Bob wrote:
ken scharf wrote:

Sounds like you're building a receiver with only one tube in it (a 7360)
and everything else solid state. Then again the 7360 probably makes a
very good product detector too.

No - the RF amplifier stage is a variable mu pentode, and there are more
variable mu valves used in the IF, another 7360 for the product detector,
and the rest is solid state. The hybrid approach seemed best - for
example, the variable current drawn by the audio stages is /entirely/
isolated from the IF supply, the front end supply and the local oscillator
supply. At the moment, it's a single conversion superhet, with a 10.7 MHz
IF (because I have 10.7 MHz filters), though I'm considering making it dual
conversion, with a very high first IF, to improve the inherent image
problems.

C.

One project that I have been considering would be a re-creation of the
classic Drake 2B receiver. This receiver was a dual conversion 80 meter
receiver with an additional converter for other bands (making it a
triple conversion). The receiver covered 600khz of the 80 meter band
(3.5-4.1 mhz), the first IF was 455 khz, and the second IF was 50 khz.
I have several sets of IF cans from BC453 receivers (85khz) and a 2.7
khz Collins filter that could be used instead of an IF transformer for
the first IF.

I was thinking of using compactrons in the set, a single 6AR11 for the
85 khz IF, a 6D10 for the product detector and bfo, a 6AF11 for the AF
stage and S meter amp. A 6AG11 would serve as an AGC tube and AM
detector. The second (third?) mixer would be a 6BE6 (455-85), the
first and second mixers would be 7360's (expensive!). The first (xtal)
hfo would be solid state (maybe a pll), the second hfo (vfo) would also
be solid state. I have several nice three gang capacitors from ARC-5
receivers with dial gear drive that would work nicely. The completed
set would look more like the 2C because of the dial unless I ever find
another Edystone dial. (I had one in the junk box for a few years and
sold it on ebay to someone building an HBR. Got a kings ransom for it too).