Tuesday, April 9, 2013


     Photos will have to follow later, but I have made two little "patch plates" to cover non-original holes in the chassis and allow reinstallation of the original-style RF output connectors (ceramic feedthroughs), power cord grommet, and a new fuseholder.

     Over the weekend, I installed a new (used) desk in my ham shack.  I brought it home in pieces and reassembled in the basement, without instructions.  Also an old, heavy-duty, three-shelf printer stand, from back when printers were good-sized items.  I'll use t for radio gear.

     Last but not least, I found the power supply I built several years ago for another transmitter project and never tested.  It's an example of late-1930s breadboard construction and yes, there will be pictures, especially if it works.  (Huge long-term project, which I return to from time to time.)

     Readers of this blog may enjoy J. D. Leach's Thermionic Emissions website.  He's something of an expert on the Clough-Brengle line of test equipment, first-rate in its day and still pretty good.*  Many items from his collection were on display at the most recent Indiana Historical Radio Society meeting.
* We must, of course, make an exception for audio test oscillators, which were not really tamed until Hewlett and Packard put the Wein-bridge oscillator to work in '39, just in time for Walt DisneyClough-Brengle, starting several years earlier, used the beat-frequency technique to generate audio sinewaves just like everyone else at the time, and the resulting output tended be rather, ahem, richer and more full than a pure sine wave.  But so was the output of everyone else's, and C-B's no-nonsense approach to user interface made their audio oscillator simple to use.


  1. I've got one of the HP "200" series of audio oscillators. It's one of the later ones in a more 'vertical' cabinet, but it's basically the same circuit.

    Took a while to rebuild it, mostly mechanical and capacitor replacement, but it works 100%, and is really clean.

  2. HP 200CD series... Good is good. Usually easy to keep working well.
    Both a classic instrument and a valuable addition to any bench today.

    their RF instruments were nothing to sneeze at.. think 600 series and the 8040.


  3. I like h/p for most things -- even scopes for X-Y apps. Their scopes never really triggered as well as the classic Teks.