Yaesu FT101EX... where should I start looking for these 2 problems?

Discussion in '"Boat Anchor" & Classic Equipment' started by KD0YSX, Sep 17, 2021.

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  1. N3RYB

    N3RYB Premium Subscriber QRZ Page

    More thoughts on this, if you can't hear the BFOs running and want to rule out the mode switch, you can ground Pin 3 on the Mod/Osc board to turn LSB on, if you get output then, its likely your mode switch. Mine acts a little wonky too, even after being cleaned.

    If you still get no output in LSB/USB mode even when forcing it on by grounding the Pin, your next suspect would be the IF board(AM does not go through this board). Nice thing about the FT-101s, replacement boards are easy to come by! I think I have a few spare IF boards about here.
    Last edited: Oct 29, 2021
  2. W5UAA

    W5UAA Ham Member QRZ Page


    I was hoping you were going to finally have a good working 101EX. It was a great radio in its day.

    When I was a teenager, my mother finally realized what that exposed voltage on my home brew 6L6 was and convinced my father to buy a brand new 101EX. He got his ham license (again) and we both used it. It was a pleasure to use given what I had been trying to work with for a year or so.

    It sat up on a shelf in his office for about 35 years, I retired from the Air Force and he gave it to me.

    I went through a series of things similar with my 101EX.

    First, recapped it. Found some crystals were bad and replaced them. I still have the NOS 6JS6C's and the 12BY7 I bought. Didn't need to replace them.

    Bought some extender boards.

    Went through all alignments several times. It received and transmitted well on 20 meters. It put out full power and sounded good on CW/LSB/USB. Progressively worse going up or down in ham bands.

    The LO was putting out barely 1V RMS on 20, progressively less going up or down in the ham bands.

    Tried several times tuning the one slug in that circuit. Could never get it to turn. Tried a heat gun on it and several lubricants on it. I was one moment away from sticking a steel hex wrench in it and crumbling it.

    I put it away for a few months and tried again. I put it away for a few months and tried again. I put it away for a few months and tried again. ... etc.

    After about two years, I finally said the heck with it and practically *gave* it away at a ham fest. One of a couple of old radios I threw a whole bunch of effort and cash at that didn't pan out well.

    The FT-101EX was a great radio put together with parts that were available at the time it was new. Those parts haven't been available for many years. ...especially most of those transistors. The only way to find replacement transistors is to place a bid on a lot of 1,000 or so at a time.

    Sometimes an old radio is just no longer any good any more no matter what. Sometimes it's just scrap.

    Maybe you'll have better luck in a few months.
  3. G3YRO

    G3YRO Ham Member QRZ Page

    None of the components are hard to come by for the FT101 (including the Transistors, as none are critical) so it's a very easy rig to keep going.

    Quite apart from the fact that device failure is extremely rare in these rigs - my own FT101E that I bought new when I worked for Yaesu has never had a single fault !
    If the Carrier Oscillators weren't working, he wouldn't hear anything on Receive . . . so they obviously are.

    These rigs are VERY easy to diagnose faults on, just by the symptoms. And you rarely even need Extender Boards, as it's usually obvious what the fault is. (We obviously had Extender Boards when I worked for Yaesu . . . but to be honest I never used them)

    Roger G3YRO
    N3RYB likes this.
  4. G3YRO

    G3YRO Ham Member QRZ Page

    You should never touch ANY of the slugs in the RF or LO tuned circuits . . .

    All the alignment is done by tweaking the Trimmers for each band.

    Roger G3YRO
    N3RYB likes this.

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