Little 6V6 Tramsmitter

Hue Miller kargokult at PROAXIS.COM
Sat Jun 23 15:11:24 EDT 2001

While we're on QRP receivers, i  wonder if anyone cares to
comment on the ARRL's "How to become a  Radio Amateur"
booklet circuit, circa 1961, that used  2 6AQ5.   I read this
back then after building sets from Alfred Morgan's "Boy's
First Book of Electronics" (is that the right title?), and after
Morgan's typical breadboard construction i was appalled by
the level of metal work required for the ARRL project. No way
i could replicate that from junkbox parts, with hand tools, in
my bedroom.
Years later, i knew that with access to power tools, i  could
probably replicate the project, but i was instead appalled by
the choice of tubes: 2x 6AQ5.  I  still don't get it. MRL
literature explained the use of  such tubes as 3Q5 or 6V6
power tubes at low voltages to get more audio than with
other tubes, but this with  battery voltages on the plate, and
with only 1-tube circuits. I don't think in many years of looking
thru the literature of the shortwave age, i  saw another 2-valve
circuit that used a power tube as the detector. If you were going
to use a triode, for stability you used a low-mu triode, such as
1H4 ( Meissner kits) or 12AT7 (the AC powered kits), or if for
maximum sensitivity you wanted to go pentode, you used a
sharp cutoff type such as 6SJ7, 6J7,  32, or  34, or  6C6, or
6AC7, or 12AU6  (Philmore), or 6BZ6 (Knight Span Master).
But never a 6AQ5. Or was the goal partly to minimize number
of different tubes, such as in military gear?
This ARRL project had a matching transmitter, a single 6DQ6,
which looked like a more businesslike (that is, non-ham) Knight
T-50. If you could do a  good job on the metalwork, you'd have
a pretty darn good looking pair.
Anyone have a comment on the use of the 6AQ5 in the  ARRL
design? I mean reasoned opinion, not stuff like "Well if it worked,
why not" or  "No-code ruined ham radio", or "This thread is
ruining my life".
By the way, here are my ideas of some  nice simple HF rigs:
Midwest Electronics BA-80-40:   one 3A5.  Upgrade to 3Q4 (?)
2nd audio.
Mitey Mite: 12AU6 det.,  35W4 rect.,  50C5 audio -and- xtal
oscillator on transmit
"Tokyo Musen Handy Type"  (Japanese military WW2) 2 type
27 as regen detector and single tube vfo transmitter.
Regards, Hue Miller

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