Tuesday, July 23, 2013


     E.F. Johnson built a wide range of amateur radio transmitters (among other things), starting in the 1920s.  They hit their stride with the postwar ham radio boom and continued through the early days of SSB.  Every last one of the postwar rigs was a "Viking" something-or-other, which I suppose isn't a huge surprise for a company based in Waseca MN, up there where the descendants of Vikings farmed the land.  The first two, delightful behemoths, were the Viking I and Viking II, but after that, there were Adventurers, Rangers, Navigators, Invaders(!) and the Challenger:
     There was one on a table at the Indy Hamfest, priced over $100 (a bit high, I thought) but the guy was starting to pack up and when he noticed my interest, suggested the price was highly negotiable.  I named a rather low one and he was okay with it -- even added a microphone.

     It's a CW/AM rig, the latter provided by screen-modulating a couple of TV sweep tubes (6DQ6) with a miniature beam tetrode audio tube (6AQ5).  One does not expect high fidelity from this kind of arrangement but given a decent load, it should be adequate.

     The knobs for bandswitch, "excitation" (grid drive) and mode switch are notably missing pointers to tell you where they're set.  The originals were sort of subtle, white plastic pieces glued in at the bottom of the knobs, and I'll have to work out a replacement.

     Does it work?  The seller claimed it did -- it's got Johnson's poorly-documented "push to talk" modification (no schematic, just a step-by-step and partial pictorial) and a connections-unknown mic socket, so I'll want to trace all that out first, clean it up and then, perhaps, power it up via The Gadget. 

     What's The Gadget?  That's a post for another time!


  1. I want to attend a hamfest with you. You are a better shopper than I am.

  2. Electric Radio magazine had a full rebuild of one a few issues back.

    To replace the missing pointers, I've seen Q-Tip sticks used, along with small, white plastic rod from places like Grainger or McMaster's.

  3. I can't say I know what half of this stuff does, ma'am, but I'm glad you're out there recording the existence of it all.
    Keep up the good work!

  4. That's neat how the Viking Challenger logo mimics the meter. Symmetrical front panel layouts might not be very ergonomic, but they sure look nice.

  5. teeritz: Oh, don't worry, most of it is pretty simple.

    Dave: It is nice-looking. Johnson was very much into symmetry. Sadly, I'm told that's an iron-vane meter and overshoots wildly. All part of the charm, I suppose.

  6. at that price i might be willing to put it away in my room full of "oh shit" stuff.

    All tubes mean EMP proof too.....

    Remind me to talk to you about this next time we meet.

  7. Dunno if you know this place: http://www.ehcknobs.com/
    It's easy to burn a lot of time looking.