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Re: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test

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  • Alan
    ... Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test ... I find it takes so long to work out where A, B, C, is in relation to the big scheme of
    Message 1 of 13 , Jan 10, 2013
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      ----- Original Message -----
      Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test


      >
      > From Robby's original build notes: "Enabling PTT also should pull the base of Q3 down, turning it on and generating the S12V
      > supply to the PA on transmit.
      >
      > Bob, G8VOI, has provided a nice little trouble-shooting schematic to aid for those who may experience problems with this stage.
      > http://www.wb5rvz.com/sdr/ensemble/05_rf_bob_g8voi.htm"
      >

      I find it takes so long to work out where A, B, C, is in relation to the big scheme of things!

      What is the base voltage of Q3?
      The collector is definitely wrong.
      Some have put the wrong transistor in Q3 position.
      As Warren says compare with Bob's readings.

      73 Alan G4ZFQ
    • R. R. (Robby) Robson
      Alan See http://wb5rvz.org/ensemble_rxtx/10_pa#pastandingcurrentandforwardbias ... -- Cheers, Robby Richard R. (Robby) Robson LTC USA (RET) www.wb5rvz.com
      Message 2 of 13 , Jan 11, 2013
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        Alan

        See http://wb5rvz.org/ensemble_rxtx/10_pa#pastandingcurrentandforwardbias
        On Fri, Jan 11, 2013 at 12:48 AM, Alan <alan4alan@...> wrote:
         


        ----- Original Message -----
        Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test

        >
        > From Robby's original build notes: "Enabling PTT also should pull the base of Q3 down, turning it on and generating the S12V
        > supply to the PA on transmit.
        >
        > Bob, G8VOI, has provided a nice little trouble-shooting schematic to aid for those who may experience problems with this stage.
        > http://www.wb5rvz.com/sdr/ensemble/05_rf_bob_g8voi.htm"
        >

        I find it takes so long to work out where A, B, C, is in relation to the big scheme of things!

        What is the base voltage of Q3?
        The collector is definitely wrong.
        Some have put the wrong transistor in Q3 position.
        As Warren says compare with Bob's readings.

        73 Alan G4ZFQ





        --
        Cheers,
        Robby
         
        Richard R. (Robby) Robson
        LTC USA (RET)
      • Alan
        ... Subject: Re: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test ... Robby. Funny, first time I clicked on that link it took me to the Home page for the
        Message 3 of 13 , Jan 11, 2013
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          ----- Original Message -----
          Subject: Re: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test


          >See http://wb5rvz.org/ensemble_rxtx/10_pa#pastandingcurrentandforwardbias

          Robby.

          Funny, first time I clicked on that link it took me to the Home page for the RXTX!
          Second time to the exact place.

          But when we find the place on which the query is based we still have to relate A, B... to the whole schematic.
          A bad voltage can be caused by something remote from the measuring point.

          I don't suppose there is an answer, even if the query is accompanied by a link (this very rarely happens) it can take longer to work
          out exactly where the reading is made than to work out why it might be wrong.

          Perhaps a full schematic, up to the point of build, customised for each particular page with A, B... inserted. Seems like a lot of
          work for you? But it could be educational as well if the constructor looks to see what he is actually doing in the grand scale of
          things.

          73 Alan G4ZFQ



          >
          > ----- Original Message -----
          > Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test
          >
          > >
          > > From Robby's original build notes: "Enabling PTT also should pull the
          > base of Q3 down, turning it on and generating the S12V
          > > supply to the PA on transmit.
          > >
          > > Bob, G8VOI, has provided a nice little trouble-shooting schematic to aid
          > for those who may experience problems with this stage.
          > > http://www.wb5rvz.com/sdr/ensemble/05_rf_bob_g8voi.htm"
          > >
          >
          > I find it takes so long to work out where A, B, C, is in relation to the
          > big scheme of things!
          >
          > What is the base voltage of Q3?
          > The collector is definitely wrong.
          > Some have put the wrong transistor in Q3 position.
          > As Warren says compare with Bob's readings.
          >
        • R. R. (Robby) Robson
          Alan: Good idea, but it may be a little problematic given the size and scope of the RXTX s schematic. I may give it a try - but no promises. One approach may
          Message 4 of 13 , Jan 11, 2013
          Alan:

          Good idea, but it may be a little problematic given the size and scope of the RXTX's schematic.  I may give it a try - but no promises.  One approach may be to take the entire schematic and copy it once per stage, with a link to the stage's version of the total schematic embedded at strategic points on the page for the stage.  I could then use colored masks to dim the past (yellow) and future (blue) parts and leave the current stage's parts undimmed.  See attached example.

