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Re: [regenrx] Re: Dual 6SN7 Project

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  • wd4nka
    Hey, Joe: Congratulations on your success so far. Visited your site, boy, nice images! (nice schematics, too! : ) I have not used TubePad with Paint Shop, i
    Message 1 of 16 , Dec 1, 2006
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      Hey, Joe:

      Congratulations on your success so far. Visited your site, boy, nice images!
      (nice schematics, too! :>)

      I have not used TubePad with Paint Shop, i pretty much designed it for the toolbox
      that comes with Microsoft Paint, but it looks like it's working with PSP.

      Wonder how the RF amp is handling the large, out of passband signals? GG amps
      are pretty bullet-proof, but it would seem that it would amplify out of bandpass signals
      as well as those in the detector's own tuning range. **If** you get a lot of pulling from a
      signal, say, 30kc up or down, see if tuning the cathode input may help. (tap the coil
      down for lower impedance for GG amp cathode matching.)

      Nice looking layout!

      gary // wd4nka


      ----- Original Message -----
      From: wj5mh@...
      To: regenrx@yahoogroups.com
      Sent: Friday, December 01, 2006 12:18 AM
      Subject: [regenrx] Re: Dual 6SN7 Project


      It's working, but I had a major issue with the main tuning cap. I spent
      hours trying to stop the plates from shorting at different places in the
      rotation. Talk about frustrated. I ended using a different cap, but it's slightly
      off center to the front shaft, so more work needs to be done. (May I suggest
      that you use caps with wider plate spacing's.)

      I found the cap problem while wiring the radio. I had the cap for a few
      years, so decided to check it before soldering. Good thing.

      But, the radio is playing nicely, and I've been listing to 40 for about an
      hour. The web site schematic has been updated, and includes my coil
      information which I changed because of the replacement variable cap.

      The radio is far from done. I need to go through it and check all the
      voltages. The audio doesn't sound distorted, but I'll check with a scope. It
      will drive a speaker, but not a well as I would like. Both the high and low Z
      phones work great. I need to change to low Z jack to
      stereo. Thought I had one in the junk box.

      So far I am pleasantly surprised!

      73,
      Joe


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






      [Non-text portions of this message have been removed]
    • Larry Beaty
      Congratulations are in order, Joe! Get the waitress, order some Champaign! ... From: wj5mh@aol.com To:
      Message 2 of 16 , Dec 1, 2006
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        Congratulations are in order, Joe! Get the waitress, order some Champaign!

        ----- Original Message -----
        From: wj5mh@...<mailto:wj5mh@...>
        To: regenrx@yahoogroups.com<mailto:regenrx@yahoogroups.com>
        Sent: Friday, December 01, 2006 12:18 AM
        Subject: [regenrx] Re: Dual 6SN7 Project


        It's working, but I had a major issue with the main tuning cap. I spent
        hours trying to stop the plates from shorting at different places in the
        rotation. Talk about frustrated. I ended using a different cap, but it's slightly
        off center to the front shaft, so more work needs to be done. (May I suggest
        that you use caps with wider plate spacing's.)

        I found the cap problem while wiring the radio. I had the cap for a few
        years, so decided to check it before soldering. Good thing.

        But, the radio is playing nicely, and I've been listing to 40 for about an
        hour. The web site schematic has been updated, and includes my coil
        information which I changed because of the replacement variable cap.

        The radio is far from done. I need to go through it and check all the
        voltages. The audio doesn't sound distorted, but I'll check with a scope. It
        will drive a speaker, but not a well as I would like. Both the high and low Z
        phones work great. I need to change to low Z jack to
        stereo. Thought I had one in the junk box.

        So far I am pleasantly surprised!

