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  • #15335
    Forum Participant

    Hi everyone-

    I just joined these forums and am hoping to get much more familiar with vintage radio restoration. Glad to see that there’s a small but dedicated community to this craft.

    I recently acquired four70s/80s era vintage radios. But I made the big mistake of plugging them in to test them once I brought them home (gasp). According to this website I was NOT supposed to do that.

    I didn’t hear any pops or smoke. Thank goodness. But I’d really like to bring these old beauties to some form of workable function.

    Here’s what you see in the photo above:

    Panasonic R-1042: Hums when plugged in. But nothing else
    Sharp FW-416C: Powers on and hums but nothing else. Tuning band not working at all.
    Sony ICF-9740W. Works, but makes loud popping noise anytime volume knob is turned.
    Holiday LL-36749 – Works but very loud crackle when adjusting volume knob. Crackle distorts audio when turned. Broken antenna

    I have a few questions:
    1) Is that radiola guy correct in saying that I might have screwed them up by plugging them in to test them?
    2) What’s the best and safest way to properly test these radios?
    3) Can they be rescued?
    4) If so- what’s the best credible, no-BS resource for learning about vintage radio repair?

    CVRS Member

    Hi MrWrench
    Would not be concerned about “screwing them up” by plugging them in, as they do not work now and need repair anyway, But the safest way is to use what is called a “Dim Bulb Tester”. Basically its a Incandescent light bulb, usually 60 Watt, put in series with the item under test and if there is a short within the radio the bulb will turn on full brightness, if there is no short and basically in decent shape the bulb may turn on just Dim or may turn on bright for an instant and then slowly go to Dim. Do an internet search for Dim Bulb Tester for complete instructions and how to build one, its a very handy item for the test bench and can save you a lot of fuses and other problems.
    As far as being Rescued, that all depends on the owner and how much they wish to spend as far as parts are concerned and time, most anything can be rescued. Even if some parts need to be machined it can be done but there is a cost factor as well. but the choice is by the owner
    As far as the best source for learning….hard question to answer but there are a lot of You Tube Videos which are excellent but also some which are total nonsense, also electronics online courses, but keep in mind that anything with TUBES …. Transmitters…..old TV’s and similar items have LETHAL VOLTAGES inside and extreme care must be taken as DEATH can be a touch away. I had an Audio Amplifier brought in for repair (tube unit) and it had not been turned on for at least 6 months I was told and when I put it on the bench the power supply capacitors still held a full charge of 350 Volts DC which really was not expected but I checked it with a voltmeter before touching it, these particular Capacitors did not have what is called a Bleeder Resistor on them, I did install them for safety purposes.
    Now the transistor items and battery powered items are not as dangerous but all electricity has its own hazards and best to avoid any shock but we do on occasion find ourselves getting a shock even when experienced with electrical work and when that happens we Learn from it ….Hopefully !
    There are also many publications covering electronic repair/work, home study basic electronic repair courses are offered by some company’s, ask questions at a local electronic repair shop etc….

    Hope this helps

    John Greenland
    CVRS Member


    from your comments , I would suggest that you first deal with the 2 units with noise.

    It would seem that it is very likely a volume control problem which might be alleviated with a proper electronic cleaner spayed into the actual control or worse case a replacement control.

    If you can get these 2 units working then you can consider if you wish to repair the other units .


    John G. VO1 CAT

    Dan Walker
    CVRS Member

    If you are looking for information about how to repair these old radios i suggest reading ;;The elements of Radio” by Marcus and Marcus.
    It is a very good book written in layman’s terms, and leads you through how a radios works,giving very good information
    Dan in Calgary.

    Ralph Spracklin
    CVRS Member

    Hello All
    Exactly what I was thinking John. And yes indeed, Dan’s suggestion of studying “The Elements of Rado Serviving” is a great idea. I have learned much there.
    See the link below, it is on-line on the “World Radio History Site”. And if you are really interested in getting into this great Hobby, A dim bulb tester is a great start, also an Isolation Transformer can save one from personal injury or even ones life. There is much written on-line on the subject o “Safety”. Also a reasonably reliable Multi-Meter is a must, and this does not have to be a high priced FLUKE, although I myself wish I owned one.


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