[Icom] Mobile Noise - Good News and Bad News

[Davies, Doug A FOR:EX]

Did some things last night and I've got some good news and some bad news.
First the bad news.

I planned to try shielding the computer with aluminum foil to see if I could
get any reduction in the noise.  Took out the glove compartment to get at
the computer and discovered that it is housed in a very sturdy metal box
already.  Not much chance of noise getting out of there.  I ran an
additional ground strap from the box to the firewall just to be sure but it
made no difference at all in the noise.  So much for that.

Now the good news.  On the way home from work, I took another chance and
stopped in at my Toyota dealer and asked again if they would PLEASE help me
find the source of this noise.  Well, their senior mechanic must have had
pity on me.  Even though he was just getting off work, he went to his tool
box and pulled out some sort of analyzer.  He plugged this into a port under
the dash and said he could perform all sorts of diagnostics right from the
analyzer.  First, without the engine running, he turned on the fuel pump.  I
had the 706 on and could hear a very faint increase in background noise but
nothing that would be a "show stopper".  He then turned on other stuff while
I listened on the radio.  Nothing he did made the now famous noise.  He then
disconnected the analyzer, I started the truck and VOILA, the noise was
there...solid S-7.  The mechanic had no explanation of what could be causing
it.  So, I guess it wasn't all good news after all.  However, I have revised
my opinion of the Toyota service department so I guess that's the good part.

Doug  VA7DD