[Mobile-Portable] Noise in a Highlander

Thu, 5 Sep 2002 21:38:28 -0700 (PDT)

High Dick,
RF noise is always the most evident on AM but it
certainly will affect the other modes to some extent.
I don't have a solution to your problem, but it is
suspicious that your noise sniffing indicated that it
was coming from under the drivers seat.  I don't know
about the Toyota Highlander, but many vehicles have
their main computer control located under the drivers
seat.  A friend of mine had this problem and he ended
up having some success by shielding the computer under
the drivers seat.  This may or may not be the
situation you have.  Good luck.
Robert  N6OI

--- Dick <[email protected]> wrote:
> I have an interesting delima in my mobile HF
> installation.
> Vehicle:    2002 Toyota Highlander
> Radio:    Icom 706 MKIIg
> Ant:    High Sierra screwdriver.
> 
> I'm experiencing a noise that is very evident in AM
> on 10 - 20 meters
> (almost S9) but even though I can't hear it, suspect
> it's causing some
> desensing on SSB or CW as well.  The noise is
> present only when the
> engine is running, is constant in frequency, and
> sounds almost like two,
> one about 600 Hz and the other an octave lower. 
> It's not the fuel pump,
> (ignition on it's quiet until the engine is
> running... a fuel pump, in
> my experience would run for a short period when the
> ignition is first
> turned on and if that were the case, I'd hear the
> noise then, but I
> don't) or any fans, (as near as I can tell, they are
> all turned off) and
> I'm certain it's not the alternator because it
> doesn't change
> frequency.  I used a piece of coax with a loop on
> the end to try to
> sniff out the noise and... are you ready for this...
> it appears to be
> originating from under the drivers seat.  I put
> several snap-on ferrite
> cores (similar to what is on a computer power cord)
> on the coax as it
> leaves the antenna and that reduced the noise
> somewhat so I'm suspecting
> it's coming in on the shield as well a being picked
> up by the antenna.
> I haven't looked at the noise with an o'scope nor
> have I connected the
> control head directly to the radio, sans cable, but
> that's my next step.
> 
> Is anyone running HF in a Highlander and or
> experienced something
> similar to what I'm hearing?
> 
> BTW... I was having RF shut-down as experienced by
> Scott, KA9FOX and
> solved that with a good ground at the radio and a
> ferrite core on the
> separation cable for the control head.
> 
> Tnx es 73
> Dick
> --
> Dick Bodine, N0IM
> Duluth Minnesota
> mailto:[email protected]
> 
> 
> 
> _______________________________________________
> Mobile-Portable mailing list
> [email protected]
>
http://mailman.qth.net/mailman/listinfo/mobile-portable

__________________________________________________
Do You Yahoo!?
Yahoo! Finance - Get real-time stock quotes
http://finance.yahoo.com