        73,
        Joe


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





        [Non-text portions of this message have been removed]
      • exwb6lxa
        --Hi Joe. Congrats! Those little frail broadcast type varibles can be a real chore to straighten when they get dinged, or curious people touch them to hard.
        Message 3 of 16 , Dec 1, 2006
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          --Hi Joe. Congrats! Those little frail broadcast type varibles can
          be a real chore to straighten when they get dinged, or curious
          people touch them to hard. It is a real dieing art to make them not
          short. I have seen brushs that the old radio men used to fix them.
          They had many tiny, very stiff wires that could carefully be
          inserted into the field of plates and run through them to straighten
          slightly bent ones. It can be done, but a real chore. The heavier
          plated versions also are more stable for temperature changes as well
          as more mechanically sturdy. They say the heavy brass plated ones
          are the best for stability. I lost the bookmark of the website that
          previews the rcvr. I too am interested how the first stage works.
          Triodes are not known for having a lot of audio output in these sets
          that dont use a very strong triode like a 45, or 10, etc drawing a
          lot of power and their voltage gains are not real high usually.
          Their distortions are usually quite low though. If headphone
          operation is what is mainly wanted they are great. If real booming
          loud speaker operation is what you are looking for maybe you still
          have room for a 6V6, 6K6, 6AQ5, etc later. Hope your new cap doesnt
          make you have to change things too much. Thanks again for keeping
          use up on all the great news and info. 73's, Doug, KM6OR.Joe.- In
          regenrx@yahoogroups.com, wj5mh@... wrote:
          >
          > It's working, but I had a major issue with the main tuning cap.
          I spent
          > hours trying to stop the plates from shorting at different places
          in the
          > rotation. Talk about frustrated. I ended using a different cap,
          but it's slightly
          > off center to the front shaft, so more work needs to be done.
          (May I suggest
          > that you use caps with wider plate spacing's.)
          >
          > I found the cap problem while wiring the radio. I had the cap for
          a few
          > years, so decided to check it before soldering. Good thing.
          >
          > But, the radio is playing nicely, and I've been listing to 40 for
          about an
          > hour. The web site schematic has been updated, and includes my
          coil
          > information which I changed because of the replacement variable
          cap.
          >
          > The radio is far from done. I need to go through it and check all
          the
          > voltages. The audio doesn't sound distorted, but I'll check with
          a scope. It
          > will drive a speaker, but not a well as I would like. Both the
          high and low Z
          > phones work great. I need to change to low Z jack to
          > stereo. Thought I had one in the junk box.
          >
          > So far I am pleasantly surprised!
          >
          > 73,
          > Joe
          >
          >
          >
          > [Non-text portions of this message have been removed]
          >
        • wj5mh@aol.com
          TubePad seems to work great with PSP. I need to work with it more to get a good feel for it... I ve been using PSP for years, now. The RF amp isn t causing
          Message 4 of 16 , Dec 1, 2006
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            TubePad seems to work great with PSP. I need to work with it more to get a good feel for it... I've been using PSP for years, now.

            The RF amp isn't causing any issues that I can tell. I had plenty of signals on the bench with a 10' wire, and when I connected it to an 88' zepp, I had to turn down the gain, but I didn't notice any pulling on 40 even with the high power broadcasters. I will be looking at the amp to see just how much amplification is actually happening.

            Also, running to the gain control isn't shunting the RF to ground through the pot's shell. I quickly parallelled 5K across the pot and the gain did not increase.

            My power supply DC is a bit higher than expected using the isolation transformer. I figured I'd pull more current than I am thus reducing the voltage. I wanted to see if using one of these transformers would work.

            I see Fry Electronics had a 200 watt isolation transformer for $18 last week. (I'm not using one of them.)

            The higher voltage (and probably more turns on the tickler) caused the regen pot to be ineffective. I had to drop the value on the low side of the control to 5.6k from 10kto get enough headroom so the regen could be adjusted.

            I do need to look at the signal path, and maybe I can get to that today. I also need to check voltages at various points, too.

            Great fun.
            ________________________________________________________________________
            Check out the new AOL. Most comprehensive set of free safety and security tools, free access to millions of high-quality videos from across the web, free AOL Mail and more.


