On Tuesday, January 21, 2014 8:09:23 AM UTC-8, Henry Retting wrote:
OK all you radio gurus.....voice your opinions

maybe I should install a fire extinguishing system.....seriously now..

anybody see any issues of electronic interference between units. The Transponder will be used mainly at home with all the business jets around.

Thanks for you help.

H

Power it all up and if the smoke and burnt wiring smell isn't overwhelming, proceed checking to see if you have any radio interference.

Turn off all avionics except radio. Tune radio to a low frequency, 118 or so, adjust squelch so it just squelches background noise. Turn on all the video games and doo-dads. If squelch is still quiet, good. If not adjust squelch up a bit to quiet it. Then start tuning the radio up the band to higher frequencies. It's possible that you may have a narrow frequency band of strong RFI at a specific frequency (e.g. 122.7). If you do encounter a frequency specific band of noise, stay tuned to it and turn off avionics one at a time to determine which device is guilty.

Sometimes installing ferrites on the offending equipment wiring, as close to the device as practicable, will reduce the RFI if it is being radiated by the wiring or being inductively coupled etc. A handheld radio can be useful to determine if the RFI is exiting the box via wiring or somehow being transmitted (radiated) from within the box.

Ferrites are available from Digi-Ket or Allied. The clamp on type are easy to apply. If you have enough wire slack to make a loop or two through the ferrite, that will improve effectiveness, so get ferrites with a large enough hole.

Next see it your are getting a reasonable constellation of sats on your GPS devices. If one or more isn't getting sat lock or is marginal. Turn everything else off, one by one and see if that points out the culprit. If reception improves when turning off another GPS, turn that GPS back on and try relocating its antenna.

Shorten all that extra transponder wiring :c)

Install a MKIV "high tech" yaw string and Quiet Vent.

bumper