          Do you think that would be helpful.

          On Fri, Jan 11, 2013 at 10:37 AM, Alan <alan4alan@...> wrote:
           


          ----- Original Message -----
          Subject: Re: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test

          >See http://wb5rvz.org/ensemble_rxtx/10_pa#pastandingcurrentandforwardbias

          Robby.

          Funny, first time I clicked on that link it took me to the Home page for the RXTX!
          Second time to the exact place.

          But when we find the place on which the query is based we still have to relate A, B... to the whole schematic.
          A bad voltage can be caused by something remote from the measuring point.

          I don't suppose there is an answer, even if the query is accompanied by a link (this very rarely happens) it can take longer to work
          out exactly where the reading is made than to work out why it might be wrong.

          Perhaps a full schematic, up to the point of build, customised for each particular page with A, B... inserted. Seems like a lot of
          work for you? But it could be educational as well if the constructor looks to see what he is actually doing in the grand scale of
          things.

          73 Alan G4ZFQ



          >
          > ----- Original Message -----
          > Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test
          >
          > >
          > > From Robby's original build notes: "Enabling PTT also should pull the
          > base of Q3 down, turning it on and generating the S12V
          > > supply to the PA on transmit.
          > >
          > > Bob, G8VOI, has provided a nice little trouble-shooting schematic to aid
          > for those who may experience problems with this stage.
          > > http://www.wb5rvz.com/sdr/ensemble/05_rf_bob_g8voi.htm"
          > >
          >
          > I find it takes so long to work out where A, B, C, is in relation to the
          > big scheme of things!
          >
          > What is the base voltage of Q3?
          > The collector is definitely wrong.
          > Some have put the wrong transistor in Q3 position.
          > As Warren says compare with Bob's readings.
          >




          --
          Cheers,
          Robby
           
          Richard R. (Robby) Robson
          LTC USA (RET)
        • R. R. (Robby) Robson
          Alan: The image is a little better on the website (go to the Ensemble RXTX kit s RF/IO stage page and check out the Progressive Schematic hearing at the
          Message 5 of 13 , Jan 11, 2013
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            Alan:
            The image is a little better on the website (go to the Ensemble RXTX kit's RF/IO stage page and check out the "Progressive Schematic" hearing at the beginning if the testing section of that stage.

            On Fri, Jan 11, 2013 at 4:09 PM, R. R. (Robby) Robson <rrrobson@...> wrote:
             
            [Attachment(s) from R. R. (Robby) Robson included below]

            Alan:


            Good idea, but it may be a little problematic given the size and scope of the RXTX's schematic.  I may give it a try - but no promises.  One approach may be to take the entire schematic and copy it once per stage, with a link to the stage's version of the total schematic embedded at strategic points on the page for the stage.  I could then use colored masks to dim the past (yellow) and future (blue) parts and leave the current stage's parts undimmed.  See attached example.

            Do you think that would be helpful.

            On Fri, Jan 11, 2013 at 10:37 AM, Alan <alan4alan@...> wrote:
             


            ----- Original Message -----
            Subject: Re: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test

            >See http://wb5rvz.org/ensemble_rxtx/10_pa#pastandingcurrentandforwardbias

            Robby.

            Funny, first time I clicked on that link it took me to the Home page for the RXTX!
            Second time to the exact place.

            But when we find the place on which the query is based we still have to relate A, B... to the whole schematic.
            A bad voltage can be caused by something remote from the measuring point.

            I don't suppose there is an answer, even if the query is accompanied by a link (this very rarely happens) it can take longer to work
            out exactly where the reading is made than to work out why it might be wrong.

            Perhaps a full schematic, up to the point of build, customised for each particular page with A, B... inserted. Seems like a lot of
            work for you? But it could be educational as well if the constructor looks to see what he is actually doing in the grand scale of
            things.

