How to clean a tuner (analog)

Discussion in 'Tuners' started by dr*audio, Jan 17, 2008.

  1. Ray Gianelli

    Ray Gianelli Well-Known Member

    Messages:
    512
    Location:
    Lake Worth, FL
    About 2 years ago I posted a thank you to Warren for this sticky. The unit I was having issues with was also a TU-717. Noisy when moving the tuning capacitor.
     
  2. onwardjames

    onwardjames Hoardimus Maximus Subscriber

    Messages:
    14,869
    Location:
    Kentucky
    Thanks to this thread, I was able to clean up and improve a lowly SX 3400 Pioneer. The baby of the 1980 lineup. She's singing sweetly now. No locomotive rumble anymore.

    However, my SX3700 (also acquired the same day as the 3400) which should have a far better tuner, WILL NOT lock onto anything in stereo. Mono, it'll do okay, tho the 5 lights for signal strength don't budge, or at least don't light up (local NPR station, which is usually maxing any signal meter, hits 2 out of 5).

    The "stereo" light doesn't come on, even when in stereo (which I can only pick up the NPR station, not a single other one) and so I don't know if its burned out or what. On my old 7065, when the stereo bulb burned out, it wouldn't go into stereo mode. Odd, yeah, I know. Replaced bulb, stereo once more.

    The 3400 is KILLING the 3700. I've cleaned it a couple times, but still no "stereo" light, tho it does light up "FM LOCK" on the NPR station.

    Another cleaning, or something that needs a tech? Thanks, Warren, for your fine thread.
     
  3. Lesterbest

    Lesterbest Super Member

    Messages:
    1,602
    Both tuners are long in the tooth. The 3700 needs an alignment. You caught a break with the 3400. You're batting 500. Not bad for >35 yr old tuners.
     
  4. onwardjames

    onwardjames Hoardimus Maximus Subscriber

    Messages:
    14,869
    Location:
    Kentucky
    Damn. I know of no one who can do this. Thanks for the help, tho, Lesterbest. It's the dual analog/digital tuning that attracted me to the 3700. I mean, it'll hardly pick up anything with the stereo switch engaged.
     
  5. rmunson

    rmunson console destructor

    Beeswax to the rescue for my tuner string! There was a place on the dial string that was worn and slipping -- I applied beeswax to that area of the string - as well as the rest of the accessible length of the tuner string - working the dial back and forth, the string started to grab where it previously spun/slipped --

    hopefully this trick will serve -- would it be advisable to replace the tuner string with new dacron string?
     
  6. alexanick

    alexanick New Member

    Messages:
    1
    Hi draudio, I'm Ken and I'm in the Cleveland area also. Mayfield Village to be exact. Here's the problem I'm having. I have a Nikko 7075 tuner since 1978. I started having a problem where the one speaker would cut out. If I turn the volume control up (loud), it would come back on. If I turn it down to a comfortable setting it would cut out again. I have taken it to two different places already, both of which "fixed" it, only to have the problem come back a week or two later. Both said it was dirty, one I believe, replaced it. Any experience with this problem.
     
  7. Don doner

    Don doner New Member

    Messages:
    5
    Location:
    North hills , Ca
    Hi there I'm new here, I just acquired a Bose 1801 amp, Bose 4401 pre amp, Bose 550 receiver and 4 series 2 Bose 901 speakers, I have no clue what I should do with this stuff, is it worth keeping? And trying to getting working?
     
  8. onwardjames

    onwardjames Hoardimus Maximus Subscriber

    Messages:
    14,869
    Location:
    Kentucky
    Hello, and welcome to audiokarma.

    First, you should start your own thread about this very nice acquisition. Bose has its haters, but what you have is actually some rather desirable gear, especially the amp and pre.

    If you list where you are, I'm sure there are some AK'ers around here who might stop by and help you hook it all up. Since I don't know your skill level, I would suggest pics, and also perhaps a rundown of where you got it, what issues you're certain about, etc. Tell us a bit more, but definitely start your own thread, perhaps in the "General Audio" section.

    Best of luck.
     
