SX-1010 Tuner Question

Discussion in 'Tuners' started by ZeroJunk, Dec 15, 2016.

  1. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

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    Mine has lost most of the receive signal strength . I thought it was an antenna problem and bought a new yagi and feedline. Didn't help. Tried an external tuner and it pegs the needle on several stations. The SX-1010 will only receive a couple of super strong stations.

    But, the quality of the sound on the stations it will receive is great.

    So, I'm thinking this is not an alignment issue. I took the service manual and tweaked a few of the adjustments and it didn't seem to have any effect on signal strength.

    The upper core of one of the pots is stuck, cannot be adjusted, and will need to be replaced.

    That brings me to the dilemma. I have rebuilt most of this receiver, but it is cosmetically a pig.

    If it needs a lot of work it may well cost more than it is worth, or more than you can buy a good separate tuner for.

    But, if it is simply in the alignment it would be nice if it worked. Sounds better than the F99X I have on it now.

    Any advice ?
     
  2. Lesterbest

    Lesterbest Super Member

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    "So, I'm thinking this is not an alignment issue."

    Au contraire, this sounds very much like an alignment issue. This is not a DIY job.
     
  3. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

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    I'm not knowledgeable about this at all. But, it happened fairly suddenly which is why I was thinking something may have failed.
     
  4. avionic

    avionic " Black Knights" Subscriber

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    It most likely needs and alignmemt now.
     
  5. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

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    I have no doubt about that. But, it had gotten pretty unuseable as it was.

    I was trying to determine if the adjustments in the service manual had any effect on signal strength. They did not.
     
  6. rcs16

    rcs16 Super Member

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    You really should be saying exactly what you adjusted. so all you have accomplished, is making it more unusable.
    the manual states you need the required equipment to do any adjustments, i guess you forgot to read that part.
     
  7. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

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    I don't know what is complicated about my post. I am not trying to fix it, nor am I capable of fixing it.
    I was trying to see what effect the alignment procedures had on the signal strength so I could post it on here and see if anybody could determine from that some idea of what might be involved.
    The problem is no signal strength. The one or two stations it will receive sound great.

    The question is whether to send it out for repair or just use an external tuner.

    I don't mind spending a couple of hundred bucks, but don't want to spend much more than that.

    So, it matters whether it is an alignment issue or something more involved.

    Could be that what I have posted doesn't tell anybody anything.

    Which could well be the case. But, I thought I would give it a try.
     
  8. 91r100gs

    91r100gs Addicted Member

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    In much the same boat as you in regards to "Is it worth it" My decision is about a TX-8500II. Works great, sounds great, I use it once or twice a week every week. This tuner is almost 40 yrs young. The only thing out of sorts is, it needs to be powered up for about 15 min, to achieve the full signal strength, that the station would normally acheive. I would spend about $200 to rehab this tuner which I paid $250 for in 1978. Like the OP I think it would be more than $200. Shipping this would use up about half of the budget. Something in the gut tells me it be $350+
     
    Last edited: Dec 15, 2016
  9. Lesterbest

    Lesterbest Super Member

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    To minimize shipping costs, I'd look for someone close as possible to Browns Summit who is capable of aligning your tuner. Somewhere there are NC audiophiles who can help. Even if you live in an audiophile igloo, I can't justify $350 incl shipping. Good Luck.
     
  10. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

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    Thanks man,

    I'm taking it to Ctech Electronics who sells alignment service on eBay. They are maybe 15 miles away. Let you know how it turns out.
     
  11. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

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    OK. Ctech finally responded today after three months and said that there was more going to be involved than a simple alignment. I was 90% sure of that from the start. Estimated cost at $ 400 with the disclaimer that they may not be able to fix it at all. Wanted $225 down if I choose to repair or I can pick it up paying a $90 bench charge.
     
  12. rcs16

    rcs16 Super Member

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    Fatal mistake, messing with the quad coil
    What is complicated is that you messed with something that you have no idea how to adjust or repair. You need test equipment to adj and troubleshoot a FM tuner. It is clearly spelled out in the manual. Without T/E you are just messing it up further. If you told Ctech that you were messing with it, maybe that is why they want to charge you an unreasonable amount.
    Wow, 3 months to tell you this. I am pretty sure someone could fix it for a lot less, but shipping is a big cost and makes it totally uneconomical.
    So are you going to give them the $90 or tell them they can keep it?

    Good luck
     
  13. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

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    What is uncomplicated is that it was broke before I messed with it.

    The signal strength went to nothing before I messed with it. Suddenly.

    Pretty obvious that something failed.

