Thursday, December 17, 2009

Update: Olympic model 6-606

This is the most challenging radio i have attempted to restore. I
now have AF coming out and i can tune in lots of AM stations. But,
the audio remains distorted. It is even distorted when i turn the
volume down all the way.

Very strange. I am running this by enthusiasts at
to see what the pros think.

Lots of fun though!! Stay tuned for more....


  1. Is this distortions happens before the AF stage? You can to disjoint link from the detector and check separately AF amplifier with another source.. It seems like I'm saying common and well known things :) I'll stay on the wave. dit-dit.

  2. Good suggestion. After reading your post i tried that. It buzzes alot if there is no connection to the detector. Which is not what i expected. I think the power supply is suffering from alot of ripple, even though i have replaced all of the supply caps.

    Here's the thread from antiqueradios:

    The radio is sounding much better now compared to what it was. I need to relax on it for now and think about what is going on. Very interesting stuff, certainly a challenge compared to other radios i have worked on.

  3. Thank you for the link - I never seen that before. So, what is your current situation? Is it pure Happy End?

    NB. usual steps was as follows:
    1. Check joints and wires
    2. Check DC voltages at control poits according to the manual.
    3. Starting from the last audio stage disjoint cascades and check sound using sinewave source. Power amp, then power+preamp, then detector+preamp+last (using 455kc modulated signal) etcetera. Input should be connected to the source via the capacitor and resistive T-circuit (and neither buzz nor hum, pleasure for your ears ;).

    It's nearly impossible to find a distortion source in the RF stage, but I can imagine such situation too.

    4. Make some mysterious scientific passes using a hot Iron.
    5. Take a sit near the X-mas Tree with your WORKING receiver and listen corals.

    Good Luck!

  4. Got it working. It was the speaker.

    I had to get an isolation transformer, then inject a signal with my signal generator, probed it all the way through the circuitry.

    Turns out it was the speaker that is the cause of the distorted audio.

    I will post a web article once the restoration is complete. Thank you for your advice with everything. Much appreciated. These old radios can be very challenging.


  5. Oh, sorry, I missed your answer.Glad to hear that you did it, it's nice to listen to Christmas songs using such very new radio, thought. Good luck.