On Wed, 02 Jun 2010 06:41:16 -0800, dave wrote:
Kevin W0KLH wrote:
I just reinstalled my Icom back into my vehicle after it being out for
several months, I was listening to 20 meters yesterday and tried to
get into a few of the pileups that were going on. A second or two in
keying up to ID my call, the radio shuts off. I also have developed
what sounds like a ground hum on VHF.

For an antenna I am using a Yaesu ATAS-100 with a AM-COM controller.
When tuning the antenna in, I get to very low SWR's on the meter, so I
don't think that it is a high SWR that is causing it. I have checked
all connections and they are tight, so any thing further I can check?

Kevin w0klh

High current DC connections can get oxide inside without loosening.
Disassemble, clean with gentle abrasives and alcohol, reassemble, coat
with petroleum jelly. You are connected directly to the battery, right?

Good points. I've found the IC-706 to be bloody all sensitive to
voltages under about 12.59999999V.

A friend of mine found the original "butt contact" fuse holder was the
culprit. He accidently discovered the cause during one frustrating
session when repositioning the power cable by clasping the fuse holder
bodies (there are 2 of'em, IIRC). They were quite warm to the touch.

My installation involves direct, 10 ga. wires to the battery posts and I
am using automotive, blade-style, in-line fuses. Even then, I sometimes
need to remove the fuses, clean the blades, re-apply silicone grease
around the body and reinsert them to get the problem to go away.

Even given all that, I cannot park and operate SSB for more than approx.
20 minutes before the other OP eventually reports terrible distortion on
my transmission. I never operate FM -- I can imagine what problems that
mode can inflict on this problem.

A pox on their house for rolling out a rig that works so poorly under
such minor under voltages. It would not be my choice for a rig to rely
upon in an emergency.

73
Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
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