In message
,
K7ITM writes
On Feb 12, 2:57*am, Ian Jackson
wrote:
In message
,
K7ITM writes





I've also seen a design where the modulator was single-ended but used
a push-pull transformer; the RF amp was fed its DC through the other
side of the center tapped winding. *That allowed reasonable balance of
the DC in the transformer, and worked decently.

Have a look at the Codar AT5
schematic:http://www.vmarsmanuals.co.uk/new/at.../www.vmarsmanu
als.co.uk/new/at5.pdf
--
Ian

Thanks for sharing that, Ian. The webpage says "1960's." You
wouldn't happen to know any closer than that, would you?

No really. It was just that the mention of the centre-tapped modulation
choke immediately reminded me of the Codar AT5 and the matching
receiver, the matching receiver, the T28. I used the pair mobile back in
the 1960s, and although such equipment is hardly up to today's
more-exacting standards, I had great fun with them. You occasionally see
the odd one (or pair) on sale at the various amateur radio rallies, for
around $50.
--
Ian