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Re: Soft keying on TR-4

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  • minosberrymin
    Thanks for your suggestion, Garey. Yes, I ve checked the bias as per your description a couple weeks ago and find it is right on the mark and solid as I key. I
    Message 1 of 7 , May 1, 2012
      Thanks for your suggestion, Garey. Yes, I've checked the bias as per your description a couple weeks ago and find it is right on the mark and solid as I key. I concede my 6JB6s are problematic; they are the ones that came with the rig and 140 watts is all I can squeeze from them. For a long time 85 watts was all I could get out of them. My attention is now directed earlier in the system, perhaps to the 9 MHz oscillator, V2 (phase shift oscillator in CW transmit)and/or= maybe the V4 transmit mixer. Any thoughts are always most appreciated.
    • Garey Barrell
      OK. Check R40, and the Screen and Cathode resistors of the PA. The Carrier Oscillator doesn t vary much. V2 is used ONLY to generate the SIDETONE in the TR-4
      Message 2 of 7 , May 1, 2012
        OK. Check R40, and the Screen and Cathode resistors of the PA.

        The Carrier Oscillator doesn't vary much. V2 is used ONLY to generate the SIDETONE in the TR-4 and
        has nothing to do with the RF chain. A weak transmit mixer tube or misalignment is possible, and of
        course a weak Driver (or R40).

        If the output power drops off as you go up in frequency, it may just be soft PA tubes. A new set is
        the only real test here.

        Have you tried 40M?

        73, Garey - K4OAH
        Glen Allen, VA

        Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
        and TR-4/C Service Supplement CDs
        <www.k4oah.com>


        minosberrymin wrote:
        > Thanks for your suggestion, Garey. Yes, I've checked the bias as per your description a couple weeks ago and find it is right on the mark and solid as I key. I concede my 6JB6s are problematic; they are the ones that came with the rig and 140 watts is all I can squeeze from them. For a long time 85 watts was all I could get out of them. My attention is now directed earlier in the system, perhaps to the 9 MHz oscillator, V2 (phase shift oscillator in CW transmit)and/or= maybe the V4 transmit mixer. Any thoughts are always most appreciated.
        >
      • minosberrymin
        Thanks...like always...Garey. Those are some juicy things to check into tonight. Yes, that V2 thing really had me scratching my head. The way Drake wrote it in
        Message 3 of 7 , May 1, 2012
          Thanks...like always...Garey. Those are some juicy things to check into tonight. Yes, that V2 thing really had me scratching my head. The way Drake wrote it in the manual made it sound like it had a transmit function although I couldn't see it. But then again, I've only been licensed 43 years so I've still got my "learner's permit" the way I see it. I checked 40 meters and it too sounded "soft" almost a chirp. Woke up in the middle of the night last night...the thought came to me that I have a click filter in line all the time and maybe it was distorting the keying...so I came downstairs and fired it up, but no such luck that that was it. So I'll be checking R40, cathode resistors, screen, mixer and driver and will report back. Thanks a lot for the help to help me get this orphan working again.
        • Garey Barrell
          Well I just passed 55 years, and I m still learning. That s half the fun! I just took another look at the TR-4, and it dawned on me that only V3, V4 and V6
          Message 4 of 7 , May 1, 2012
            Well I just passed 55 years, and I'm still learning. That's half the fun!

            I just took another look at the TR-4, and it dawned on me that only V3, V4 and V6 are actually
            'keyed' for CW. They're grid-block keyed, via R18, R19, and R119 plus C31. I would suggest
            swapping out V3 first, as it is actually the oscillator. If you don't have another 6EA8 you could
            swap with V1 just to check. If no help, return them to their original sockets.

            I wasn't quite truthful the other day about V2. It DOES only generate the SIDETONE, but that same
            signal is used to activate the VOX on CW as well. But it would have no effect on your keying situation.

            I just realized I don't have your name or call??

            73, Garey - K4OAH
            Glen Allen, VA

            Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
            and TR-4/C Service Supplement CDs
            <www.k4oah.com>


            minosberrymin wrote:
            > Thanks...like always...Garey. Those are some juicy things to check into tonight. Yes, that V2 thing really had me scratching my head. The way Drake wrote it in the manual made it sound like it had a transmit function although I couldn't see it. But then again, I've only been licensed 43 years so I've still got my "learner's permit" the way I see it. I checked 40 meters and it too sounded "soft" almost a chirp. Woke up in the middle of the night last night...the thought came to me that I have a click filter in line all the time and maybe it was distorting the keying...so I came downstairs and fired it up, but no such luck that that was it. So I'll be checking R40, cathode resistors, screen, mixer and driver and will report back. Thanks a lot for the help to help me get this orphan working again.
            >
            >
            >
            > ------------------------------------
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            > Yahoo! Groups Links
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            >
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          • Richard Knoppow
            ... From: Garey Barrell To: Sent: Tuesday, May 01, 2012 2:51 PM Subject: Re: [DrakeRadio] Re: Soft keying
            Message 5 of 7 , May 1, 2012
              ----- Original Message -----
              From: "Garey Barrell" <k4oah@...>
              To: <DrakeRadio@yahoogroups.com>
              Sent: Tuesday, May 01, 2012 2:51 PM
              Subject: Re: [DrakeRadio] Re: Soft keying on TR-4


              > Well I just passed 55 years, and I'm still learning.
              > That's half the fun!
              >
              > I just took another look at the TR-4, and it dawned on me
              > that only V3, V4 and V6 are actually
              > 'keyed' for CW. They're grid-block keyed, via R18, R19,
              > and R119 plus C31. I would suggest
              > swapping out V3 first, as it is actually the oscillator.
              > If you don't have another 6EA8 you could
              > swap with V1 just to check. If no help, return them to
              > their original sockets.
              >
              > I wasn't quite truthful the other day about V2. It DOES
              > only generate the SIDETONE, but that same
              > signal is used to activate the VOX on CW as well. But it
              > would have no effect on your keying situation.
              >
              > I just realized I don't have your name or call??
              >
              > 73, Garey - K4OAH
              > Glen Allen, VA

              I wonder if there is anywhere where the keying signal
              could be examined. I mean the DC used for grid blocking.
              It might be useful to see what sort of rise and fall times
              it has. If normal it would at least eliminate some things.


              --
              Richard Knoppow
              Los Angeles
              WB6KBL
              dickburk@...
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