Re: big L

On 12/22/24 00:03, Dave Platt wrote:

In article <3faemjtve5hvghau2up1stdid1u3bq84gd@4ax.com>,
Cursitor Doom  <cd@notformail.com> wrote:
 

Indeed. And that's just one aspect of it. The designers in the early
stage of toob development deserve huge respect for the performance
they were able to wring out of a single stage - and all just to save
the hard-pressed consumer back in the day a few sheckles.

 One trick I've seen mentioned in a couple of books, was to use a
single tube section as an amplifier for two entirely different stages
of a radio or TV receiver.  The tube's grid was fed a combination of
an incoming IF signal, and audio output from the detector; the output
at the anode was fed to both the detector input, and to the audio
output (or a second, power-amplifier stage).  Since the frequencies
were so greatly different it was possible to use not-too-awful filters
to combine and separate them, and they didn't interfere with one another
badly enough to keep the system from working.
 Quite a different era from today, when they're talking about single
chips containing a trillion active devices!

In my early days as a budding electronics person, I played
with a television set that did that. The same tubes amplified
the video IF and the audio.
I also recall cheap toy walkie-talkies from the 1970s that
used a single transistor as both a super-regenerative
receiver and as a transmit oscillator.
In another thread just these last few days, Cursitor Doom
showed us a 1970s era Grundig radio that used the same
transistors for the 10.7MHz FM IF and the 460kHz AM IF.
I those days, transistors were expensive. Coils and
switches were cheap.
Jeroen Belleman