            73 Alan G4ZFQ



            >
            > ----- Original Message -----
            > Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test
            >
            > >
            > > From Robby's original build notes: "Enabling PTT also should pull the
            > base of Q3 down, turning it on and generating the S12V
            > > supply to the PA on transmit.
            > >
            > > Bob, G8VOI, has provided a nice little trouble-shooting schematic to aid
            > for those who may experience problems with this stage.
            > > http://www.wb5rvz.com/sdr/ensemble/05_rf_bob_g8voi.htm"
            > >
            >
            > I find it takes so long to work out where A, B, C, is in relation to the
            > big scheme of things!
            >
            > What is the base voltage of Q3?
            > The collector is definitely wrong.
            > Some have put the wrong transistor in Q3 position.
            > As Warren says compare with Bob's readings.
            >




            --
            Cheers,
            Robby
             
            Richard R. (Robby) Robson
            LTC USA (RET)




            --
            Cheers,
            Robby
             
            Richard R. (Robby) Robson
            LTC USA (RET)
          • jerryburg
            Alan, Thanks for the link to the schematic. Verified Q3 as 2N3906. Did various tests of voltage with following results. Q3 Base RX was 3.18vdc and in TX
            Message 6 of 13 , Jan 11, 2013
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              Alan,

              Thanks for the link to the schematic.

              Verified Q3 as 2N3906. Did various tests of voltage with following results.

              Q3 Base RX was 3.18vdc and in TX 3.14vdc.

              At U1, Ovdc all Pins in RX and TX mode.

              At U4, Pins 1-3, 0vdc in RX and TX. Pin 4 2.69vdc in RX and 47mvdc in TX.

              R50/R51 was 2.19vdc in RX and 39mvdc in TX.

              73 Jerry N5GKJ

              --- In softrock40@yahoogroups.com, "R. R. (Robby) Robson" wrote:
              >
              > Alan
              >
              > See http://wb5rvz.org/ensemble_rxtx/10_pa#pastandingcurrentandforwardbias
              > On Fri, Jan 11, 2013 at 12:48 AM, Alan wrote:
              >
              > > **
              > >
              > >
              > >
              > > ----- Original Message -----
              > > Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test
              > >
              > > >
              > > > From Robby's original build notes: "Enabling PTT also should pull the
              > > base of Q3 down, turning it on and generating the S12V
              > > > supply to the PA on transmit.
              > > >
              > > > Bob, G8VOI, has provided a nice little trouble-shooting schematic to aid
              > > for those who may experience problems with this stage.
              > > > http://www.wb5rvz.com/sdr/ensemble/05_rf_bob_g8voi.htm"
              > > >
              > >
              > > I find it takes so long to work out where A, B, C, is in relation to the
              > > big scheme of things!
              > >
              > > What is the base voltage of Q3?
              > > The collector is definitely wrong.
              > > Some have put the wrong transistor in Q3 position.
              > > As Warren says compare with Bob's readings.
              > >
              > > 73 Alan G4ZFQ
              > >
              > >
              > >
              > >
              >
              >
              >
              > --
              > Cheers,
              > Robby
              >
              > Richard R. (Robby) Robson
              > LTC USA (RET)
              > www.wb5rvz.com
              > www.wb5rvz.org
              > www.rafino.org
              >
            • warrenallgyer
              Jerry I am going to jump in here in case you are in a hurry and Alan may be busy. The base voltage at Q3 is incorrect. It should be your PS voltage minus about
              Message 7 of 13 , Jan 11, 2013
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                Jerry

                I am going to jump in here in case you are in a hurry and Alan may be busy.

                The base voltage at Q3 is incorrect. It should be your PS voltage minus about 0.7 volts...if you are using a 12V PS then it should be 11.3.

                I would guess Q3 is either bad or installed incorrectly.

                You do not appear to be getting the proper S12V signal. You can look at the hairpin of R37. It should be 0V during receive and near to the PS voltage on transmit. Without S12V at 12V during transmit the rig will not go into transmit mode.

