Sawzall with the 706 and Ford 500

[KB2OWB]

I just put the HF antenna on my Ford 500.  It's an Outbacker stealth plugged into the portable Icom 706.  I've worked VHF mobile with this setup (with an appropriate VHF diamond antenna) and never experienced the Sawzall sound on VHF.  HF has proven to be a debacle (hopefully for the moment).

I tune into 20 or 17 meters and get the nastiest, loudest tablesaw, buzz saw, sawzall, rip saw-type sound coming from the receeiver when the engine is fired up.  It gets louder and more pronounced when I accelerate.  It's obviously RF from the engine.  This has to be a common problem with a common solution that I need to learn.

The power cable is run through the floor, under the chassis and cabled directly to the battery.  Nothing but wire between the transeiver and the battery.  I suspect this is too simple to be true.

What's the solution?  I can't take the noise and want passengers to enjoy qso's and the art and excitement of hf while mobile.  What's the answer to this question which must be common?

[K0BG]

Go to my web site, and look under Noise ID. At least that will tell you what you're dealing with. There are other articles telling you how to reduce it to an acceptable level.

I suspect it is ignition RFI. If it is, the first place to start is plug and plug wires. If yours has COP units, you might still want to change the plugs, and install 1181 copper tape on the COP units.

Alan, KØBG
www.k0bg.com

[XY3LON4]

A capacitor installed on the alternator will probably do the trick. Need to make a sniffer to find out where it's coming from.