Question about TS-430s and additional PCB installed.

Discussion in 'General Technical Questions and Answers' started by N0CTL, Apr 25, 2019.

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  1. N0CTL

    N0CTL Platinum Subscriber Platinum Subscriber QRZ Page

    I have this problem. I see an old Kenwood radio and I have to have it. Maybe some of you can sympathize? I picked up my latest radio, a reasonably clean TS-430s, which has been tested and I know it works with rated output on all bands.

    Naturally, I do my usual assessment and cleanup of any newly acquired radios and determine which mods, if any. that may have been performed, and look for any other obvious issues. Its a fairly complete radio, including the FM board, and all the filters, with the exception of the AM filter. When I got to the bottom side of the radio to look at the RF unit PCB, however, I noticed this small, 1"x2" PCB installed between the front panel and the RF unit PCB


    [​IMG]IMG_0507

    [​IMG]IMG_0500

    This board make its connections to the control-unit at D36, and on pin 14 of IC13 (VCC I assume), and as well as pin 5 (EQL) of CN16

    [​IMG]IMG_0505

    I'm not familiar with this board and I'm wondering if others might have some idea as to its purpose.

    -John
     
  2. N0CTL

    N0CTL Platinum Subscriber Platinum Subscriber QRZ Page

    And yes, in that first image, there are two wires next to this mystery module that have been clipped. A purple wire and a gray wire. I haven't traced them yet to see where they go.
     
  3. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    The National IC CD4027 is a Dual JK flip-flop. Obsolete but still available.
     
  4. N0CTL

    N0CTL Platinum Subscriber Platinum Subscriber QRZ Page

    Those clipped wires go to connector 10, which seems to be used with the mod to open up the out-of-band transmissions from 1.6-30 MHz. In the pic below, I have the connector 10 plug removed to get a better look at things. Rather than remove the plug, it seems the previous owner just cut the wires from pins 2-TX1 and 3-WRX. I'll revert this mod

    [​IMG]IMG_0508 by John Scherer, on Flickr
     
  5. N0CTL

    N0CTL Platinum Subscriber Platinum Subscriber QRZ Page

    Yeah. I got that one. It seems that whoever produced these boards sanded the labels off the other two chips, which leads me to believe that this was a commercial product.
     
  6. KD8DEY

    KD8DEY Ham Member QRZ Page

    At least it's not a Roger Beep...
    Ymmv
     
    N0CTL and K7MH like this.
  7. K7TRF

    K7TRF Premium Subscriber QRZ Page

    Does one wire run to the VFO? IOW, could it be some form of VFO stabilizer like a huff n puff or X-Lock with that flip flop serving as a reference frequency divider? That tall cylinder near the flip flop looks like it could be a crystal serving as the timebase reference.
     
    WR2E likes this.
  8. WR2E

    WR2E Ham Member QRZ Page

    At first I thought maybe tone encoder... for 10M FM... doesn't seem to be in the audio line though, does it?
     
  9. VE7DQ

    VE7DQ Ham Member QRZ Page

    Could this board be a speed reducer for the VFO tuning? One of my Kenwoods (probably the TS-440) has such a device, but it was homebrewed point-to-point wiring.

    I doubt that it would be a huffnpuff; it would be totally unnecessary in a synthesized TS-430.
     
  10. WG8Z

    WG8Z Ham Member QRZ Page

    I'm going with the huff and puff.
     

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