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Internal GPS

Posted: Tue Mar 19, 2013 9:41 pm
by Capflyer
I have the GRT internal GPS in my Sport SX. It used to bring up my position almost instantly then about 6 months ago it started slowing down. If I let the plane sit for more than a day it now takes a few minutes for the GPS to acquire the satellites. I spoke to Carlos about it a few months back and he sent me a new GPS antenna but that did not cure the problem. Is there an internal battery in either the Sport or GPS that perhaps needs changing or what else could it be?

Re: Internal GPS

Posted: Wed Mar 27, 2013 1:42 pm
by katieb
There's no internal battery in the Sport or GPS. There is an option to wire the GPS memory ("clock power") directly to the aircraft's battery, but this will slowly drain the aircraft battery down over time, especially if you don't fly very often. Loss of clock power would cause the GPS to lose time and position, which would require extra time on boot-up to locate the satellites.

We never used to connect "clock power" in our Sport-equipped airplanes because we didn't want the battery to drain down. So, each time we started up the airplane, it took a minute or two for the GPS to find its location.

Some GPS modules may have a capacitor to keep a small amount of power to the GPS clock/position memory. I'd have to check with the engineers on this. If that's the case, your capacitor may be going bad. It won't hurt anything, but it would take a few minutes for the GPS to locate the satellites.

Re: Internal GPS

Posted: Thu Mar 28, 2013 11:25 am
by Capflyer
Thanks Katie. Since it used to bring up the position very quickly (within a minute) and now taking up to 5 minutes it sounds like something is going bad inside. I typically fly every weekend and sometimes a day or two in between so the plane is rarely sitting more than a week without being flown. If as you indicated a capacitor inside is going bad then could that cause or be a symptom of a gremlin just starting his rampage?