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Author Topic: Johnson Thunderbolt Power plug.  (Read 26427 times)
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WQ9E
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« Reply #50 on: August 16, 2010, 07:06:55 PM »

Slab,

The Pacemaker seems to have a horrible reputation but mine was easy to restore and has held its alignment properly for four years now.  Paired with a RME-6900 it makes a decent all mode station.  The only unusual problem I ran into was a coil with a wire strand intermittently shorting to ground which took a little searching to find.  You do have to ride the VFO a bit to counteract the drift but it is still better than my Eico 753.

These low drive linears are fun to play with and I made a few contacts using my QRP Yaesu FT-817 driving a KL-1 Chippewa.  The 2E26 is a neat little tube, it looks like a compact 6146 and seems to have been more popular in homebrew designs than commercial.

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Rodger WQ9E
The Slab Bacon
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« Reply #51 on: August 17, 2010, 07:54:17 AM »

Rodger,
          The 2E26 IS a neat little tube!! Terribly oerlooked by builders. I think of it as 1/2 of 6146. 2 can make 55w of audio in shove-yank with no problems if you push them into a little grid current (AB2). They used a lot of them in older low powered commercial 2-way stuff, and they are pretty good for VHF stuff as well. They are cheap and plentiful, I have a 5-gallon drywall bucket full of them. You can also plug them in in place of 6146s in older 100w rigs to reduce the outpoot to drive a leanyour. Usually they can be plugged in with no circuit mods, making a nice, easily reversable modification.

Clark,
        I / we didnt say they only did 100w, we said somewhere between 150-200w.
I know, I've had one for many years. I've ran it up to 350w or so, and it wouldn't make any positive peaks, not to mention not sound very good. I found 200w was a comfortable operating range.

Unlike class C where you can easily see 60-70+% plate efficiency, in leanyour service expect to get somewhere around 33%. That is why linear AM was not very popular back in the days of the 1kw DC input power limit. Why run 330 wats when you could get 6-700w out in a plate modulated rig. That is also why big screen or cathode modulated transmitters werent built. It was a plate efficiency thing.

you really seem to like the T-bolt, as a novelty rig they are pretty kool, but I just cant get serious about one. If you changed out the plate tank, and ran the Ep up to 3000-3500v they would prolly kick ass and take names. However if a bullfrog had wings, it would never bump it's ass!!   Grin  Grin

It is a shame you dont live closer, I would give you my T-bolt, that way you could have one to szht on and one to cover it up with  Grin  Grin


                                                         The Slab Bacon
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"No is not an answer and failure is not an option!"
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