Friday, April 1, 2011


This transmitter was designed around the Taylor T21...which is a 6L6 with a six-pin base. Another, similar bit of 6L6 cloning was the Raytheon RK49. (There's a top-view photo of the little transmitter in the "Radio" handbook for 1940 -- I'll see about scanning it this evening.)

There is a reason for this: the 6-pin base has wider spacing between pins and will run higher voltages with less chance of an arc-over. Especially important at radio frequencies. The Raytheon appears to have a ceramic base. I'm not sure what Taylor used.

In most HF applications that aren't pushing the tube too hard, you can substitute a 6L6G/GA/GB for these tubes without much trouble.

BTW, these things can become quite valuable -- there's a Utah "Junior" single-6L6 transmitter, albeit a very fancy one, about to change hands for over $500 on an auction site.

Update: Bruce, W1UJR, points out in comments that it's more fun to restore a Utah Junior than buy one bandbox-new. He's right -- and has done a first-class renewal on his.


  1. No sell on the Utah, nice set and all, but $500?
    I restored one a few years back, cute little set, but you'd really have to love it a lot to pay that much.

    Nice to read along.

    Bruce W1UJR

  2. I was stunned at the price -- it was in remarkable shape, but still, I only paid 4X that for my car!

  3. Ah, but the buyer misses all the fun of restoring the set.
    Now this is fun!

    73 Bruce 1UJR

  4. Wow! That's a grand job of it. Very fine work. --How's it and the FB-7 on the air? Looks as if it would be a lot if fun!

  5. Good question Roberta, I've yet to use both on the air. Nn fact, I keep thinking I need to set up a nice 1930/40s station, period desk QSL cards thumb tacked to the call, bead board on the walls, just like we see in the old radio magazines. The house is too small, so I've actually thought about building a small room right inside the board for this purpose, big knife switch on the wall for T/R, switches build into the desk, the whole set up. We'll see what summer brings. Enjoy your blog, glad I was able to find your postings again, its been a long time since the old glow bug days.

    73 Bruce