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Re: [VHFcontesting] Parts for TR-751a Vol Pot On/Off

To: vhfcontesting@contesting.com
Subject: Re: [VHFcontesting] Parts for TR-751a Vol Pot On/Off
From: jcplatt1@mmm.com
Date: Wed, 13 Feb 2008 11:55:27 -0600
List-post: <vhfcontesting@contesting.com">mailto:vhfcontesting@contesting.com>
Hi Bruce, thanks for the good info.  Yup, I had a few fellows send me a
reference to the old "Kenwood East" website and noted that the pots are now
discontinued and out of stock.   Darn.

I have one TR-751 that has a broken RF/SQL pot.    Opening up the unit and
ohming out the pot showed that it had failed electrically open end-to-end.
This failure mode results in reduced sensitivity and high squelch, so it
needed to be fixed.   Since I use this rig as an IF rig for the uW, since I
seldom use the control, I decided to simply cut the wires and replace it
with a fixed resistor of the same value.   That got the radio operational
again, albeit with no RF gain & squelch control.

My second TR-751 has a scratchy volume pot, and I am concerned that it may
be failing.  Let me know if you are ever able to get your "scratchy pot:"
fixed as I would be interested in what you did.   If it does fail on me
sometime, my thoughts would be to replace the volume function with a (near)
equivalent pot and to add a separate on/off switch .... not too big of a

Both radios are used for uW duty where they are excellent.   I did defeat
the HI/LO power switch so that its always in LO power mode by cutting the
control wire that runs to the HI/LO button on the front panel.   When this
line floats, the radio is in LO power, grounding the line via the HI/LO
switch cause it to go into high power mode.   This helps to assure that I
don't accidentally go into HI power mode.

73, Jon
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