SV-GPS-250 not giving position source

Ernestn

New Member
Joined
Jul 14, 2020
Messages
6
Back in July 2020 my SV-GPS-250 started working intermittently. Since then it has stopped working all the time and gives me a "No GPS Position Source" error. I have it set up in serial port 5 as POS 1 and as a SV-GPS-250. I turned the Skyview unit on and measured the following voltages in the wires going to the GPS:
between black (pin 24) and orange (pin 29) 8.09 volts;
between Gray with violet (pin 11) and Black (Pin 24) 6.47 volts;
between Gray with orange (pin 12) and Black (pin 24) -5.68 volts;
between Pin 11 and 12 12.15 volts.

On serial port 2 I have a Trigg TN72 gps input as POS2. If I power it up the Skyview GPS error goes away and it operates fine using the Trigg GPS source.

Based on the above data can anyone tell me whether it is the SV-GPS-250 unit that is faulty or could it be the D700 Skyview that is faulty? Is there anything else I should check?
 

kellym

I love flying!
Joined
Sep 29, 2013
Messages
273
Back in July 2020 my SV-GPS-250 started working intermittently. Since then it has stopped working all the time and gives me a "No GPS Position Source" error. I have it set up in serial port 5 as POS 1 and as a SV-GPS-250. I turned the Skyview unit on and measured the following voltages in the wires going to the GPS:
between black (pin 24) and orange (pin 29) 8.09 volts;
between Gray with violet (pin 11) and Black (Pin 24) 6.47 volts;
between Gray with orange (pin 12) and Black (pin 24) -5.68 volts;
between Pin 11 and 12 12.15 volts.

On serial port 2 I have a Trigg TN72 gps input as POS2. If I power it up the Skyview GPS error goes away and it operates fine using the Trigg GPS source.

Based on the above data can anyone tell me whether it is the SV-GPS-250 unit that is faulty or could it be the D700 Skyview that is faulty? Is there anything else I should check?
 

kellym

I love flying!
Joined
Sep 29, 2013
Messages
273
I had my 2012 vintage GPS-250 fail in the same way over the past 7-8 months. The good thing is that there are enough builders on my airport who had to upgrade to GPS2020 for ADSB, and still had the GPS-250 they replaced on hand. Made a deal for one, and all is good again. I was told they rarely failed and spent a lot of time verifying and improving connections, which did not help at all.
 

Ernestn

New Member
Joined
Jul 14, 2020
Messages
6
Thanks Kelly - I too checked all the connections - doesn't seem to be that. I should probably try to pick up a used one too.
 

jakej

Well-Known Member
Joined
Oct 10, 2007
Messages
2,167
Location
Adelaide, Australia
I have know the connection at the base of the 250, & presume the same would happen with the 2020, to become intermittent or fail without an obvious break due to too much 'handling' - there is no need to do that, just put it away until it's ready to use ;)
 
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