Garmin 155/165 Satellite Reception

[turbomax97]

On a certain aircraft that I know of.....

The GPS is very inconsistent on its loading. It will do the self test and then continue to the satellite reception screen - sometimes it will receive within 10 seconds, sometimes it takes 20 - 30 minutes(Read: after departure) for it to come up. It hasn't really affected anything as far as navigation goes, but it ends up being a nussance and wasting time on freq asking for a vector. Most of our flying is at night direct to whatever fixes/ airports we ask for.

We just updated the database card as well, so that's one possibility ruled out.:dunno:

 

[woodreau]

I don't know about the specifics of your particular GPS, does it have a backup battery to keep the memory going when the avionics unit/aircraft is powered down? That battery might be dead.

Normally there is an almanac loaded in a gps receiver which tells it where all the satellites are (ephemeris data) and from that it kind of know where to look for them. When it hasn't been turned on in a while or if its loses it's copy of the almanac for whatever reason, it has to download the almanac from the GPS satellites and it takes a while to do so.

 

[turbomax97]

I don't know about the specifics of your particular GPS, does it have a backup battery to keep the memory going when the avionics unit/aircraft is powered down? That battery might be dead.

Normally there is an almanac loaded in a gps receiver which tells it where all the satellites are (ephemeris data) and from that it kind of know where to look for them. When it hasn't been turned on in a while or if its loses it's copy of the almanac for whatever reason, it has to download the almanac from the GPS satellites and it takes a while to do so.

Hmm. It sounds like it's that battery. I'll bring that up - thanks!