[Mobile-Portable] First step to cure engine noise?

[email protected] [email protected]
Mon, 21 Apr 2003 09:10:40 -0700


BE CAREFUL OF DIESELS - now that most of them use electronic
fuel injection, most of them are noisy!!!  My '95 Ford F-350
powerstroke diesel kills HF and gives 6m some problems.  This
is due to the fact that the electronic fuel injectors are fired
by an Injector Drive Module (IDM) which grounds 110VDC each time
a cylinder is "injected"!

I understand that the 2003 model is MUCH, much quieter, and I
think it was 2001 that wasn't TOO bad, but the rest stink (at
least at HF)!  The noise is gone by 144MHz - it's not true impulse
noise like gas engine spark plug noise; the rise/fall times are
slow enough that it starts tailing off above 10m - as I said,
still there on 6m, but not nearly so bad as on HF!

Bottom line - if you are buying a diesel, don't make the same
mistake I did, and make sure it doesn't have electronic fuel
injection OR bring your IC-706/FT-100 (or equivalent) along to
the dealership, with some kind of mag mount vertical, start the
vehicle, and check all bands from 80M thru 70cm to see what you've
got before you buy!!!

Good luck!!  The OLD diesels, with mechanical timing and injector
pump are noise free, but the vehicles are aging....

GL & 73, Paul ND2X/5

>--- Original Message ---
>From: "David E. Shelton" <[email protected]>
>To: "'Scott Neader KA9FOX'" <[email protected]>, <[email protected]>
>Date: 4/21/03 9:18:24 AM
>
Simple, buy a diesel vehicle, but seriously eliminate any possible
floating
>ground situations, by interconnecting the chassis, exhaust system,
and
>sometimes a hitch type mount can play havoc on an antenna system.
>Electrically the antenna can see this as an intermittent connection
to
>ground, with moisture, vibration, and combination of these conditions
it
>will intermittently provide a ground loop, in effect another
receive antenna
>path for the noise to come into the rig. Just temporarily ground
from the
>feedpoint where the shield of the feedline goes to ground and
run a short
>strap bypassing the hitch mount if not already done. Just my
two cents
>worth. If you have already covered this angle sorry for the
bandwidth. 
>
>David E. Shelton, RN
>N4IN
>[email protected]
>[email protected]
>
>
>-----Original Message-----
>From: [email protected]
>[mailto:[email protected]] On Behalf Of
Scott Neader
>KA9FOX
>Sent: Monday, April 21, 2003 1:08 AM
>To: [email protected]
>Subject: [Mobile-Portable] First step to cure engine noise?
>
>Hi All!
>
>I have an IC-706 in a 1997 Chevy Tahoe, with a Hi-Q-Antennas
3/80 mounted 
>on the hitch-mount.
>
>Anyway, the problem is:  engine noise (engine whine)
>
>The Noise Blanker is pretty good in the 706, so I've avoided
trying to cure 
>the problem, but there are issues with the NB as you probably

>know.  Distorts when there are nearby loud signals, etc.
>
>What is the first, easiest step to try to reduce engine noise/whine,
that 
>you have found to be successful?  Any owners of 1997 Tahoe (or
Surburban or 
>Yukon) with tips to share?
>
>Please reply directly and I'll summarize back to the group if
there is 
>enough information to share.
>
>Thanks & 73!
>
>---------------------------------------------------------------
>Scott Neader KA9FOX   (608)788-1234 / FAX (608)787-0100
>Free Ham Radio Classified Ads:  http://swap.QTH.com
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>
>
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