Bob wrote:
ken scharf wrote:

Early SSB exciters used the 7360 tube as a mixer / vfo so I know this
type of tube will work as a self excited converter. As far as pulling
is concerned this would depend on the difference between the oscillator
and IF frequencies, or the oscillator and signal frequencies. But
pulling shouldn't be any worse than with the pentode mixers that
coupled the oscillator to the same grid as the signal input. At least
the 7360 isolates the signal and oscillator to different electrodes.
Also the signal input is balanced and shielded by the screen grid.
OTHO I don't know how good (stable) an oscillator this tube is.
Probably better as a crystal oscillator than a vfo.

The very /best/ mixer I ever made used the 7360.

I tried several other types of valve ("tube" - U.S.) mixer, but /nothing/
came even slightly close. The isolation of the local oscillator from the
incoming signal, the conversion gain, the accuracy of balance and the
bomb-proof nature of the mixer made it superior to /anything/ else I've
ever tried. In my receiver, there's a font-end amplifier, using a
variable-mu pentode then the 7360. It handles a bigger dynamic range
than /any/ other mixer.

The VFO is a "Kallitron" type, using two FETs and a PIC-based huff-and-puff
stabiliser (in 10 Hz steps) and two bipolar buffer amplifiers to drive the
grids of the 7360. The PIC also drives an LCD display of frequency, and
frequency stability is spectacular.

I can assure you - /there/ /is/ /no/ /substitute/ for the 7360. Simply
don't consider /anything/ else. Professionally, I've worked extensively
on "H-mode" switched mixers - often using very advanced components - and
can tell you that the 7360 out-performs /everything/ else!

Chris

The very first ARRL HB I ever owned (1967) used the 7360 in the mixer
stage of a classic receiver (HB67) as well as another design (junior
misers dream). The first receiver was an 80 meter single conversion set
with a crystal controlled converter ahead of it. Similar commerical
designs were the HA350 and the 2B. The HB67 used a 6D10 compactron as
the first mixer/oscillator in the converter section. The MMD receiver
had the 7360 in the front end (NO RF stage) with a first IF of 3300 KHZ.
An RF Q multiplier was used instead of the RF stage. As you mentioned
the oscillator injected into the deflection plates in both cases