FT2900R excessive deviation problem please help

Discussion in 'Radio Circuits, Repair & Performance' started by KJ6SQH, Oct 27, 2019.

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  1. KJ6SQH

    KJ6SQH Ham Member QRZ Page

    I have a 6 year old, barely used FT2900R Yaesu rig. It sat on a shelf for about 4 years, unused. I recently connected it to power again, and now the transmit audio cuts out terribly. It was checked by another station with a deviation meter, and I was informed it does have excessive deviation. I tried switching to narrow deviation and the problem was still present. Another symptom that showed up at the same time, is when I turn on the 13.8v power supply, with the 2900 off, the 2900 display flickers momentarily when the power supply is initially turned on. The 2900 performs normally in every other aspect. My first check was to see if the power supply is spiking when turned on, but nope. A perfectly stable 13.8 vdc at all times. The supply being used powers my Ftm400xdr beautifully, and no display flicker on the 400 at power up. A new replacement (ft2980) can be had for less than $150 on sale, but to toss aside this 2900 would seem a waste of an otherwise great radio. Any help would be appreciated.
     
    Last edited: Oct 27, 2019
  2. KJ6SQH

    KJ6SQH Ham Member QRZ Page

    I need to add the excess deviation seems to have no effect on simplex communications, only when transmitting into repeaters.
     
  3. KA9JLM

    KA9JLM Ham Member QRZ Page

    That don't really sound right. Deviation should be the same, Maybe the repeater you are using is more critical. Maybe the repeater PL tone affects the repeater input.

    Have you cleaned the Mic connector ? They are bad about loosing connection.

    Good Luck.
     
  4. K6BSU

    K6BSU Ham Member QRZ Page

    "Deviation" applies to FM operation. Do you transmit FM to your repeater? Perhaps you refer to some sort of waveform "clipping" on peaks, which is caused by over-driving the transmit audio. Have you tried reducing microphone gain, or turning the compression to OFF?
     
  5. AG6QR

    AG6QR Premium Subscriber QRZ Page

  6. KJ6SQH

    KJ6SQH Ham Member QRZ Page

    Thank you for the replies. I tried all the above, deoxit on the mic connection, played with the mic gain, etc. still no joy. Additional testing confirms deviation is far too wide, so I’m dropping the unit off at Yaesu’s repair facility which turns out is a few miles from me. Thanks again for your assistance.
     

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