RadioBanter - View Single Post

November 29th 05, 02:17 PM posted to rec.radio.amateur.boatanchors

wrote:
it is sort of odd that they used the fancy, but expensive,
7360 balanced modulator tube.

That was an extremely common choice for not only for not only
transmitter balanced modulators but also for receiver mixers and
product detectors in the 50's and 60's. I think it must've been the
case that one early ham article used it and everyone else copied it.
Certainly it was not a common junkbox part...

Tim.

Hi Tim,

ARRL published a circuit using it in many of their handbooks from the
'60s. And I have heard that it was used in TV applications, but the
part that surprises me is I have only seen one type, the 7360. If it
was such a commonly used tube, it surely would exist in a non industrial
numbered version (eg. 6ZZ9, or some such).

The reasons for wanting such a tube are easy to figure out. It can
easily give 60dB of carrier rejection... add a xtal filter, and 80db
is easily achieved. Compare that to a diode dbm, and its 30db, and
50db capabilities.

-Chuck