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Help identifying this old AM transmitter

Discussion in '"Boat Anchor" & Classic Equipment' started by W7UUU, Feb 11, 2019.

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  1. KJ6ZOL

    KJ6ZOL Ham Member QRZ Page

    It reminds me of those 1940s Warner Bros cartoons where Bugs Bunny would grab something electrical and thus make a complete circuit, then he would go rigid and light up in a changing array of colors for a few seconds. Of course, Bugs lived. I suspect that a person in the real world who grabbed a plate tuning knob with 4500vdc on it would be more like that old 1990s radio commercial, I can't remember what it was selling, where a guy gets electrified and his buddy says "Frank, you're giving off sparks! Frank?..."
  2. KA1BSZ

    KA1BSZ Ham Member QRZ Page

    Thought I saw this same rig in one of the ARRl hand books back in the 60's?
  3. N2EY

    N2EY Premium Subscriber QRZ Page

    Nope. It's a unique design. The exciter part is from the 1940s-early 5os.
  4. SM0AOM

    SM0AOM Ham Member QRZ Page

    KB3OUK has correctly identified the exciter in the rig with the RCA logo as the W1TS design, which later became the Millen 90800.


    Regarding the poor battered HRO, if the octal tubes are original, it could be a late-war HRO-5, which were produced in large quantities for lend-lease and extensively used in the British forces.

    It also looks that it has the die-cast metal gear drive housing which is common for the pre-war and post-war HRO:s, but not for the later war-time production which used a pressed-sheet metal housing.

    The receiver could then be a re-tubed pre-war HRO, or have been assembled from bits and pieces from several receivers.

    "Radio archaeology" at its best...

    KD2ACO and N2EY like this.
  5. W9AAM

    W9AAM Ham Member QRZ Page

    Some "Appliance Operator" / "Old Timer Wannabe" will get his ass cooked trying to get it going again.

    This needs to be parted out and put together by someone that knows what he is doing before someone gets killed.

    In the car show word, the term "Rat Rod" comes to mind.

  6. KA1BSZ

    KA1BSZ Ham Member QRZ Page

    I know I've seen it in a picture in some publication.It was many years ago,I just can't recall where it was.
  7. N2EY

    N2EY Premium Subscriber QRZ Page

    As @SM0AOM points out, it's a design originated by W1TS, Don Mix, in QST for November, 1940, which became the Millen 90800.
  8. KA1BSZ

    KA1BSZ Ham Member QRZ Page

    yep....I knew it!....I knew I saw it somewhere.
    N2EY likes this.
  9. KM1H

    KM1H Ham Member QRZ Page

    The military demanded National dump the big glass HRO tubes late in the war and use octals, all metal except for the 6V6, which Millen had fought against for years. The tube in the photo looks like a 6F6G or one of the other variants such as the 6G6G and 6W6G, it doesnt appear tall enough for a 6L6G.....but.
    The miniature tubes shown were in the same location as used in the HRO-50 and National converted many octal tube sets for customers at far less cost than a new 50. Ive learned to never call a National mod a hammy hambone hack without looking closely at the work as their huge ham based employee staff from R&D to machine and paint shop encouraged that work. The crystal filter was never used in the RAS or other 175 kc IF variants.

    That miniature tube sticking up from the crystal filter is pure homebrew but for what??

    The coil shown is strictly 7-14 mc General Coverage only, no bandspread as was the W version, and may be modified for 20M bandspread which was quite simple. The trimmer cap peeking over the first RF amp would support that as an antenna trimmer.
    National also modified many E coils for 160.

    Id say that radio started as a HRO-W which were everywhere after the war at low cost, even still in a crate with all coils and PS.

    K2XT likes this.

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