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Preferences in Regeneration controls.

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  • wd4nka@aol.com
    In a message dated 6/1/2005 2:17:19 AM Eastern Daylight Time, ... ****** An age old question. No firm answer. A lot depends on the builder. Lots of folks
    Message 1 of 2 , Jun 1, 2005
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      In a message dated 6/1/2005 2:17:19 AM Eastern Daylight Time,
      zoran.tukovic1@zg.t-com.hr writes:


      > Which is the better, Hartley-type or Armstrong-type.
      > Which one have lower de-tuning effect, better stability and smoother
      > regeneration ?
      >
      > Regards,
      > Tuky
      >

      ****** An age old question. No firm answer. A lot depends on the builder.
      Lots of folks like the tapped hartley tetrode or pentode with a screen grid
      throttle. The other end of the spectrum (me) prefers a gassy low mu triode
      armstrong with adjustable tickler with a plate pot for regen control. As a
      rule,
      i never operate a regen on it's native frequency higher than 40m, preferably
      around 3-4 mc. I'll use a twin tube xtal converter for higher bands, as the
      Regenerodyne ( my pet regen rx circuit ) uses. My normal shift at 3 mc is
      about +/- 1kc at full rotation of the plate pot at that frequency. I have
      never,
      repeat, never had a noise problem with any of my milsurp 25 to 50k control
      pots in over 30 years of building. Threshold transition at 3.5 megs has
      always
      been smooth and covers about 20 degrees of pot rotation, which is quite
      considerable for a threshold spread. Naturally this changes as frequency
      increases. At 7.3mc, threshold is much shorter, deviation is about doubled.
      Not intolerable, but not near as silky as 160 or 80m.

      But honestly, opinions vary far and wide.

      For an excellent resource, check out the Aug. 1929 QST research article
      concerning this very issue. The ARRL staff tested every known regen
      configuration commonly employed up to that time, and rated each one
      as per regen control freq deviation, noise in the regen control, sensitivity,
      susceptibility to block, volume, etc. One interesting thing to note in this
      article: they describe the "evolution" of regeneration control, starting with
      varying the inductance by physical methods, then progressed to capacitive
      feedback control via throttle, and finally the last morph: pot control of
      plate
      voltage. This was quite a surprise to me, i always thought the throttle cap
      was the latest and greatest. Not so by 1929 standards using a triode,
      apparently. They note that varying the C of the feedback circuit, while
      noiseless, introduced intolerable frequency deviation. That was my
      experience as well. Anyway, it's a great read, and a handy resource.

      gary // wd4nka

      Visit my site at: <A HREF="http://www.qsl.net/wd4nka/">http://www.qsl.net/wd4nka/</A>


      [Non-text portions of this message have been removed]
    • Zoran Tukovic
      Thanx very much, Tuky ... From: To: Sent: Thursday, June 02, 2005 3:19 AM Subject: [regenrx] Preferences in
      Message 2 of 2 , Jun 2, 2005
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        Thanx very much,

        Tuky


        ----- Original Message -----
        From: <wd4nka@...>
        To: <regenrx@yahoogroups.com>
        Sent: Thursday, June 02, 2005 3:19 AM
        Subject: [regenrx] Preferences in Regeneration controls.


        > In a message dated 6/1/2005 2:17:19 AM Eastern Daylight Time,
        > zoran.tukovic1@zg.t-com.hr writes:
        >
        >
        >> Which is the better, Hartley-type or Armstrong-type.
        >> Which one have lower de-tuning effect, better stability and smoother
        >> regeneration ?
        >>
        >> Regards,
        >> Tuky
        >>
        >
        > ****** An age old question. No firm answer. A lot depends on the
        > builder.
        > Lots of folks like the tapped hartley tetrode or pentode with a screen
        > grid
        > throttle. The other end of the spectrum (me) prefers a gassy low mu
        > triode
        > armstrong with adjustable tickler with a plate pot for regen control. As
        > a
        > rule,
        > i never operate a regen on it's native frequency higher than 40m,
        > preferably
        > around 3-4 mc. I'll use a twin tube xtal converter for higher bands, as
        > the
        > Regenerodyne ( my pet regen rx circuit ) uses. My normal shift at 3 mc is
        > about +/- 1kc at full rotation of the plate pot at that frequency. I have
        > never,
        > repeat, never had a noise problem with any of my milsurp 25 to 50k control
        > pots in over 30 years of building. Threshold transition at 3.5 megs has
        > always
        > been smooth and covers about 20 degrees of pot rotation, which is quite
        > considerable for a threshold spread. Naturally this changes as frequency
        > increases. At 7.3mc, threshold is much shorter, deviation is about
        > doubled.
        > Not intolerable, but not near as silky as 160 or 80m.
        >
        > But honestly, opinions vary far and wide.
        >
        > For an excellent resource, check out the Aug. 1929 QST research article
        > concerning this very issue. The ARRL staff tested every known regen
        > configuration commonly employed up to that time, and rated each one
        > as per regen control freq deviation, noise in the regen control,
        > sensitivity,
        > susceptibility to block, volume, etc. One interesting thing to note in
        > this
        > article: they describe the "evolution" of regeneration control, starting
        > with
        > varying the inductance by physical methods, then progressed to capacitive
        > feedback control via throttle, and finally the last morph: pot control of
        > plate
        > voltage. This was quite a surprise to me, i always thought the throttle
        > cap
        > was the latest and greatest. Not so by 1929 standards using a triode,
        > apparently. They note that varying the C of the feedback circuit, while
        > noiseless, introduced intolerable frequency deviation. That was my
        > experience as well. Anyway, it's a great read, and a handy resource.
        >
        > gary // wd4nka
        >
        > Visit my site at: <A
        > HREF="http://www.qsl.net/wd4nka/">http://www.qsl.net/wd4nka/</A>
        >
        >
        > [Non-text portions of this message have been removed]
        >
        >
        >
        > "In the interest of Regenerating radio's lost art of Regeneration"
        > Yahoo! Groups Links
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
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