To recap or not to recap radio?

Discussion in 'General Audio Discussion' started by Shakedown, Apr 15, 2018.

  1. Shakedown

    Shakedown Active Member

    Am I right in saying that these caps I see inside this car radio, are the kind that are not prone to failure?

    This is out of a '75 Cordoba, and sounds like a Russian woodpecker. May need a recap, but was also suggested it could be a dirty ground.

    These caps look to be in good condition, I don't see any PIO's bound to fail early on.

    Last edited: Apr 15, 2018


    Please register to disable this ad.

  2. saabracer23

    saabracer23 AK Subscriber Subscriber

    Salem, Oregon
    Those are all standard electrolytic and are prone to break down and eventual failure, especially in a car environment. Those are nearly 45 years old if the radio came new with the car. I would definitely switch them out if it’s important to keep the radio with the car and you don’t want to purchase a new one.

    maxhifi and DaveVoorhis like this.
  3. nj pheonix

    nj pheonix AK Subscriber Subscriber

    New Jersey
    2 part answer. The caps are past their expiration date and really should be changed.
    My guess (it is only a guess) that won't make it sound better (if one or more of those are shot I can definitely be wrong).
    I would try cleaning all controls with deoxit (not sure what that has , volume, balance, fader.....)
    Also connections where the harness plugs in.
    Even if cleaning connections/controls improves sound quality. For long term reliability the caps you asked about really should go.
    Shakedown likes this.
  4. electronjohn

    electronjohn Plug it in & see!! Subscriber

    Your description of "Russian Woodpecker" (many hams & SWLs will know what that means) sounds like "motorboating"...which usually equals bad cap(s).
    Pioneered likes this.
  5. quaddriver

    quaddriver 120 What's per channel Subscriber

    I have a document I wrote called 'the GM radio project' and it pertains to really any, it goes over basics and repairs etc for car radios. I started the project in concert with an Olds collector because these guys want the original radios in the show cars, and working. I wrote it with the casual DIYer in mind - guys who are not afraid to rebuild a 40+ year old motor, might have the moxie to do a radio. PM me an email address and I will send it. Its a work in progress, and will be added to as customers send me stuff (working a wonderbar right now geesh!)
  6. Bob

    Bob AK Subscriber Subscriber

    West coast
    since these have been rattling more than filllings at a death metal concert, reflow all the solder
    joints and replace any caps older than a middle school graduate.
    EngineerNate and Pioneered like this.
  7. teal'c

    teal'c It's all moo

    Michigan, N of Detroit
    That means nothing.
    beat_truck and woodj like this.
  8. arts

    arts Super Member

    Qc, Canada
    First car I ever drove was a '75 Cordoba with a full load,400cid/4bbl/dual exh:) That damned thing could pass anything but a gas station!! I wish I had it today:(

    Re-capping that radio would likely put everything right,and is probably a necessity by now. I hope you are adept at disassembly and working in really tight spaces though....
    Shakedown likes this.
  9. Shakedown

    Shakedown Active Member

    Oh man Yup! This one came out of a blue '75 400 dual white interior, that I bought on the Vermont and Canadian border.

    Radio is the rare 8-track that has FM & AM, I'd really love to save it.

    Right now it's making a knocking sound and by other members on here that equates to bad caps.


    Please register to disable this ad.

  10. Shakedown

    Shakedown Active Member

    Here is the other problem I ran into, the tuning chord is really worn out and ended up getting stuck when I took it apart and cannot get it back.

  11. Shakedown

    Shakedown Active Member

    Okay I'm writing down all the caps I need for the radio, and I came across these ceramics with odd lettering and numbering.

    The rest of the orange caps read out as .02UF, but these two right here read out as follows.

    Left cap: 15

    Right cap: 1st line: 473Z 2nd line: 56

    Much help appreciated!

    Last edited: Apr 16, 2018 at 1:54 PM
  12. RTally

    RTally AK Subscriber Subscriber

    That is a ceramic disc cap. Those do not suffer age-related degradation like electrolytic caps. You should not need to replace any ceramics unless there is physical damage to the cap.
    Shakedown and Bruno Primas like this.
  13. toxcrusadr

    toxcrusadr AK Subscriber Subscriber

    Central Missouri
    Yeah, someone said "all of those are electrolytics and prone to failure" but it's clear there are some ceramics in there that don't. Maybe some films too. Concentrate on the electros first.

    Ah, how about an alignment? Although I suppose you'd want to recap first. It may improve things quite a bit. Only problem is FM alignment is not that easy to do. Do you have a SAMS or other service manual on this beast?
    Shakedown likes this.
  14. ev13wt

    ev13wt Super Member

    That looks like a task. Wow.

    Get a little mount or monkey grip, mount a camera a bit up - off to one side.

    Take pics. Lots. You will need them :)
    Bonus, you could make a high speed build video out of it.
  15. quaddriver

    quaddriver 120 What's per channel Subscriber

    gimme the model number, I got a ton of sams AR series for the shop....(ar = auto radio)
    Shakedown likes this.
  16. gadget73

    gadget73 junk junkie Subscriber

    Southern NJ
    A friend of mine had a '77 Cordoba with the 400. The lean burn had been removed and it was definitely a pig, both in terms of performance and fuel economy. That ThermoQuad did sound impressive when it was opened but that was all you could really say for it.

    but yeah, you're probably due for a new belt on the 8 track, new electrolytic caps, some solder re-flow, and some TLC to whatever the tuning mechanism is. Most of them are gear drive or use a friction plate but there is probably some lube in there that is dried up. If its got a string, those can stretch or break. Some use the string just to move the needle.

Share This Page