TX-7800 frequency not right

Discussion in 'Pioneer Audio' started by E100, Oct 12, 2017.

  1. E100

    E100 New Member

    Messages:
    25
    Hi. TX-7800 displays FM frequency slightly off. I see a radio channel that is broadcasting at 100.8 on 101.2 Reception is good and stereo/locked are on. What could be the problem?. Thanks.
     
  2. rcs16

    rcs16 Super Member

    Messages:
    3,057
    Location:
    Baldwin, Ontario, Canada
    An alignment or take tension off the dial string and move the pointer to the correct position.
     
  3. E100

    E100 New Member

    Messages:
    25
    Thanks for reply. How to do it? Any instructions available?
     
  4. rcs16

    rcs16 Super Member

    Messages:
    3,057
    Location:
    Baldwin, Ontario, Canada
    The adj procedure is in the manual but you need special equipment for that.
    I do not know this unit very well, but if it is like others, there is a tension spring in the tuning wheel attached to the var cap. Problem can be you unravel the string which is a PITA to put back. You can make a note of the dial string the way it is put on if you mess it up. You can put some tape around the tuning wheel so that the string does not unravel form the wheel, The pointer is attached to the string through some stranin reliefs, the string has to be taken off the point to move in the direction to re-cal it against the dial. None of this is easy, it takes some practice.
     
  5. larryderouin

    larryderouin You can be sure if it's Westinghouse??????? Subscriber

    Messages:
    20,153
    Location:
    Glen Burnie Md.
    Check your AM BAND before doing anything. Changing the needle position to accomodate the FM Band will cause the AM Band to be off. Most manufacturers have you turn the tuning dial all the way to the left until it hits the stops and note the Dial pin location (should be on ZERO on the LOG SCALE). If it's offset you need to loosen the strain relief's on the Dial pin and move the pin to match the LOG SCALE at ZERO. THEN do the alignment on both bands. If you never plan on using AM, you can check the dial pin location and adjust as necessary, then align the FM band. If it's anything like the TX-6800 the adjustments are made with a wooden spud and either opening or closing the fins on the Variable cap, @ 90mHz, like a SX-780. PITA for a good tech who knows what he's doing, almost impossible for a DIY. I'd just move the dial pin slightly left and call it a day.
     
  6. E100

    E100 New Member

    Messages:
    25
    Many thanks. I will try to move the pin slightly left.
     

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