            [Non-text portions of this message have been removed]
          • wj5mh@aol.com
            http://members.aol.com/wpe8eum/oldregen.html Yup, I ll stick with the headphones with 6SN7 s. I ve got room to change both the main and bandspread caps and may
            Message 5 of 16 , Dec 1, 2006
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              http://members.aol.com/wpe8eum/oldregen.html

              Yup, I'll stick with the headphones with 6SN7's.

              I've got room to change both the main and bandspread caps and may do that later.


              -----Original Message-----
              From: km6or@...
              To: regenrx@yahoogroups.com
              Sent: Fri, 1 Dec 2006 11:22 AM
              Subject: [regenrx] Re: Dual 6SN7 Project


              ...Triodes are not known for having a lot of audio output in these sets
              that dont use a very strong triode like a 45, or 10, etc drawing a
              lot of power and their voltage gains are not real high usually.
              Their distortions are usually quite low though. If headphone
              operation is what is mainly wanted they are great. If real booming
              loud speaker operation is what you are looking for maybe you still
              have room for a 6V6, 6K6, 6AQ5, etc later. Hope your new cap doesnt
              make you have to change things too much. Thanks again for keeping
              use up on all the great news and info. 73's, Doug, KM6OR.Joe.
              ________________________________________________________________________
              Check out the new AOL. Most comprehensive set of free safety and security tools, free access to millions of high-quality videos from across the web, free AOL Mail and more.


              [Non-text portions of this message have been removed]
            • wj5mh@aol.com
              The dual regen project is done...for now. My wife had a garage sale today, so I got to play. The web site has been updated if you re interested. The
              Message 6 of 16 , Dec 2, 2006
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                The dual regen project is done...for now. My wife had a garage sale today,
                so I got to play. The web site has been updated if you're interested. The
                schematic now includes changes and voltage readings. Thanks for everyone's
                assistance.

                _http://members.aol.com/wpe8eum/oldregen.html_
                (http://members.aol.com/wpe8eum/oldregen.html)

                73,
                Joe (WJ5MH)


                [Non-text portions of this message have been removed]
              • exwb6lxa
                -Hi Joe. That rcvr looks great. Sounds like you learned a lot on the project too, that is great! The detector s do pull in or try to lock on signals and
                Message 7 of 16 , Dec 3, 2006
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                  -Hi Joe. That rcvr looks great. Sounds like you learned a lot on
                  the project too, that is great! The detector's do "pull in" or try
                  to lock on signals and that is why it is hard to reproduce low freq
                  beat notes on cw with a regen detecter. The closer you get in freq
                  (low pitchs) the more likely they are to try to pull in and lock. By
                  reducing the signal level getting to the detecter with the gain
                  control in the first amp you can help this. This can make them
                  distort the tone also as it is trying to lock, then it unlocks and
                  makes for a gravelly sounding beat note on CW. Many of the old
                  timers could tell you this and just got used to listening to their
                  CW beat notes at a little higher pitch. The farther away you get,
                  the more signal it takes from the station to make this happen. The
                  voltages you display on the scematic look right in line with what
                  the tube books tell us is correct. The cathode bias resisters are
                  doing their jobs well. I was wondering if a shunt resister in the
                  cathode of the 1st stage across the pot would work well, looks like
                  it did. Well done!, beautifull job. Many of us could learn from
                  your example by getting in there and building, using and displaying
                  them. 73's, Doug, KM6OR.-- In regenrx@yahoogroups.com, wj5mh@...
                  wrote:
                  >
                  > The dual regen project is done...for now. My wife had a garage
                  sale today,
                  > so I got to play. The web site has been updated if you're
                  interested. The
                  > schematic now includes changes and voltage readings. Thanks for
                  everyone's
                  > assistance.
                  >
                  > _http://members.aol.com/wpe8eum/oldregen.html_
                  > (http://members.aol.com/wpe8eum/oldregen.html)
                  >
                  > 73,
                  > Joe (WJ5MH)
                  >
                  >
                  > [Non-text portions of this message have been removed]
                  >
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