Perhaps its just that now the GPS is onboard, its closer to the other electronics on my jDrones hexa - but I'm suffering with an inability to get a 3D fix on the GPS.
My previous setup had the radio RX (JR RG831B DMSS receiver) and its telemetry unit (RA01T) on the lower carrier plate, the APM1 on the top plate, and the GPS receiver on the top of the dome on a standard jDrones hexacopter. This worked fine, GPS always got lock and seemed pretty stable.
Moving to the APM2, I've still got the radio RX on the lower plate, and now the APM2 above it. However, if the RX is powered, then the GPS won't lock - it occasionally acquires 1 or 2 satellites but never makes it further.
I've tried to isolate it somewhat - powered the 2 devices separately (APM2 from USB, RX from a lipo+BEC) and removed all the interlinks - still see the same problem. I've covered the top plate with foil, then place the APM2 onto foam on the foil - and it was better until I hooked up the PWM connections. I've removed the RA01T telemetry TX and that makes no difference.
If I place the APM2 alongside the RX, its fine. ie. if I remove the top plate and place it alongside the bottom plate on my work bench - then indoors I see 5 or 6 satellites and get a 3D fix.
Is this just a 'noisy' DMSS receiver? Is anyone else seeing this? Is there a recommended layout of the electronics that I've missed?