[RFI] RFI from 2005 Accord V6

dgsvetan at rockwellcollins.com dgsvetan at rockwellcollins.com
Thu Aug 9 12:26:45 EDT 2007


Although I have no experience with your make/model, I did have problems 
many years ago in a van when bonding leads that I had installed on the 
exhaust pipe deteriorated over a period of about two years and broke off. 
That resulted in a significant increase in ignition noise.  Your car is 
around 2 to 3 years old, so it occurs to me that maybe something that was 
properly bonded (or shielded) when the car was new no longer has a good 
bond to chassis or a shield.  Also, some component(s) may have failed or 
changed value - good luck on that.

A suggestion for locating the noise maker:  construct a sniffer loop out 
of a turn or two of insulated wire and a coax connector.  Connect that 
sniffer to your IC-706 (tuned to whichever band produces the loudest 
noise) and move the probe (with care!) around the engine compartment to 
see if you can find where the highest noise levels are located.  Don't 
forget to sniff around the exhaust pipe, as well.  (Since most exhaust 
pipes are solidly attached to the engine but are "floated" on hangers to 
isolate mechanical noise, they make excellent end-fed antennas for 
ignition harmonics.)  You may need a helper if you can not set the radio 
outside of the car while sniffing.  While you are at it, disconnect all 
antenna leads completely from the 706.  Does the noise go away completely? 
 If not, you may be getting conducted noise on the 13.6 VDC power lead 
into the radio.

Please infom us of what you find.

73, Dale

ab0yw <ab0yw2006 at gmail.com> 
Sent by: rfi-bounces at contesting.com
08/08/2007 10:31 PM

rfi at contesting.com

[RFI] RFI from 2005 Accord V6

I have a 2005 Accord V6.  As of recently, I'm getting broad noise across
HF.  In the past there was virtually no noticeable noise when the car was
running.  Now I hear around S6-S7 (ICOM 706) at any RPM.

   - There is no noise when the engine is off or when the ignition key is
   in the on position (engine not running).
   - The noise ramps up as RPM goes up.
   - I had Honda check the engine for misfires or other anomalies and it
   got a perfect check up.
   - The engine has coils/caps on top of the valve covers.  I've
   unplugged each cap while listening to the radio and been unable to 
   any change in the buzz.
   - I've wiggled all wires going to ignition components and the
   injectors without any noticeable difference.
   - I've clamped a wire to the negative battery terminal and touched
   other ground points to see if I could hear any difference to no avail.

Has anyone experienced something like this?  Could it be the injectors?
Appreciate any tips.


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