Tempo One problems

Discussion in 'Radio Circuits, Repair & Performance' started by N9ZGA, Feb 21, 2021.

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  1. N9ZGA

    N9ZGA Ham Member QRZ Page

    Were do I start

    I was lucky enough to purchase the radio I made my first ever HF contact with. It was back in 1994 when I was in highschool and the contact was 40 meter CW. Well the radio needs some work.

    When I first purchased it maybe 10 years ago it was not working and I was really close to getting it up and running. It sat for a long time and now it is worse.

    When I first turned on the rig last night I got static out of the speaker. The S meter went up all the way and slowly came down while the tubes warmed up. While I had static I did not hear anything else. Now I have no static at all and the s meter does not work. I tried putting a signal into the rig with my signal generator but did not hear it.

    Where do I start???? I hate this!! I have all this test gear and I have no clue what I am doing with it or how to fix a radio!

    I look at the schematic but have no clue where to start and what the voltages should be. How do I know if parts are good while installed in the circuit if I don't know what the voltage should be??? I want to learn this stuff so bad but get so frustrated when I have no clue what to do. I hate starting at the bottom but I have to start somewhere.

    Thanks for reading and 73's

    N2HUN likes this.
  2. W5RKL

    W5RKL Ham Member QRZ Page


    You said you hate to start at the beginning. I mean no disrespect but unfortunately, Andy based on your lack
    of electronic knowledge and troubleshooting skills using the test equipment you have and the inability to read and
    understand a schematic puts you at a complete disadvantage. Attempting to repair your Tempo One on your own
    by asking a few questions, can lead to more problems in your Tempo One than you already have. I recommend you
    find a local ham who has the knowledge and skills to sit with you to help you repair your Tempo One.

    Mike W5RKL
    WA9SVD, N4FZ, AI3V and 1 other person like this.
  3. N2HUN

    N2HUN Ham Member QRZ Page

    Tempo Ones are my favorite rigs, had three over the past 45 years. The one I have now I bought used, realigned it, changed problematic caps so I know a little about them. It was a "smoker" so the contacts were especially tarnished and dirty from being in a smoking environment. Smoke gets everywhere inside a radio.

    I'm not an expert though, just a tinkerer with experience. Hopefully others will chime in.

    The fact that the S meter comes down after warm-up is normal.

    There are a few things you can do that are simple and good first steps. Do these with the radio off and unplugged!

    Get a copy of the manual (free on-line). Look it over if you haven't done so. Look over the photos and diagrams of the unit and see where the controls are located.

    Clean all the switches and control pots with a good electrical cleaner such as DeOxit. You'll have to remove the radio from it's cabinet to do so.

    From what you state, the radio was sitting around idle so I would do the above first. If it was in a smoking environment during it's life then cleaning all the contacts is especially important. Let us know how things go and also go on-line and search under Tempo One for useful information.
  4. HAMHOCK75

    HAMHOCK75 QRZ Member

    I bought my first Tempo One last year for restoration. N2HUN is right about the S meter. It swings to the right, then recovers when warmed up.

    I might be lucky but it didn't work, no receive no transmit, but 100% of the problems were just dirty contacts. There are a few relays that control almost everything and the oper-rec-cal switch is notorious.

    I wrote up one of the more interesting cleaning jobs that caused the audio to disappear.


    Aside from all the cleaning, the unit still had the original finals from 50 years ago and they still put out 100 watts on all bands but 10M
    N2HUN likes this.
  5. G3YRO

    G3YRO Ham Member QRZ Page

    When these rigs were stil a current model I used to work for Yaesu (who made these rigs - they are really an FT200)

    I agree with other comments . . . you really need a reasonable electronic knowledge to suss out faults on a rig like this . . . plus being mainly Valve, you are dealing with fairly high HT voltages on the various stages !

    However . . . it may be something as simple as a dirty switch that is stopping it working . . . so get an aerosol can of decent combined Switch Cleaner/Lubricant and spray it in/on the various pots and switches, then give each a good back and forth action.

    The most obvious dirty switch that would stop it working is the VFO switch - marked RX EXT - NORM - TX EXT . . . so try that one first.

    Good Luck !

    Roger G3YRO
  6. K5DH

    K5DH Ham Member QRZ Page


    If you only have the schematic, you won't get far. Obtain a good, clear copy of the complete manual (grab an original if you can find one). The manual will contain valuable troubleshooting information.

    Take @G3YRO's suggestion to heart. Dirty switch contacts are a very common ailment with vintage gear, and cleaning the pots and switches will be beneficial. Another common problem is corrosion in the tube socket contacts. Remove each tube, lightly dress the pins with a soft, brass-bristled wire brush. Use DeOxit D5 and a thin, pointy-tipped cotton swab to treat each contact in the tube socket. Seat and re-seat the tube a few times to burnish the contacts. Do this for each tube, one at a time. You should be able to find a suitable brass brush at your local Ace or True Value hardware store. Gun shops and shooters' supply houses will have the cleaning swabs, or buy them off eBay like I do. You can buy DeOxit off eBay and probably Amazon.

    As @W5RKL suggests, try to find a local ham who's experienced with troubleshooting vintage tube-type gear, and ask them for help. Have them work with you and "show you the ropes". Ask lots of questions along the way, because that's how you learn things. The QRZ.com braintrust is also here for you. Troubleshooting an old rig and bringing it back to life is very rewarding and satisfying. But don't try to go it alone.

    Remember that there is very high voltage exposed at many places within the rig's cabinet. Use great caution. Death is a permanent condition.
  7. N9ZGA

    N9ZGA Ham Member QRZ Page

    Thanks for all the replies. As far as the relays are concerned it is normal operation for the 2 relays on the bottom of the rig to latch upon power on? The relay on the top side of the rig only latches when i put the rig into transmit mode with the calibrate operate switch on the bottom right of the face panel. I have not tried a mic or key on the rig yet.

  8. G3YRO

    G3YRO Ham Member QRZ Page

    No, none of the Relays should latch until you switch to Transmit.

    Roger G3YRO
    N2HUN likes this.
  9. N9ZGA

    N9ZGA Ham Member QRZ Page

    That's what i thought. Thanks for confirming

    N2HUN likes this.
  10. HAMHOCK75

    HAMHOCK75 QRZ Member

    If you have a problem with the oper-rec-cal switch, it turned out not to be the contacts on mine. These four screws loosened so the contacts could not touch.

    There is blue Loctite ( or the Japanese equivalent ) on the back side but the Loctite didn't hold.

    The knob on the lever switch is not pressed on, it unscrews counterclockwise.

    WD4IGX likes this.

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