  9. Don doner

    Don doner New Member

    Messages:
    5
    Location:
    North hills , Ca
    Thank you very much, I bought all of it very reasonably, I think it came out of a Stereo Shop in Canada, I have the original invoice from Bose along with the Original Ads for each piece , Shipping was more than what I paid for all of it do too the weight, As soon as I find my way around AK I'll post some good pictures.
     
  10. Jack Tietjen

    Jack Tietjen New Member

    Messages:
    12
    How do you align a tuner. Is it something a pro needs to do or can the average person do it?
     
  11. Lesterbest

    Lesterbest Super Member

    Messages:
    1,602
    Aliignment is a job for pros. They have the pricey test gear needed to do it properly. In addition you need experience & expertise. Bite the bullet, & pay a pro. Otherwise proceed @ your own peril.
     
  12. Alfonsol

    Alfonsol Active Member

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    265
  13. audiodummy

    audiodummy Active Member

    Messages:
    101
    How often do stations transmit monaural on FM?

    If the only station I could receive where I'm at was NPR, I'd never know if my stereo lamp was working or not - this FM NPR station only transmits monaural and does not transmit stereo multiplex. It is one of the stronger stations in my area and I know some of the weaker/farther stations do have stereo so it was weird that I can only conclude this NPR station does not transmit stereo (nor does it need to!)

    BTW, those tiny tuning variable capacitors ...well I'd be very worried about disassembling them. I think to get the capacitance up in such a small space, this variable capacitor has sheets of dielectric instead of just using air.

    I've only seen this type of cap in portable radios. The tuners I have use larger, air dielectric tuning capacitors, then again they are old...
     
  14. amptramp

    amptramp Active Member

    Messages:
    354
    Location:
    Mississauga Ontario Canada
    You can use fishing line as long as it is not monofilament to replace a dial cord. I have done this successfully on several tuners and radios.
     
  15. Greyrat

    Greyrat New Member

    Messages:
    27
    Location:
    Cleveland, OH
    I have a Scott 380R receiver that has had scratchy FM reception up and down the dial since I acquired it about 10 yrs ago. Pretty bad and hard to just overlook. A couple of years ago I tried this procedure and took a conservative approach - very cautious with the non-residue CRC spray, and very very cautious with the faderlube. Not much of an improvement - if any at all. So it got to the point where I felt I needed to get the FM reception working to my liking or sell this receiver. Blocked out 2 hours today, setup in the garage with the supplies and went at it with a more aggressive approach. Sprayed the contacts several times with CRC spray. What green residue would not come off the contacts - I used a plastic toothpick to scrape off. Also used 91% isopropyl on a Q-tip to remove any remaining green oxidation. Finished off with spraying faderlube into the shaft of an eye dropper that I had pointed at each contact - a good 1-3 drops were placed (tried to walk the line between getting faderlube applied but not too much). Waited a few hours hooked her up - 100% improvement. No more "outerspace" sounds when I move the dial on FM reception, good solid signal reception. I wouldn't recommend being aggressive on this type of issue for all situations - but it certainly corrected my FM tuning issues.
    Thx. for the tip Dr. Audio.
     
  16. dr*audio

    dr*audio Fish fingers and custard! Subscriber

    Messages:
    18,009
    Location:
    Cleveland, Ohio
    Sometimes you have to use alcohol and an acid brush or toothbrush to get the more stubborn oxidation out. Years ago my dentist gave me a small pointed toothbrush that you are supposed to massage your gums with. This works great for cleaning tuners!
     
  17. Dave1384

    Dave1384 Stuck in the 70's

    Messages:
    3,041
    Location:
    Suburban Philadelphia
    I have 2 Pioneer sx 780' s . One restored. FM stations line up on the dial fine. AM is another matter. Am 56 is ok. 77 , the dial pointer is on 800. 990 am , the pointer is near 1100. 1210, the big 50000 watter is up near 13. How can this be fixed?

    Do I need to fool with a trim cap? What do they look like ? There are 4 screws on top of the fins.
     
    Last edited: Aug 13, 2017 at 8:19 PM
  18. dr*audio

    dr*audio Fish fingers and custard! Subscriber

    Messages:
    18,009
    Location:
    Cleveland, Ohio
    Download the service manual and follow the part of the alignment instructions for AM that say "tracking."
     

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