                Warren Allgyer - W8TOD

                --- In softrock40@yahoogroups.com, "jerryburg" wrote:
                >
                >
                >
                > Alan,
                >
                > Thanks for the link to the schematic.
                >
                > Verified Q3 as 2N3906. Did various tests of voltage with following results.
                >
                > Q3 Base RX was 3.18vdc and in TX 3.14vdc.
                >
                > At U1, Ovdc all Pins in RX and TX mode.
                >
                > At U4, Pins 1-3, 0vdc in RX and TX. Pin 4 2.69vdc in RX and 47mvdc in TX.
                >
                > R50/R51 was 2.19vdc in RX and 39mvdc in TX.
                >
                > 73 Jerry N5GKJ
                >
                > --- In softrock40@yahoogroups.com, "R. R. (Robby) Robson" wrote:
                > >
                > > Alan
                > >
                > > See http://wb5rvz.org/ensemble_rxtx/10_pa#pastandingcurrentandforwardbias
                > > On Fri, Jan 11, 2013 at 12:48 AM, Alan wrote:
                > >
                > > > **
                > > >
                > > >
                > > >
                > > > ----- Original Message -----
                > > > Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test
                > > >
                > > > >
                > > > > From Robby's original build notes: "Enabling PTT also should pull the
                > > > base of Q3 down, turning it on and generating the S12V
                > > > > supply to the PA on transmit.
                > > > >
                > > > > Bob, G8VOI, has provided a nice little trouble-shooting schematic to aid
                > > > for those who may experience problems with this stage.
                > > > > http://www.wb5rvz.com/sdr/ensemble/05_rf_bob_g8voi.htm"
                > > > >
                > > >
                > > > I find it takes so long to work out where A, B, C, is in relation to the
                > > > big scheme of things!
                > > >
                > > > What is the base voltage of Q3?
                > > > The collector is definitely wrong.
                > > > Some have put the wrong transistor in Q3 position.
                > > > As Warren says compare with Bob's readings.
                > > >
                > > > 73 Alan G4ZFQ
                > > >
                > > >
                > > >
                > > >
                > >
                > >
                > >
                > > --
                > > Cheers,
                > > Robby
                > >
                > > Richard R. (Robby) Robson
                > > LTC USA (RET)
                > > www.wb5rvz.com
                > > www.wb5rvz.org
                > > www.rafino.org
                > >
                >
              • Alan
                ... Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test ... Yes Q3 base voltage is impossible if Q3 is good and installed properly. In a hurry, been
                Message 8 of 13 , Jan 12, 2013
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                  ----- Original Message -----
                  Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test


                  > I am going to jump in here in case you are in a hurry and Alan may be busy.
                  >
                  > The base voltage at Q3 is incorrect. It should be your PS voltage minus about 0.7 volts...if you are using a 12V PS then it should
                  > be 11.3.
                  >
                  > I would guess Q3 is either bad or installed incorrectly.
                  >

                  Yes Q3 base voltage is impossible if Q3 is good and installed properly.

                  In a hurry, been playing WSPR 50mW on 60m and USA spots.
                  But G4ZFQ 5.288634 +0 0 IO90ir +17 0.050 KB9AMG EN52tx 6287 3907

                  Really musy be impossible! But it's in the database....

                  73 Alan G4ZFQ



                  > You do not appear to be getting the proper S12V signal. You can look at the hairpin of R37. It should be 0V during receive and
                  > near to the PS voltage on transmit. Without S12V at 12V during transmit the rig will not go into transmit mode.
                  >
                  > Warren Allgyer - W8TOD
                  >
                  > --- In softrock40@yahoogroups.com, "jerryburg" wrote:
                  >>
                  >>
                  >>
                  >> Alan,
                  >>
                  >> Thanks for the link to the schematic.
                  >>
                  >> Verified Q3 as 2N3906. Did various tests of voltage with following results.
                  >>
                  >> Q3 Base RX was 3.18vdc and in TX 3.14vdc.
                  >>
                  >> At U1, Ovdc all Pins in RX and TX mode.
                  >>
                  >> At U4, Pins 1-3, 0vdc in RX and TX. Pin 4 2.69vdc in RX and 47mvdc in TX.
                  >>
                  >> R50/R51 was 2.19vdc in RX and 39mvdc in TX.
                  >>
                  >> 73 Jerry N5GKJ
                  >>
                  >> --- In softrock40@yahoogroups.com, "R. R. (Robby) Robson" wrote:
                  >> >
                  >> > Alan
                  >> >
                  >> > See http://wb5rvz.org/ensemble_rxtx/10_pa#pastandingcurrentandforwardbias
                  >> > On Fri, Jan 11, 2013 at 12:48 AM, Alan wrote:
                  >> >
                  >> > > **
                  >> > >
                  >> > >
                  >> > >
                  >> > > ----- Original Message -----
                  >> > > Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test
                  >> > >
                  >> > > >
                  >> > > > From Robby's original build notes: "Enabling PTT also should pull the
                  >> > > base of Q3 down, turning it on and generating the S12V
                  >> > > > supply to the PA on transmit.
                  >> > > >
                  >> > > > Bob, G8VOI, has provided a nice little trouble-shooting schematic to aid
                  >> > > for those who may experience problems with this stage.
                  >> > > > http://www.wb5rvz.com/sdr/ensemble/05_rf_bob_g8voi.htm"
                  >> > > >
                  >> > >
                  >> > > I find it takes so long to work out where A, B, C, is in relation to the
                  >> > > big scheme of things!
                  >> > >
                  >> > > What is the base voltage of Q3?
                  >> > > The collector is definitely wrong.
                  >> > > Some have put the wrong transistor in Q3 position.
                  >> > > As Warren says compare with Bob's readings.
                  >> > >
                  >> > > 73 Alan G4ZFQ
                  >> > >
                  >> > >
                  >> > >
                  >> > >
                  >> >
                  >> >
                  >> >
                  >> > --
                  >> > Cheers,
                  >> > Robby
                  >> >
                  >> > Richard R. (Robby) Robson
                  >> > LTC USA (RET)
                  >> > www.wb5rvz.com
                  >> > www.wb5rvz.org
                  >> > www.rafino.org
                  >> >
                  >>
                  >
                  >
                  >
                  >
                  > ------------------------------------
                  >
                  > Yahoo! Groups Links
                  >
                  >
                  >
                • Alan
                  ... Subject: Re: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test ... RF/IO stage page and check out the Progressive Schematic hearing at the beginning
                  Message 9 of 13 , Jan 13, 2013
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                    ----- Original Message -----
                    Subject: Re: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test


