> On Dec 21, 2025, at 8:16 PM, Brian L. Stuart via cctalk
> <[email protected]> wrote:
>
> So Santa had his sleigh out for some test drives tonight. For
> ballast (the real gifts won't be loaded until Wed night), he used
> a big stack of engineering drawings from the 1940s. Fortunately
> for us, his "spirited" driving included one turn that was too
> tight and out flew the drawings, where they landed on my lap. For
> anyone who's as eager as I am to geek out over 1940s computer
> design, I share them with you here:
>
> http://cs.drexel.edu/~bls96/eniac/drawings/
Wow.
I glanced at a few of them. Was surprised to see an inverter using a 6L6.
Then looked a little further and came across an element that uses an 807.
The 6L6 and even more the 807 are rather substantial power tubes. 807s are
commonly seen in amateur radio transmitters in the 1940s and 1950s, good for 50
watts or so power output. I have a couple, they are very nice tubes. I don't
remember the 6L6 ratings; 20 watts, perhaps? Both are also rather large, the
807 especially, when compared to typical "receiver" tubes.
paul
