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Re: [Sangean803] Re: FM Stereo

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  • Bill Pasternak
    Part of the trouble is due to adjacent stations running IBOC digital in addition to thair main analog carrier. The IBOC signal looks like strong white noise
    Message 1 of 3 , Oct 9, 2010
      Part of the trouble is due to adjacent stations running IBOC digital in addition to thair main analog carrier. The IBOC signal looks like strong "white noise" to the rafdio and its AFC circuit keeps hunting for "center carrier" as it was designed to do, but the IBOC sidebands make it almost impossible to find. So the radio keeps hunting for center carrier. (I have several AM/FM/SW sets that do this including a Grundig -- not just my Sangean set -- a R/S livry DX-440.) Its one of the side effects of IBOC here in the USA.


      2010-09-25



      Bill Pasternak



      发件人: broadw
      发送时间: 2010-09-23 21:43:47
      收件人: Sangean803
      抄送:
      主题: [Sangean803] Re: FM Stereo



      Hello Guido... I'm not a technician, but I have sometimes found this on my 803 as well. It might be a sign of age - the FM tuner can drift a bit over time.

      Try tuning up or down .5 MHz, and see if that holds the stereo signal.

      Any other ideas, guys?

      Matt
      --- In Sangean803@yahoogroups.com, "foxam2001" <foxam2001@...> wrote:
      >
      > I found what seems to be an intermittent problem. FM stations come in strong but when I switch to FM stereo the green indicator LED comes up briefly, you can hear the stereo sound also come up briefly in headphones and then it goes. It could be the switch but is working properly for wide-narrow am and I squirted some contact cleaner into it. Maybe someone in the group has gone through a similar experience.
      >
      > Best,
      >
      > Guido
      >





      [Non-text portions of this message have been removed]
    • Adam
      The Sangean 803 is frequency-synthesized. It does not contain an AFC circuit of any kind. IBOC carriers will not affect a properly-working 803 s tuning in
      Message 2 of 3 , Oct 12, 2010
        The Sangean 803 is frequency-synthesized. It does not contain an "AFC" circuit of any kind. IBOC carriers will not affect a properly-working 803's tuning in any way. It might affect listening, though (google k6sti's excellent FM-related pages).

        Interestingly the 803, amidst all this "hi tech" (well it was hi-tech when the 803 came out ;-) frequency-synthesis, it still contains a now-ancient good ol' fashioned ratio detector for FM, with the quintessential pink- and blue-cored coils. No fancy "quadrature" circuit even. (Not that a quad is all that fancy...)

        Back to the original problem, if it's intermittent -- the contact cleaner is a good idea but if that doesn't cure it then the next step is to open it up and have at it.

        Adam

        --- In Sangean803@yahoogroups.com, "Bill Pasternak" <arnewsline@...> wrote:
        >
        > Part of the trouble is due to adjacent stations running IBOC digital in addition to thair main analog carrier. The IBOC signal looks like strong "white noise" to the rafdio and its AFC circuit keeps hunting for "center carrier" as it was designed to do, but the IBOC sidebands make it almost impossible to find. So the radio keeps hunting for center carrier. (I have several AM/FM/SW sets that do this including a Grundig -- not just my Sangean set -- a R/S livry DX-440.) Its one of the side effects of IBOC here in the USA.
        >
        >
        > 2010-09-25
        >
        >
        >
        > Bill Pasternak
        >
        >
        >
        > å`件人: broadw
        > å`送时间: 2010-09-23 21:43:47
        > æ"¶ä»¶äººï¼š Sangean803
        > 抄送:
        > 主题: [Sangean803] Re: FM Stereo
        >
        >
        >
        > Hello Guido... I'm not a technician, but I have sometimes found this on my 803 as well. It might be a sign of age - the FM tuner can drift a bit over time.
        >
        > Try tuning up or down .5 MHz, and see if that holds the stereo signal.
        >
        > Any other ideas, guys?
        >
        > Matt
        > --- In Sangean803@yahoogroups.com, "foxam2001" <foxam2001@> wrote:
        > >
        > > I found what seems to be an intermittent problem. FM stations come in strong but when I switch to FM stereo the green indicator LED comes up briefly, you can hear the stereo sound also come up briefly in headphones and then it goes. It could be the switch but is working properly for wide-narrow am and I squirted some contact cleaner into it. Maybe someone in the group has gone through a similar experience.
        > >
        > > Best,
        > >
        > > Guido
        > >
        >
        >
        >
        >
        >
        > [Non-text portions of this message have been removed]
        >
      • Guido Santacana
        Contact cleaner did not work. It seems to be a sensitivity problem or a problem with the FM stereo circuit. I will try some realignment and see what happens. I
        Message 3 of 3 , Oct 14, 2010
          Contact cleaner did not work. It seems to be a sensitivity problem or a problem with the FM stereo circuit. I will try some realignment and see what happens. I am still looking for a junker set to get the rotary tuning encoder. There is also some display problems with numbers coming out incorrectly. The display was ok and the problems started a few days or a week after installing new batteries. All contacts are OK so it seems to be something different maybe having to do with the absence of the rotary encoder. Reception on AM, LW or SW is excellent.
           
