Old Regency Whamo 10 Scanner Project 2 Mhz Off Frequency (Stuck on this)

Discussion in 'Technical Repair' started by stevecast2024, Oct 8, 2016.

  1. stevecast2024

    Thread Starter New Member

    Oct 8, 2016
    3
    0
    High folks... My first post here. I've been a looker for a while, now I need some help. If I'm in the wrong section please let me know.

    I'm working on an old Regency Whamo 10 scanner... If anyone remembers these, they were one of the first "Programmable" scanners. These use "Programming Combs" to set the frequency on each channel. You break the teeth off the comb to set frequency. So it turns out that with the unit programmed to 154.415 Mhz, it is actually receiving at 156.415. Looking at the programming sheet we see the following:

    O = TOOTH PRESENT X = TOOTH REMOVED
    Frequency ___ ___
    V
    1 154.4150 XOXOXXOOOXOXOOOOXOOO
    2 156.4150 XOXOXOOOOXOXOOOOXOOO

    So it appears that the issue is with the 6th tooth in on the unit... I have traced this 6th position back to what is called the "Divide by N" board in the scanner itself and down to an IC on that board known as IC512. Looking at the service manual (which is not complete) the voltages are lower then what they are supposed to be on the pin that this line runs to on the IC. This is where I am currently stuck. I do some component level stuff, but I'm not sure where to look next on this issue.

    I have attached the schematic for the unit and the pages out of the manual relating to the Divide By N board. I'm hoping maybe someone can shed some light for me.

    Thanks!
     
  2. stevecast2024

    Thread Starter New Member

    Oct 8, 2016
    3
    0
    One correction... It is IC511 that pin 6 on the frequency comb runs down to, not IC512.
     
  3. stevecast2024

    Thread Starter New Member

    Oct 8, 2016
    3
    0
    Maybe these images will help also.
     
  4. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    What are the chip manufacturers numbers on Ic512, 511...
     
  5. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    Can we assume you have a signal generator to test the scanner?

    have you tried that pattern, abet the three connections for band assignment will be different, on another band to see if you get a similar condition?
     
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