GPS failures

[lucaberta]

Originally Posted by s_tones

Not sure what the deal is. I've got the antenna on the glare shield.
It's about 2 feet from my PCAS device. Maybe an issue?

PCAS is a purely passive system, as far as I know, but since a receiver inherently has a small transmitter on board (its local oscillator), it could very well be that some spurious signal interferes with the 296.

Have you tried to turn off the PCAS and see if the 296 still loses lock? That is a good indication on whether there is an interaction between the two systems.

I'm gonna try a higher gain antenna or, if possible, hooking into my external GPS antenna (which currently serves my SL60 GPS).

be careful when doing this kind of stuff! GPS antennas are typically powered by the receiver thru a phantom power (normally 5V, but 3.3V is more and more common), and you can't simply split the signal without taking care of the DC coming from the other receiver.

I've bought for real cheap at Radio Shack a satellite TV splitter and a DC block connector, and it works fine. Actually it's a 4-to-1 unit, so I can hook up up to 4 GPS, and of course I need 3 DC blocks to filter the DC from the secondary GPS receivers. Unfortunately the unit has F connectors, so I had to also connect a few F-to-BNC connectors, but it was a simple task.

This is setup is not flying yet, I am planning on installing it on my Pipistrel Virus sometimes in the future, to share the Garmin antenna with a Bluetooth GPS that I will hide behind the panel, so I can use stuff like PocketFMS easily in my cockpit.

Ciao, Luca

[RVadmirer]

While bringing my plane home to Calif. from New York my new 396 lost signal three times and all 3 were crucial.
I kept the stick antenna handy the second day and used it when signal was lost. When I got home I told Garmin and they sent me a new antenna. Problem solved.

[airguy]

It's never happened to me in the air despite a few years of regular use - but my 196 loses it's mind in my pickup everytime I put my truck radio (factory 2006 Chevrolet) into AM mode. FM and XM - no problem, but AM wipes it out completely every time. Must be the IF oscillator in the radio. Even having the radio in AM mode and pushing the on/off button still keeps the GPS out of lock, though you aren't actually powering down the radio by doing that, just stopping the audio output. It does this with both the stick and remote antenna, and the effect disappears about 5-6 feet from the pickup.