John Rabson

I seem to recall a question in my IEE (1966?) fiinals which asked me to outline the design of a 1kW transistor AF amplifier. I asked a neighbour who worked in semiconductor research if the examiners were serious. He declined to discuss the matter.

John F5VLF

On 1 Aug 2022, at 16:19, Dave New, N8SBE <n8sbe@...> wrote:


As used in the Elecraft KPA-1500 (two of them, which gives a great deal of overhead).

And I do have CK-722's.  They came in a small plastic case I purchased at the Radio Shack in 100 Oaks Mall in Nashville, TN back in the early 70's.  There were a small quantity of Silicon NPN and PNP and Germanium NPN and PNP transistors.

I bought it to complete my first attempted homebrew receiver project which was a regnerative receiver for 40M.  Never did get that thing to work, and I progressed from there to building a Heathkit HW-101 using my saved-up lawn-mowning money.

My Novice station was a used Hallicrafters SX-99U with outboard Heathkit Q-Multiplier, and a borrowed Knightkit T-60.


-- Dave, N8SBE (Novice callsign WN4SBE in 1970)

Quoting Mark <venchant@...>:

Hey, do you think we'll get a surface-mount 4CX1500?



Jim, I have a single GE-2 that I'll trade you for a good 4CX1500.  Might get a watt out of it in pulse service. I did have an AM amp using pulse rated 4-1000A's a couple decades ago.  One RF amp, the other cathode modulated the top tube.  Modulation transformers were much more expensive than the tubes.

I digress.  I never owned a CK-722 but thought they looked neat.

73!  Mark K9TR

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