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Tapping into 10.8MHz IF with v9 switched bandpass?

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  • David Kopf
    Hi all, I ve been unable to get the SRv9 with the switched bandpass daughterboard to see the IF signal from my old Tandy PRO35 scanner (same as Uniden Bearcat
    Message 1 of 3 , Jan 1, 2010
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      Hi all,

      I've been unable to get the SRv9 with the switched bandpass daughterboard
      to see the IF signal from my old Tandy PRO35 scanner (same as Uniden Bearcat
      BC100). I can scope the 20 millivolt 10.8MHz signal on pin 20 of the
      TK10421M and would have thought it would show something obvious on the
      spectrum as I tune the v9 through that frequency, but I see absolutely
      nothing. I'm connecting to the input transformer through a capacitor, with
      the antenna return grounded to the Tandy case. The v9 seems to be working
      well enough around that frequency (get WWV, 40 meter USB traffic), so I am
      wondering if the switched bandpass filter is not suitable for tapping this
      IF, maybe has way too low impedence?

      As I understand it the SR6.2 with a 40 meter bandpass has been used for
      this, but it has a different front end (LC filter on the input instead of
      coupling directly to a transformer). Do I need the similar 40 meter
      daughterboard for the SRv9?
    • David Kopf
      I finally got a pretty good signal with three turns of wire around the IF card and tuning the SRv9 to 10.849 Mhz. Pics show WinradHD with the PRO35 scanner set
      Message 2 of 3 , Jan 3, 2010
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        I finally got a pretty good signal with three turns of wire around the IF
        card and tuning the SRv9 to 10.849 Mhz. Pics show WinradHD with the PRO35
        scanner set to a National Weather Service FM station at 162.550 MHz.
        http://groups.yahoo.com/group/softrock40/photos/album/1354230897/pic/list

        Suggestions for improving the pickup coil would be welcomed :)

        ----- Original Message -----
        From: "David Kopf" <dak664@...>
        To: <softrock40@yahoogroups.com>
        Sent: Friday, January 01, 2010 6:25 PM
        Subject: [softrock40] Tapping into 10.8MHz IF with v9 switched bandpass?


        > Hi all,
        >
        > I've been unable to get the SRv9 with the switched bandpass daughterboard
        > to see the IF signal from my old Tandy PRO35 scanner (same as Uniden
        > Bearcat
        > BC100). I can scope the 20 millivolt 10.8MHz signal on pin 20 of the
        > TK10421M and would have thought it would show something obvious on the
        > spectrum as I tune the v9 through that frequency, but I see absolutely
        > nothing. I'm connecting to the input transformer through a capacitor,
        > with
        > the antenna return grounded to the Tandy case. The v9 seems to be working
        > well enough around that frequency (get WWV, 40 meter USB traffic), so I am
        > wondering if the switched bandpass filter is not suitable for tapping this
        > IF, maybe has way too low impedence?
        >
        > As I understand it the SR6.2 with a 40 meter bandpass has been used for
        > this, but it has a different front end (LC filter on the input instead of
        > coupling directly to a transformer). Do I need the similar 40 meter
        > daughterboard for the SRv9?
        >
        >
      • pond.james_pond
        Hello to everyone in the group. Having ordered an SRv9+EBP kit I d intended to experiment with a PCR-1000 (10.7MHz IF tap with a 0.1uf capacitor) along similar
        Message 3 of 3 , Jan 3, 2010
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          Hello to everyone in the group.
          Having ordered an SRv9+EBP kit I'd intended to experiment with a PCR-1000 (10.7MHz IF tap with a 0.1uf capacitor) along similar lines as yourself for 6/2M. I'd assumed it would be necessary to bypass the BPF to get results? I can only suggest you keep experimanting.

          --- In softrock40@yahoogroups.com, "David Kopf" <dak664@...> wrote:
          >
          > I finally got a pretty good signal with three turns of wire around the IF
          > card and tuning the SRv9 to 10.849 Mhz. Pics show WinradHD with the PRO35
          > scanner set to a National Weather Service FM station at 162.550 MHz.
          > http://groups.yahoo.com/group/softrock40/photos/album/1354230897/pic/list
          >
          > Suggestions for improving the pickup coil would be welcomed :)
          >
          > ----- Original Message -----
          > From: "David Kopf" <dak664@...>
          > To: <softrock40@yahoogroups.com>
          > Sent: Friday, January 01, 2010 6:25 PM
          > Subject: [softrock40] Tapping into 10.8MHz IF with v9 switched bandpass?
          >
          >
          > > Hi all,
          > >
          > > I've been unable to get the SRv9 with the switched bandpass daughterboard
          > > to see the IF signal from my old Tandy PRO35 scanner (same as Uniden
          > > Bearcat
          > > BC100). I can scope the 20 millivolt 10.8MHz signal on pin 20 of the
          > > TK10421M and would have thought it would show something obvious on the
          > > spectrum as I tune the v9 through that frequency, but I see absolutely
          > > nothing. I'm connecting to the input transformer through a capacitor,
          > > with
          > > the antenna return grounded to the Tandy case. The v9 seems to be working
          > > well enough around that frequency (get WWV, 40 meter USB traffic), so I am
          > > wondering if the switched bandpass filter is not suitable for tapping this
          > > IF, maybe has way too low impedence?
          > >
          > > As I understand it the SR6.2 with a 40 meter bandpass has been used for
          > > this, but it has a different front end (LC filter on the input instead of
          > > coupling directly to a transformer). Do I need the similar 40 meter
          > > daughterboard for the SRv9?
          > >
          > >
          >
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