Hangar Flying => Hangar Flying => Topic started by: TIM BAILEY on January 09, 2005, 08:52:28 AM
Title: RADIO INTERFERENCE
Post by: TIM BAILEY on January 09, 2005, 08:52:28 AM
I am getting radio interference from the right magneto...any ideas? :?:
Title: RADIO INTERFERENCE
Post by: Anonymous on January 09, 2005, 09:10:01 AM
Throw it in the garbage and buy and electronic ignition!! :D
Tom
Title: RADIO INTERFERENCE
Post by: Waiter on January 09, 2005, 09:53:09 AM
There are two different ways interference can come in, and this applies to electronic ignition or magnetos.
1) Radiation - In this case its actually coming in via the receiver RF path. This is most likely caused by a bad spark plug, wire, or distributor cap. ALSO - Install a "P" lead filter if you havent already.
2) Power Supply - The noise pulses are getting into the radio via the power source. Actually, I find that intercoms are more suseptable to this than radios. However, the same fixes apply. Check for bad plugs, wires and distributor caps. ALsao make sure the "P" lead filter is installed. If these are OK, then install a DC Line choke in the power line that supplies the radio and intercom.
Radio Shack used to sell these, However, I think this item is the same http://www.tessco.com/products/displaySkus.do?groupId=619&subgroupId=65
Its a Speco Technologies HLF10
Good Luck
Waiter
Title: RADIO INTERFERENCE
Post by: mapratherid on January 10, 2005, 04:25:46 PM
Did the noise from that mag start recently, or has it always been there?
Waiter's list of debug items is correct, with a couple of addtions... You could have a bad condensor inside the mag.
You can check to see if it is P-lead noise by completely disconnecting the P-lead from the magneto and running the engine. BE VERY CAREFUL doing this however, because AS SOON as you disconnect the P-lead, you have a HOT MAG situation. That means that the engine can't be turned off using the panel mounted switch - you'll have to turn it off via fuel supply - either mixture cutoff or fuel valve. It also means that being around the propellor is especially dangerous. Don't let anyone near the propellor while the P-lead is disconnected!! The engine could possibly spontaneously start; is likely to start if you bump the prop. Even with all of the warnings, it is still useful to eliminate a fault in the P-lead wiring by running the engine with it disconnected.