[Icom] IC-2100H not muting properly

Thu, 5 Dec 2002 07:37:06 -0600

Fern,

  The noise that you are hearing during transmit (crackling/static from
speaker that is typically worse at higher power levels) is due to grounding
problems inside the radio. I had a similar problem and here's how I
addressed it...

  I opened the radio-up to check the screws that were holding-down the
radio's PC board. I found the screws on the board to be fairly snug.
Regardless, I placed star washers under some of the screws and tightened
them all down (simply retightening the screws may be adequate).

  I also noticed that one of the two solder bridges that connect the ground
side of the SO-239 to the board looked like it was cracked. I reflowed the
solder on both of these solder bridges (the SO-239's center conductor
connection looked fine) and closed-up the rig.

  The crackle/static problem I had on transmit is now completely gone (even
on high power). If you have this problem and are thinking of doing trying
this fix, I would make the following suggestions: Use star washers that are
small enough that they will not short any nearby traces to ground (some of
the PC board mounting screws have small traces nearby). The gaps between the
SO-239's ground "pins" and the PC board look like they might be as large as
an eighth of an inch or so. This is a pretty big gap to be bridged by
solder!
In retrospect, I probably should have run a small piece of stranded wire
across the gap to make the bridge more robust -- I'm sure these solder
bridges are seeing some stress due to thermal expansion/contraction.

  73, Michael N9BDF

--__--__--

Message: 10
From: "Fern Rivard" <[email protected]>
To: <[email protected]>
Date: Wed, 4 Dec 2002 21:50:02 -0800
Subject: [Icom] IC-2100H not muting properly
Reply-To: [email protected]

Has anyone noticed if their IC-2100H lets out some squelch noise at times
when in transmit mode?  73's from Fern