TS-940SAT is deaf above 13.999 MHz

Discussion in 'General Technical Questions and Answers' started by N2ZDH, Jan 15, 2020.

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  1. WA1UIL

    WA1UIL Premium Subscriber QRZ Page

    Awesome step by step logical troubleshooting operation with a good result. Still curious what ate up the board seemingly only in one spot, strange.
    A great job all around.
     
    N2ZDH likes this.
  2. PD7P

    PD7P Ham Member QRZ Page

    After struggling with my 940 I came across this thread...Think it will help me as my 940 is deaf above 4 mhz...nice winterproject..
     
  3. PD7P

    PD7P Ham Member QRZ Page

    Edit....in further view/thinking.....I only have receiving signal between 2.5 and 4 mHz.So the problem could also be on the LPF board...Anyone some suggestions as to where to go from here??
     
  4. N8YX

    N8YX Ham Member QRZ Page

    Have a signal generator?

    Bypass the LPF Unit by injecting a carrier into the stage after it. Do this for each band the radio covers.

    See signals? If yes, think LPF or control logic associated with it. If no, PLL unlock problems.
     
  5. PD7P

    PD7P Ham Member QRZ Page

    I took a closer look at the solder side of the pll board.....cold solder point inspection so to call.
    Some owner before me had done that as well...and connected two points.
    Touch-up and checked the entire print for further f**kups..several cold points resoldered.
    Put it back together and I am a happy operator!!
     
    N2ZDH, K7TRF and KA0HCP like this.
  6. KI4FQZ

    KI4FQZ Ham Member QRZ Page

    Well done OM!!....Isn't this a great hobby??!!
     
  7. PD7P

    PD7P Ham Member QRZ Page

    It sure is...next project....the power supply upgrade/replacement
     
  8. N8YX

    N8YX Ham Member QRZ Page

    Did this to a '930 I own. Have the kit for a '940 which is in the repair queue - going over the whole rig top to bottom.

    Highly recommend it. The radio loses a significant amount of weight. TX power and RX operation is unchanged from stock. There's enough room for additional output filtering capacitors in the PSU fan area if desired, though I haven't had to add anything in the way of such.
     
  9. PD7P

    PD7P Ham Member QRZ Page

    I know,have done the conversion on my 930 about 12 years ago.....
    I was the one that posted the article on Eham about the conversion on which the original developer (PA2VC ) reacted with a posting.
    After that several other hams posted articles as follow up of that conversion.
    At this moment I already have the Quint power supply on my desk,coming week I will start the work on the 940.
    The 930 on which i did the conversion is still in my shack and is still going strong.
     
    N2ZDH and WD5GWY like this.

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