          Best,
           
          Guido




          From: Adam <adenton@...>
          Subject: [Sangean803] Re: FM Stereo
          To: Sangean803@yahoogroups.com
          Date: Tuesday, October 12, 2010, 1:42 PM


           



          The Sangean 803 is frequency-synthesized. It does not contain an "AFC" circuit of any kind. IBOC carriers will not affect a properly-working 803's tuning in any way. It might affect listening, though (google k6sti's excellent FM-related pages).

          Interestingly the 803, amidst all this "hi tech" (well it was hi-tech when the 803 came out ;-) frequency-synthesis, it still contains a now-ancient good ol' fashioned ratio detector for FM, with the quintessential pink- and blue-cored coils. No fancy "quadrature" circuit even. (Not that a quad is all that fancy...)

          Back to the original problem, if it's intermittent -- the contact cleaner is a good idea but if that doesn't cure it then the next step is to open it up and have at it.

          Adam

          --- In Sangean803@yahoogroups.com, "Bill Pasternak" <arnewsline@...> wrote:
          >
          > Part of the trouble is due to adjacent stations running IBOC digital in addition to thair main analog carrier. The IBOC signal looks like strong "white noise" to the rafdio and its AFC circuit keeps hunting for "center carrier" as it was designed to do, but the IBOC sidebands make it almost impossible to find. So the radio keeps hunting for center carrier. (I have several AM/FM/SW sets that do this including a Grundig -- not just my Sangean set -- a R/S livry DX-440.) Its one of the side effects of IBOC here in the USA.
          >
          >
          > 2010-09-25
          >
          >
          >
          > Bill Pasternak
          >
          >
          >
          > å�`件人: broadw
          > å�`é€�时间: 2010-09-23 21:43:47
          > æ"¶ä»¶äººï¼š Sangean803
          > 抄�:
          > 主题: [Sangean803] Re: FM Stereo
          >
          >
          >
          > Hello Guido... I'm not a technician, but I have sometimes found this on my 803 as well. It might be a sign of age - the FM tuner can drift a bit over time.
          >
          > Try tuning up or down .5 MHz, and see if that holds the stereo signal.
          >
          > Any other ideas, guys?
          >
          > Matt
          > --- In Sangean803@yahoogroups.com, "foxam2001" <foxam2001@> wrote:
          > >
          > > I found what seems to be an intermittent problem. FM stations come in strong but when I switch to FM stereo the green indicator LED comes up briefly, you can hear the stereo sound also come up briefly in headphones and then it goes. It could be the switch but is working properly for wide-narrow am and I squirted some contact cleaner into it. Maybe someone in the group has gone through a similar experience.
          > >
          > > Best,
          > >
          > > Guido
          > >
          >
          >
          >
          >
          >
          > [Non-text portions of this message have been removed]
          >











          [Non-text portions of this message have been removed]
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