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Old September 15th 06, 06:35 AM posted to rec.radio.amateur.equipment
Pete KE9OA Pete KE9OA is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 271
Default Icom Tuning?...Help Please

It's funny that when Clayton turns the encoder quickly there is a frequency
change. I repaired a Kenwood R5000 a few months back that had the same
problem. The cheap plastic disc inside of the encoder was slipping from the
tuning shaft. I was able to super-glue the assembly back together and get it
working again. If it was my own receiver, I would have probably replaced the
encoder with either a Grayhill or Bourns optical encoder.

Pete

"Bob Miller" wrote in message
...
On 12 Sep 2006 22:46:06 -0700, "Clayton" wrote:

Hi,
I have an Icom IC-290A that I am working on...The problem being that
when I turn the tuning knob it doesn't change frequencies,it acts as if
the knob is slipping.


I had the same problem with an Icom 735. The tuning knob turns an
encoder, which had stopped working. Icom no longer sold the encoder. I
found a repairman who figured out which diodes were burned out, and he
replaced them and got the encoder working again. You might look for a
good repair guy.

Bob
k5qwg


After determining that it wasn't the knob slipping I proceeded to
disassemble the front to get at the tuning potentiometer.
If your familiar with this unit you know that the potentiometer is
continuous and has teeth that catch when you turn the knob to make
tuning easier.
Now when I hook up my ohm meter to the wiper and to either end of the
potentiometer all I get is an OL reading and when I turn the shaft the
reading jumps around wildly. If I connect the meter to the wiper and to
the case of the(I am assuming this is correct?) potentiometer I should
get a reading of Zero ohms but again the only reading I get is OL.

Am I safe in saying that the potentiometer is bad?

If so how do I go about figuring out what type of potentiometer I need
to replace the bad one?
The schematic doesn't tell me what value it is and there isn't a parts
list or part number either.

I hope I have made myself clear enough to be understood,if not please
let me know so I can try and make things clearer.

Any help on this would be greatly appreciated.
Thank you