On 4 Sep 2003, Lars Petterson wrote:

In article ,
Fred wrote:
...
I had an IC-28A 2 meter rig do that. It was the squelch control itself
that had gone bad. And it is a real bugger to change due to the place it
is mounted.

Thanks for the info Fred!

Is that the TK-10420 IC? A 16 pin chip. The IC-448 uses one of those,
a narrow band FM IF chip, that also includes a squelch function. I
have gotten a circuit diagram and have found some odd voltages around
the IC, but I am still not sure if it is the IC, or any other component,
capacitor etc., that has gone bad. Have to do some more testing,
reflow some solder etc...

73 de Lars, sm6rpz

NO, the squelch control that goes bad is the actual mechanical pot, a
little bitty one with, thankfully a small wire harness attached that
solders into the front board. That is in the front of the rig, once you
take the face plate off you will see it. The wiper inside goes open and
that causes the squelch to not work any more. That is what happened on
this end any way. That by the way is only the second problem that I have
had with that rig. The other problem was the audio chip went bad and it
was easy to replace.

Fred KE8TQ



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