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Re: Wood -vs- steel base for homebrew shortwave set

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  • unclepennybags_2
    Gary, Thanks! That certainly answers my question. I actually have the same 6sn7 set. I built it on a wood chassis with a metal front panel. My experience
    Message 1 of 7 , Mar 1, 2008
      Gary,

      Thanks! That certainly answers my question. I actually have the
      same 6sn7 set. I built it on a wood chassis with a metal front
      panel.

      My experience with the tube got me thinking, but C.F. Rockey in his
      book about regens provides some schematics and when talking about
      some of them he recommends they be built in a metal cabinet. So, of
      course I always kind of wondered why.

      I have fun with regens generally and am hoping to build my best set
      yet for the upcoming Homebrewing Contest in July. I started scheming
      and tweaking early this year.....

      Regards,

      Unc

      --- In regenrx@yahoogroups.com, "wd4nka" <wd4nka@...> wrote:
      >
      > Yup. 6SN7 Twinplex.
      > First built it a'la 1950 ARRL manual,
      > then built it into a punched chassis /
      > Bud cabinet affair. Difference?
      >
      > Actually . . . i prefered the open wood
      > breadboard and metal front panel version.
      >
      > Signifigant difference? No. Certain things
      > were better with metal and certain things
      > were better on open breadboard. For the
      > life of me, i could never top the sheer
      > sensitivity on the 80m cw subband when it
      > came to that open breadboard. I have
      > pretty much met it, but not exceeded it. Big
      > advantage of the Bud cabinet and metal chassis
      > was the obvious shielding, but that is a double
      > edged sword. Ground problems were more
      > numerous with metal ( tie-point issues ) and
      > hum was more of a challenge than with open
      > wood. However, air currents affected the
      > open wood version . . . especially when in
      > the draft of the AC vent until i built a masonite
      > cabinet. Metal front panel did wonders for body-
      > hand capacity as regards the front panel dial
      > controls, but if you had to reach over the top
      > of the breadboard, as in my case an upper
      > shelf where the ACR was, you got a little drift.
      >
      > Nothing that couldn't be dealt with.
      >
      > But all in all, open wood breadboarding, provided
      > with a grounded front panel and insulated shaft
      > extensions - is an excellent construction venue.
      > Even with valve superhets i have stumbled upon
      > over the years!
      >
      > gary // wd4nka
      >
      >
      > ----- Original Message -----
      > From: unclepennybags_2
      > To: regenrx@yahoogroups.com
      > Sent: Friday, February 29, 2008 11:45 AM
      > Subject: [regenrx] Wood -vs- steel base for homebrew shortwave set
      >
      >
      > Has anyone ever built identical homebrew shortwave sets, except
      one is
      > on a steel chassis and the other with the components mounted on a
      > piece of wood? I'm wondering what the performance difference
      would
      > be. The reason that I'm asking is that I had an old vacuum tube
      > laying on my work bench next to my antenna lead-in while
      listening to
      > some SW this morning and I noticed that when I moved the tube
      away,
      > the tuning changed somewhat. I was surprised to see that it made
      a
      > difference.
      >
      > Regards,
      >
      > Unclepennybags
      >
      >
      >
      >
      >
      >
      > --------------------------------------------------------------------
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      >
    • deadgoose38
      Years ago, I built sets with a wooden breadboard base and tempered hardboard/Masonite panels. I had no end of problems with hand capacitance issues,
      Message 2 of 7 , Mar 18, 2008
        Years ago, I built sets with a wooden "breadboard" base and tempered
        hardboard/Masonite panels. I had no end of problems with hand
        capacitance issues, especially with regenerative designs. Using an
        aluminum panel took care of that. Later, I used an aluminum chassis a
        lot, but with a Masonite front panel. That seemed to have worked
        nicely, IIRC. Masonite is nice that in it takes paint well, and with
        "datak" letters, looks nice.

        I've seen some nice construction projects using the classic wood box.
        If you have access to a table saw, then that is even nicer, but some
        sort of metal shield or chassis seems to me to be obligatory.

        /paul

        W3FIS
      • John Berry.
        ... in the chassis,or in a front panel,that swamps out any hand capacity etc.Like building a P/c board circuit in a plastic case,thing runs wild,untill you
        Message 3 of 7 , Mar 19, 2008
          --- In regenrx@yahoogroups.com, "deadgoose38" <deadgoose@...> wrote:
          >
          > Years ago, I built sets with a wooden "breadboard" base and tempered
          > hardboard/Masonite panels. I had no end of problems with hand
          > capacitance issues, especially with regenerative designs. Using an
          > aluminum panel took care of that. Later, I used an aluminum chassis a
          > lot, but with a Masonite front panel. That seemed to have worked
          > nicely, IIRC. Masonite is nice that in it takes paint well, and with
          > "datak" letters, looks nice.
          >
          > I've seen some nice construction projects using the classic wood box.
          > If you have access to a table saw, then that is even nicer, but some
          > sort of metal shield or chassis seems to me to be obligatory.
          >
          > /paul
          >
          > W3FIS
          >
          >> HI PAUL.Interesting subject.I reckon it's the MASS of metal either
          in the chassis,or in a front panel,that swamps out any hand capacity
          etc.Like building a P/c board circuit in a plastic case,thing runs
          wild,untill you mount it on a alloy baseplate.John G1WOS.
        • Stephen Przepiora
          Now I have never done this for a receiver so it may not work, but I have used the foil tape used for ducting to shield the plastic cases that you get from
          Message 4 of 7 , Mar 19, 2008
            Now I have never done this for a receiver so it may not work, but I
            have used the foil tape used for ducting to shield the plastic cases
            that you get from Radio Shack and it does work.

            Of course on the inside it won't look "old". If anyone tries this
            before i get a chance, I would be interested in the results.

            Steve - KC2QXE

            On Wed, Mar 19, 2008 at 6:29 AM, John Berry. <jbbr35487@...> wrote:
            >
            >
            >
            >
            >
            >
            > --- In regenrx@yahoogroups.com, "deadgoose38" <deadgoose@...> wrote:
            > >
            > > Years ago, I built sets with a wooden "breadboard" base and tempered
            > > hardboard/Masonite panels. I had no end of problems with hand
            > > capacitance issues, especially with regenerative designs. Using an
            > > aluminum panel took care of that. Later, I used an aluminum chassis a
            > > lot, but with a Masonite front panel. That seemed to have worked
            > > nicely, IIRC. Masonite is nice that in it takes paint well, and with
            > > "datak" letters, looks nice.
            > >
            > > I've seen some nice construction projects using the classic wood box.
            > > If you have access to a table saw, then that is even nicer, but some
            > > sort of metal shield or chassis seems to me to be obligatory.
            > >
            > > /paul
            > >
            > > W3FIS
            > >
            > >> HI PAUL.Interesting subject.I reckon it's the MASS of metal either
            > in the chassis,or in a front panel,that swamps out any hand capacity
            > etc.Like building a P/c board circuit in a plastic case,thing runs
            > wild,untill you mount it on a alloy baseplate.John G1WOS.
            >
            >
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