    Listening to you and the others cost me $90. And, I should have known better.

    I bought a TX9500II which works fine.
     
  14. rcs16

    rcs16 Super Member

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    B.S. I never advised you to take it to anyone let alone to Ctech. All I asked is exact what you messed with and you could not even give me a straight answer, knowing what you did is wrong and I want to let everyone else know to not repeat what you did.
    Sorry for your loss of $90 but do not blame me, all I was trying to do is help you. I should know better with many of the thankless folks on this site. If you were not so impatient, I could have helped you possibly fix the tuner. I do this for many others on AK since many, including you, have no clue how to repair a tuner.
    Good luck with your TX9500II, it might very well have the same fate as your 1010. These devices are old and can fail at any time. It is a crap shoot, some you win some you lose.
     
  15. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

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    I asked a simple question and you went off on a tangent . The tuner died. Period.
    I had another SX-1010 and the signal strength would vary just by jiggling the board. I was simply trying to see if the adjustments outlined in the service manual had any effect. They did not. Pots get old and can lose continuity and sometimes turning them slightly and back will have an effect. It did not. It was never an alignment issue to begin with. And, it isn't now if I knew which component failed.
    Markthefixer went through some procedures in a thread I found later that explained some methods to check for component failures in the tuner. That is what I was looking for.
    Even Mark doesn't do alignments, but he can tell you which components may be suspect and how to check them.
     
  16. rcs16

    rcs16 Super Member

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    Really, maybe I can teach him how, it ain't that difficult if you have the necessary equipment.
    I can still help you, I have not given up on you.
    You have to figure out where you are loosing the signal. It could be in the RF front end or in the IF strip. You can use the mtf finger trick to see if the signal gets lost through the ceramic filters or in the HA1201 IF amps. You can couple the IF signal from the IF i/p directly to or around each ceramic filter and/or IF amp(HA1201) into the HA1137 chip, use a 10nF cap to couple the signal.
    You can verify that the RF FE is okay, by using another tuners IF section. Use a section of coax to couple the signal. center conductor for sig and shield for ground. on one end has to be grounded. Always best to couple through a 10n cap to isolate DC.
    You can use another tuners RF FE to provide the signal to the dead 1010 IF strip to verify that as well.
    Do you understand what I am saying?
     
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  17. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

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    Thanks man. I printed this. It would be nice if the tuner in the SX-1010 worked. I got the SA9500II as well and can use that . May be a few days because I have a pretty big back log in the shop (outdoor power equipment). And, I understand what you are saying although I will probably wander around a bit finding the test points.
     
  18. rcs16

    rcs16 Super Member

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    The TA-9500 II is a bit better tuner, but I am sure you want to fix the tuner in the sx-1010 as well it is a good tuner.
    To bad you did not post in the pioneer section, more people top help you out and for others to learn from. mtf only participates in the pioneer forum. could ask for this thread to get moved. PM xpunker, he may help get it moved.
    It should not be to difficult to fix it, it is one of the easier ones.
    Does not hurt to read up a bit on the operation and print out the schematics nd the pcb component drawings.
    Do you have a DMM? Know how to use it?
    I am also helping some one fix there tuner in a sx-1980, way more fun, but the same procedures to follow.
    Do you have the proper nylon alignment tools, you are going to have to check the quad transfomer and see if you brought it out of alignment. Digikey sells them
    243-1016-ND
     
  19. ZeroJunk

    ZeroJunk AK Subscriber Subscriber

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    Location:
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    Thanks for the part number.

    I have it on the bench and here is what it is doing

    On just a couple of pieces of speaker wire for an antenna in my basement it receives nearby stations perfectly. Only thing is that it only shows a little less than S1 on the meter with the meter trimmer adjusted to max. Another SX-1010 was in the black on several of those stations with the same set up.

    It shows Stereo and I can tell it is Stereo on the headphones on stations which show no deflection of the S meter at all.

    On the stations that are strong enough to show some meter deflection the center tuning meter aligns perfectly with center of distortion free reception.

    It acts like you turned on a 20 dB attenuator or something.

    Confused as usual.



    I suppose it is possible that it is just a problem with the meter driver and I am just an idiot.
     
    Last edited: Mar 16, 2017
  20. rcs16

    rcs16 Super Member

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    2,633
    Location:
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    You can measure with the DMM, DCV, the o/p of the signal drive pin on the HA1137(Q3,13) and compare against the good unit.
    If you compare the stereo noise from the good unit to the bad unit, do you hear the same noise level, if so it is just a meter issue and the signal into the HA1137 is just fine.
     

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