"Michael Black" wrote in message
ample.org...
On Tue, 5 Aug 2008, Tio Pedro wrote:

There were plenty of articles about using the other but cheaper
tubes similar to the 7360. But I'm not certain any I saw used
them as a first mixer. One could go back and check. And if
that's the case, either everyone just copied Squires 1963 article,
or there actually was a good reason to not use the cheaper variants
for the first mixer.

MIchael VE2BVW
Hi Micheal

Most of the magic seems to be being able to generate push-pull LO
injection for the deflection plates, that along with the P-P output tank
balance, is critical for max. signal rejection at the mixer output. I do
have
a 1600kHz daytimer next town over (1st IF is1600 kc.)

I was thinking of using a trifiliar wound balun, driven by a cathode
follower
buffer of off the first LO, to provide the 3 volt RMS injection to the
deflection
plates. That should provide balanced drive voltages to each deflection
electrode? Squires never provided a lot of
detail on his coils or how they were made. A balun might provide a modern
solution for balanced P-P injection from otherwise single ended LO sources.

Pete