IC-736 Squelch Won't Open

Discussion in 'Radio Circuits, Repair & Performance' started by K0MSM, Jun 15, 2020.

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  1. K0MSM

    K0MSM Ham Member QRZ Page

    Greetings all -

    My dad (W3RMM) became a SK back on March 5 of this year. I took his IC-736 under my wing to use it and hopefully get back on HF again. (Sold his FT-897.) This weekend, I finally got around to getting the 736 hooked up and in service, and it appears that the squelch circuit is not functioning correctly. It simply will not open, except very intermittently for a second or two, and then only when the control is turned all the way CW, then all the way CCW. After about a second or two of opening intermittently, it will close again. This happens regardless of whether or not a strong signal is present, and whether or not the preamp is turned on.

    I checked on the Icom site, and I see that this radio is no longer supported for repair. Has anyone else out there run into this problem on the 736? Or any suggestions on a company that might be able to help diagnose and repair the problem, if it can even be repaired at all?

    I'd love to use this rig in my dad's memory. We both got our licenses in 1978, and it would mean a lot to be able to use it to get back on HF again.

    Thank you!

  2. N8VIL

    N8VIL Ham Member QRZ Page

    I would try cleaning the pot first with a quality contact cleaner made for pots. I use the brand DeOxit. I had to clean mine about 10 years ago for the same problem. You will have to loosen the front panel to gain access to it. If I remember correctly, I had to remove the front panel bezel also. I think it gets intermittent from lack of use. I make it a habit of operating seldom used controls once in awhile to "wipe" the contacts. Switches and pots. I have repaired a few of this model Icom for various problems and I am very familiar with it. Another common problem with this model is the electrolytic capacitors in the power supply. I would look at those while you are in there. Every one I worked on needed attention in that area.
    Last edited: Jun 15, 2020

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