Comments on: QST Magazine in the 1940s

By: Terence Barker

Terence Barker — Tue, 07 Dec 2021 02:11:11 +0000

Looking for a copy or pix of my dad’s ham station on the cover of QST in the mid 40s. His name was Walter or Wally Barker

By: Theron Gough

Theron Gough — Mon, 11 Dec 2017 17:43:16 +0000

Is there an interest in Old QST Magazines from 1937, 38 and 39. I have a complete year of each.

By: gururaj k s

gururaj k s — Thu, 26 May 2016 10:42:16 +0000

The 6F6 is a true pentode and gives a high. gain by prewar standards with its high load. It also makes a good buffer for a hf vfo. I have read that it is microphonic sometimes . As high mu triode it can be used as a harmonic generator.

By: Ron AC7AC

Ron AC7AC — Mon, 28 Apr 2014 02:54:50 +0000

My Ham “career” started about 1950. The 6F6 was very common then in most handbook circuits, but by then the beam-power tubes (6L6, 6V6, 50L6, etc) had eclipsed them with their greater gain and efficiency, so I never used on in a new design. The cathode-follower was a common option for a low-impedance driver transformer.

By: Sundowner

Sundowner — Wed, 29 Aug 2012 02:05:29 +0000

Pete Millett has a lot of this old stuff for free as downloads on his web site. I have several old radio and audio books my father left me. Look for the old Ghirardi radio books, the Shea’s Amplifier Handbook, and the Professional Broadcast Engineering Guide, plus the Audio Cyclopedia and Newitt’s High Fidelity Techniques.

A lot of the audio stuff has been reprinted by Ed Dell’s Old Colony Sound Lab. The sttrictly RF stuff is still cheap at hamfests.

By: Bafflegab

Bafflegab — Tue, 28 Aug 2012 05:12:42 +0000

All good AM transmitters until the 1950s and most tube ones thereafter used plate modulation with a modulator that was nothing more than a big old power amplifier, with an output transformer specially designed to provide the proper reflected load (in the several thousand ohm range usually) and stand off unbalanced DC in the secondary.

But. Those modulators were designed to run at high peak to constant load ratios. Few used negative feedback, which is necessary for fidelity, and they were NOT very good high fidelity amps. They’d work OK for PA purposes if the modulation transformer had another winding or was strappable for the needed load, or were replaced, but are generally nothing to want to copy today if you aren’t building a vintage AM ham station.

The ARRL books are a great reference but the modulator designs are not good amp projects.

By: Brad Rinkert

Brad Rinkert — Wed, 19 Oct 2011 05:52:51 +0000

The best first project using tubes anyone can build is a 1930s or 40s style regenerative radio. You have to wind the coild, but that’s a feature, not a bug. It’s simple with a homemade winder.