                    >The image is a little better on the website (go to the Ensemble RXTX kit's
                    RF/IO stage page and check out the "Progressive Schematic" hearing at the
                    beginning if the testing section of that stage.

                    Robby,

                    I still do not see anything on that page.

                    But the attachment in your previous post is the sort of thing I was thinking about.

                    73 Alan G4ZFQ



                    On Fri, Jan 11, 2013 at 4:09 PM, R. R. (Robby) Robson <rrrobson@...>wrote:

                    > **
                    >
                    > [Attachment(s) <#13c2ba940932e32b_TopText> from R. R. (Robby) Robson
                    > included below]
                    >
                    > Alan:
                    >
                    > Good idea, but it may be a little problematic given the size and scope of
                    > the RXTX's schematic. I may give it a try - but no promises. One approach
                    > may be to take the entire schematic and copy it once per stage, with a link
                    > to the stage's version of the total schematic embedded at strategic points
                    > on the page for the stage. I could then use colored masks to dim the past
                    > (yellow) and future (blue) parts and leave the current stage's parts
                    > undimmed. See attached example.
                    >
                  • R. R. (Robby) Robson
                    Alan: Oops, my bad. I tested the process on my development machine and never uploaded it to the site. Try the Ensemble RXTX RF/IO stage again (nestled
                    Message 10 of 13 , Jan 13, 2013
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                      Alan:

                      Oops, my bad.  I tested the process on my development machine and never uploaded it to the site.  Try the Ensemble RXTX RF/IO stage again (nestled between the completed photos and the test sections.

                      On Sun, Jan 13, 2013 at 2:18 AM, Alan <alan4alan@...> wrote:
                       


                      ----- Original Message -----
                      Subject: Re: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test

                      >The image is a little better on the website (go to the Ensemble RXTX kit's
                      RF/IO stage page and check out the "Progressive Schematic" hearing at the
                      beginning if the testing section of that stage.

                      Robby,

                      I still do not see anything on that page.

                      But the attachment in your previous post is the sort of thing I was thinking about.

                      73 Alan G4ZFQ


                      On Fri, Jan 11, 2013 at 4:09 PM, R. R. (Robby) Robson rrrobson@...>wrote:

                      > **
                      >
                      > [Attachment(s) <#13c2ba940932e32b_TopText> from R. R. (Robby) Robson

                      > included below]
                      >
                      > Alan:
                      >
                      > Good idea, but it may be a little problematic given the size and scope of
                      > the RXTX's schematic. I may give it a try - but no promises. One approach
                      > may be to take the entire schematic and copy it once per stage, with a link
                      > to the stage's version of the total schematic embedded at strategic points
                      > on the page for the stage. I could then use colored masks to dim the past
                      > (yellow) and future (blue) parts and leave the current stage's parts
                      > undimmed. See attached example.
                      >




                      --
                      Cheers,
                      Robby
                       
                      Richard R. (Robby) Robson
                      LTC USA (RET)
                    • jerryburg
                      Ordered up a new Q3(2N3906). Cannot find electronic parts locally and had to cool my heels for a week waiting for it to arrive. Replaced Q3 and everything is
                      Message 11 of 13 , Jan 21, 2013
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                        Ordered up a new Q3(2N3906). Cannot find electronic parts locally and had to cool my heels for a week waiting for it to arrive.

                        Replaced Q3 and everything is working fine at this time.

                        Thanks for pointing me in the right direction. This is my first Softrock.

