Wiring the capacitor into the system

Re: Wiring the capacitor into the system

by bill martin » 13 years ago

bill martin

10 757 0

Wayne,

the capacitor is wired from R, B+, and C of the regulator straight to ground. You can download the 912 installation manual for the wiring diagram. If you have an electric fuel pump, its capacitor is wired straight across the hot and ground pump connections.

The capacitors are probably not where your radio noise is coming from though. usually its from ignition or strobes. There is not a clear cut method of eliminating RF noise. All installations are different. There are some basic things you can do however.

Ground EVERYTHING well. Radios, strobes, nav equipment, coax shielding, etc. Especially the engine block.

Try to locate the antenna so that it cannot "see" the ignition system. Anything you can keep between the antenna and the ignition or strobe power supply such as your body, the airframe, the radiator, will help.

Keeping the sidetone turned down low in the radio sometimes helps.

Installing RF chokes on power wiring sometimes helps. Especially the power supply to the radio. You can get the snap-on type at Radio Shack for less than a dollar each.

Every planes' RF noises are different and it will just take a lot of trial and error to find what works for you. Sometimes a single fix will do it and sometimes (usually) its a lot of little fixes that work.

Bill.

Re: Wiring the capacitor into the system

by bill martin » 13 years ago

bill martin

10 757 0

Wayne,

I forgot to add one item. Be sure that the mag switch wires from the cockpit switches to the modules are shielded and the shielding is grounded on both ends. Also ground the switch cases.

Bill.

Re: Wiring the capacitor into the system

by wayne taylor » 13 years ago

wayne taylor

1 1 0

Thank you Bill. I willl start working on the grounds and shielding tomorrow. I do nor have the mag wires shielded inside of the cabin. I also do not have the tach wire shielded. Hope it works.

Wayne

Re: Wiring the capacitor into the system

by John Car » 4 years ago

John Car

3 6 9

B+ to ground through the cap???  Does not seem right??