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Re: [VLF_Group] Query re: Renato's E202 rcvr schematic

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  • john nelson
    The BC237A crosses to an NTE 123AP (The other # doesn t cross to anything and may be the typo).  Any low noise silicon NPN should work in that configuration.
    Message 1 of 4 , May 2, 2013
      The BC237A crosses to an NTE 123AP (The other # doesn't cross to anything and may be the typo).  Any low noise silicon NPN should work in that configuration.



      ________________________________
      From: thb201 <hudakjm@...>
      To: VLF_Group@yahoogroups.com
      Sent: Thursday, May 2, 2013 3:16 PM
      Subject: [VLF_Group] Query re: Renato's E202 rcvr schematic



       
      On Renato's web page for this receiver the schematic shows two transistors. One is marked BC237A and the other is BC23 A (a space between the "3" and the "A"). Can I assume that the second one is a typo and that the space should have a "7" in there? In other words both transistors are BC237A's?

      http://www.vlf.it/romero2/explorer-e202.html

      Further, as these transistors appear to be obsolete and no longer available according to Mouser's web site, is there a 2Nxxxx equivalent, perhaps our old friend the 2N3904?

      Thanks in advance.

      Cheers,
      John




      [Non-text portions of this message have been removed]
    • renato
      An updated version of E202 scheme is on line: http://www.vlf.it/romero2/explorer-e202.html The high pass filter has been moved in the front-end stage: in this
      Message 2 of 4 , May 3, 2013
        An updated version of E202 scheme is on line:
        http://www.vlf.it/romero2/explorer-e202.html

        The high pass filter has been moved in the front-end stage:
        in this way the receiver works also with strong hum noise without saturating.


        Renato



        --- In VLF_Group@yahoogroups.com, john nelson <jnelson123_us@...> wrote:
        >
        > The BC237A crosses to an NTE 123AP (The other # doesn't cross to anything and may be the typo).  Any low noise silicon NPN should work in that configuration.
        >
        >
        >
        > ________________________________
        > From: thb201 <hudakjm@...>
        > To: VLF_Group@yahoogroups.com
        > Sent: Thursday, May 2, 2013 3:16 PM
        > Subject: [VLF_Group] Query re: Renato's E202 rcvr schematic
        >
        >
        >
        >  
        > On Renato's web page for this receiver the schematic shows two transistors. One is marked BC237A and the other is BC23 A (a space between the "3" and the "A"). Can I assume that the second one is a typo and that the space should have a "7" in there? In other words both transistors are BC237A's?
        >
        > http://www.vlf.it/romero2/explorer-e202.html
        >
        > Further, as these transistors appear to be obsolete and no longer available according to Mouser's web site, is there a 2Nxxxx equivalent, perhaps our old friend the 2N3904?
        >
        > Thanks in advance.
        >
        > Cheers,
        > John
        >
        >
        >
        >
        > [Non-text portions of this message have been removed]
        >
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