Electrical Soup

[Cee Vee Ess]

Can someone please help and advise. When I transmit while flying my trike. The altitude/QNH and EGT go wonky on me and give me very high readings? I also have problems with my headset when carrying a PAX. When the pax headset is plugged in, my comms fall to a barely audible quality, so I just unplug the pax mike jack and he can hear me fine, but he cannot talk back offcourse. I have 3 buzzcom headsets (one brand new) and does not matter which one I put where it always does the same!!

[Wargames]

There might be a short somewhere. First check/rewire the basic wires. If that doesn't work, you need to send your intercom for repairs.

[Biggles]

I was with CVE in the hangar and donated an extra isolated power supply unit I had. If he hooks the radio and intercom up through that will it sort out the sort issue?

[Jimbo]

Ok, I know (less than) zilch about aeroplanes, so before I comment I need to ask.... do the electrical systems work like those in cars, where one half of the pathway is through the frame or other common return?- the so-called earth?

Becasue if so, that may well be the problem here. A bad earth in a car (as opposed to a short... an open or not well made circuit, the opposite of a short (a long ) causes all sorts of funny symptoms. When one component is activated and there's a bad circuit, electricity gets a bit like water and finds its own way round, sometimes routing through other parts with strange results.

So yes, the suggestion to check the wiring is a good one... don't just look for short circuits (eg frayed wiring accidentally connecting to other parts, wires accidentally clamped where the insulationg might possibly be broken (but usually not all that apparent); look for open or poorly made circuits too (eg loose connections, or wiring tabs screwed to components where there might be paint preventing a good connection). In any case, a poor connection that might be arcing can cause all sorts of radio interference I think.

HTH?

Jim

[Cee Vee Ess]

Yip thanks to Biggles half my trouble might be sorted out. And I have decided to have a go at all the wiring and perhaps redo some of it.