2002 Hyundai Elantra RFI Noise

[N7KSM]

I have recently installed a IC706MKIIG in my 2002 Hyundai Elantra.  I have been able to use the UHF an VHF portion with little problem but whan I turn to the HF band I get about s7 of hash.  I know the interference is radiated and not coming througn my power hookups.  When I disconnect the antenna the noise stops.

I have already tried the normal ground procedure; hood, trunk, radio, antenna, muffler. There was little or no improvement.  I put together an rf sniffer and my worst fears became reality.  Most of the RFI is coming from the engine (probably the spark plugs).  A lesser amount from the fuse box and some more from (what I believe is) the computer control unit under the dash.

I already plan on using a few dozen snap ferrite beads on all cables coming from the computer control unit.  I am also thinking of building a sheet metal cover for the plastic fuse box and grounding it.  And plan on using copper braid to ground the outside of the spark plug leads

I was wondering if anyone else has an HF setup in their 2002 Hyundai Elantra? If so are they having the same problems as I am. Also, does anyone else have any suggestions?

Thank you,

Dale N7KSM

[AA4PB]

RF "hash" has two likely sources; the fuel pump or the computer. If you turn on the ignition (but not start the engine) the fuel pump in most vehicles will activate for a couple of seconds in order to pressurize the line and then stop. If you hear the hash for a short time and then it stops when turning on the ignition it is most likely the fuel pump.
 

[K0BG]

It isn't the vehicle you purchased, it "Welcome to HF Mobile". Are you sure it's hash? Bob Lewis, AA4PB, gave you the right answer if it is, although it could be the IAC (idle air controller). I suspect it's ignition noise. There is a lot you can do.

On my web site, http://www.k0bg.com, I have links to all of my articles I've written for eham.net about noise abatement in HF mobiles. I've expanded on some of them and they are posted on the site.

Incidentally, the Hyundai uses Mitsu and Denso electronics, and they're both some of the better designed automotive hardware out there.

Alan, KØBG