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Icom IC-27A Volume Potentiometer

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by N1CZZ, Aug 24, 2014.

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  1. N1CZZ

    N1CZZ XML Subscriber QRZ Page

    I have an Icom IC-27A two meter mobile radio. I am going to be testing to see if the pot is bad, it has super low audio. To the best of my knowledge these pots can't be bought anymore. I haven't found a substitute mentioned on the web yet. I have an idea, I'm thinking of wiring in a resistor that will provide just enough audio to hear in a quiet environment and then use an external speaker that has amplification and volume control like computer speakers. I will need to get a mono to stereo plug. Does anyone know what the resistance range is of the existing pot and or have some suggestions as to what value to try first?
     
  2. K7MEM

    K7MEM Ham Member QRZ Page

    According to the schematic, the volume control is a 10K pot with a switch on the rear.

    However, you might want to check out http://www.qsl.net/wb4kdi/Icom/ic-27_Audio.html first. It seems that low audio is a feature of this transceiver. The author provides a little bit of insight into the issue.
     
  3. N1CZZ

    N1CZZ XML Subscriber QRZ Page

    Thank you Martin, the audio on mine is so low you wouldn't know it had anything unless you put your ear to the speaker, and it doesn't make a difference where you set the volume. These radios are also known after 20+ years for the volume and squelch pots to go bad. I took it apart yesterday but it is a little more work to get up the pot then I hoped, so I put in back together for now.
     
  4. WD5DON

    WD5DON Ham Member QRZ Page

    Steve, you might take a look on the Mouser website and see if the Bourns PTD901-2015K-A502 looks like your rig's pot. They may have used the same pot in both the '27 series and the '38 series. I replaced the one in my IC-38A with this one and it fit and works perfectly.

    The only other thing I had do was jumper the power leads, as the Bourns pot doesn't have a switch. I have read of other people putting a replacement pot somewhere else, but personally, I'd rather have a front panel volume control and have to hunt (or do without) a power switch than the other way around.

    73, Don
     
  5. N1CZZ

    N1CZZ XML Subscriber QRZ Page

    It says mine is a 10K, I found the one you mentioned and used that to find one that is a 10K instead of 5K. PTD901-2015K-A103 Will let you know if it fits.
     
  6. N1CZZ

    N1CZZ XML Subscriber QRZ Page

    Pot is on backorder and I'm not sure it would fit so today I went and found what I thought to be the two solder joints that are for the volume control, shorted them out, got full volume. Soldered two wires to it, then a 4.5K ohm resistor to the wires, still very loud so solder another one in series. Closed the radio back up, plugged in my mono male to stereo female adapter and an old set of computer speakers and viola, radio works good, I have audio and I can adjust it. It was hard getting to that pot. I'm happy, got this old gem of a radio for $15.00 at a hamfest and after a couple hours work it works as new. Will use this one in the house and my IC-228 in a vehicle.
     
  7. K8ERV

    K8ERV Ham Member QRZ Page

    Luvit when a plan comes together.

    TOM K8ERV Montrose Colo
     
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