or cycled power to the radio/antenna.
AFaIK the problem antennas were simply poorly designed such that a sufficient amount of the amplifier's output was coupled back to the input/antenna. The amp itself has a fairly narrow bandwidth (to minimize noise) so when it breaks into oscillation the frequency will be very close to the GPS carrier.
denverpilot
Tied Down
Makes sense. I couldn't watch the video here at OSH but I thought you were having weak receive from the other descriptions. Not interference. Will have to watch when back home.