Yaesu FT1000D Low power on SSB

Discussion in 'Radio Circuits, Repair & Performance' started by KD4FOV, Aug 13, 2017.

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  1. KD4FOV

    KD4FOV Ham Member QRZ Page

    I have a FT-1000D I recently purchased used.
    The radio is fully functional and has the 2.8KHz Inrad filters on the tx path.
    Originally my audio bandwith on TX was pinched up with a bandwidth of 200hz to around 1.7KHz.
    I found a page that detailed some cap changes on the input the audio chain which I performed.
    This help quite a bit but it was still pinched.
    I adjusted the carrier offset adjustment now I get 80Hz to around 3000Hz, and it sounds wonderful.

    The only problem that remains is the SSB power output.
    On a peak reading bird and a SDR using a seperate antenna and the Yaesu meter all three agree that my max output is around 100 watts. On FM and CW I get the full 200 watts out.
    When I work JT65 I can get the full 200 watts out.
    Using a mike on SSb with the ALC within it's range I can only get 100 watts out.
    Watching the meter is evident that some circuit is throttling back the power, most likely the ALC circuit.
    I don't have the service manual so I'm asking for help and/or advice.
    Anyone have any ideas?
  2. K9STH

    K9STH Ham Member QRZ Page

    I have the FT-1000 Mark V service manual in PDF format. However, I do not know how close this is to the FT-1000D. If you can use this, then contact me at the following E-Mail address:

    k9sth (at) sbcglobal (dot) net

    Glen, K9STH
  3. WC5P

    WC5P Premium Subscriber QRZ Page

    See mods.dk website for the service manual for the original version of FT-1000.
  4. KA9JLM

    KA9JLM Ham Member QRZ Page

    You run 200 watts on JT65 ?
  5. KD4FOV

    KD4FOV Ham Member QRZ Page

    No I do not run 200 watts on JT65 but it was a test condition, which I'm thinking you knew that.
  6. KA9JLM

    KA9JLM Ham Member QRZ Page

    My mistake. You said that you worked it at 200 watts. Did you not ?

    Many do, Not very good practice and can smoke the finals.

    Have Fun.
    Last edited: Aug 14, 2017
  7. G0GSR

    G0GSR Ham Member QRZ Page

    Will, JT65 is just another audio signal, subject to the effects of ALC, possible audio faults etc.

    What difference is there between the audio feed for JT65 and the microphone?
    Have you monitored the SSB audio? Does it sound OK?

    Frank, g0gsr

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