                        About to start on my Delta 44 Interface Module and working toward getting on the air.

                        73

                        Jerry N5GKJ

                        --- In softrock40@yahoogroups.com, "Alan" wrote:
                        >
                        >
                        > ----- Original Message -----
                        > Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test
                        >
                        >
                        > > I am going to jump in here in case you are in a hurry and Alan may be busy.
                        > >
                        > > The base voltage at Q3 is incorrect. It should be your PS voltage minus about 0.7 volts...if you are using a 12V PS then it should
                        > > be 11.3.
                        > >
                        > > I would guess Q3 is either bad or installed incorrectly.
                        > >
                        >
                        > Yes Q3 base voltage is impossible if Q3 is good and installed properly.
                        >
                        > In a hurry, been playing WSPR 50mW on 60m and USA spots.
                        > But G4ZFQ 5.288634 +0 0 IO90ir +17 0.050 KB9AMG EN52tx 6287 3907
                        >
                        > Really musy be impossible! But it's in the database....
                        >
                        > 73 Alan G4ZFQ
                        >
                        >
                        >
                        > > You do not appear to be getting the proper S12V signal. You can look at the hairpin of R37. It should be 0V during receive and
                        > > near to the PS voltage on transmit. Without S12V at 12V during transmit the rig will not go into transmit mode.
                        > >
                        > > Warren Allgyer - W8TOD
                        > >
                        > > --- In softrock40@yahoogroups.com, "jerryburg" wrote:
                        > >>
                        > >>
                        > >>
                        > >> Alan,
                        > >>
                        > >> Thanks for the link to the schematic.
                        > >>
                        > >> Verified Q3 as 2N3906. Did various tests of voltage with following results.
                        > >>
                        > >> Q3 Base RX was 3.18vdc and in TX 3.14vdc.
                        > >>
                        > >> At U1, Ovdc all Pins in RX and TX mode.
                        > >>
                        > >> At U4, Pins 1-3, 0vdc in RX and TX. Pin 4 2.69vdc in RX and 47mvdc in TX.
                        > >>
                        > >> R50/R51 was 2.19vdc in RX and 39mvdc in TX.
                        > >>
                        > >> 73 Jerry N5GKJ
                        > >>
                        > >> --- In softrock40@yahoogroups.com, "R. R. (Robby) Robson" wrote:
                        > >> >
                        > >> > Alan
                        > >> >
                        > >> > See http://wb5rvz.org/ensemble_rxtx/10_pa#pastandingcurrentandforwardbias
                        > >> > On Fri, Jan 11, 2013 at 12:48 AM, Alan wrote:
                        > >> >
                        > >> > > **
                        > >> > >
                        > >> > >
                        > >> > >
                        > >> > > ----- Original Message -----
                        > >> > > Subject: [softrock40] Re: Ensemble RXTX Failed Driver/PA Test
                        > >> > >
                        > >> > > >
                        > >> > > > From Robby's original build notes: "Enabling PTT also should pull the
                        > >> > > base of Q3 down, turning it on and generating the S12V
                        > >> > > > supply to the PA on transmit.
                        > >> > > >
                        > >> > > > Bob, G8VOI, has provided a nice little trouble-shooting schematic to aid
                        > >> > > for those who may experience problems with this stage.
                        > >> > > > http://www.wb5rvz.com/sdr/ensemble/05_rf_bob_g8voi.htm"
                        > >> > > >
                        > >> > >
                        > >> > > I find it takes so long to work out where A, B, C, is in relation to the
                        > >> > > big scheme of things!
                        > >> > >
                        > >> > > What is the base voltage of Q3?
                        > >> > > The collector is definitely wrong.
                        > >> > > Some have put the wrong transistor in Q3 position.
                        > >> > > As Warren says compare with Bob's readings.
                        > >> > >
                        > >> > > 73 Alan G4ZFQ
                        > >> > >
                        > >> > >
                        > >> > >
                        > >> > >
                        > >> >
                        > >> >
                        > >> >
                        > >> > --
                        > >> > Cheers,
                        > >> > Robby
                        > >> >
                        > >> > Richard R. (Robby) Robson
                        > >> > LTC USA (RET)
                        > >> > www.wb5rvz.com
                        > >> > www.wb5rvz.org
                        > >> > www.rafino.org
                        > >> >
                        > >>
                        > >
                        > >
                        > >
                        > >
                        > > ------------------------------------
                        > >
                        > > Yahoo! Groups Links
                        > >
                        > >
                        > >
                        >
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