My interesting GPS issue Monday

OneTwoSierra · #1 01-30-2007, 03:26 PM

Monday I was flying back home to the DFW area from central Arkansas and as I was just past Lancaster(LNC) there were a couple Chinooks crossing in front and a few hundred feet below my position. I crossed behind them about 1 mile away and my GPS lost it signal. A couple miles later, it reaquired the satellites.

Cooincidence?

The GPS has never lost the signal before.

RV7Guy · #2 01-30-2007, 04:34 PM

I had the same issue when flying in the NW Texas area last summer. Later research showed a Notam that wasn't real obvious. The Notam said that areas within xxx miles of White Sands NM could experience intermittent GPS signal.

Dan's Weathermeister is the only place I have seen some of these more obscure Notams.

johnp · #3 01-31-2007, 08:48 AM

Quote:

Monday I was flying back home to the DFW area from central Arkansas and as I was just past Lancaster(LNC) there were a couple Chinooks crossing in front and a few hundred feet below my position. I crossed behind them about 1 mile away and my GPS lost it signal. A couple miles later, it reaquired the satellites.

Cooincidence?

The GPS has never lost the signal before.

sounds to me like you were very close to the cedar hills antenna farm -- it would seem to me that that would more likely be the cause of the inteferrence. i never lost gps there -- heck, i moved away from the dfw area before i had a plane with gps in it, but the rf from cedar hills used to break the squelch on my narco mk-12d's.

just a thought.

john

Ironflight · #4 01-31-2007, 09:27 AM

Quote:

Originally Posted by johnp

sounds to me like you were very close to the cedar hills antenna farm -- .

john

We have a similar antenna farm down here in Houston in Missouri City (on the southwest side). Departing westbound under the Class B, you get squeezed between them and Houston Southwest's traffic pattern, so you get pretty close. I have never had a problem with my main GPS's in this area, but my 396 with the "little" external antenna loses lock every single time I pass by them, without exception. Makes me think that I'm glad I'm not planning on having any children...

Paul