Ken Sharf Wrote:

Back in the 60's, there was an early direct conversion receiver that
used two 6SB7Y's in a balanced circuit with a B&W phase splitter run
bass-ackwards and an rf phase splitter in the vfo. This was actually
a single signal receiver using the idea of a phasing sideband modulator
in reverse. Today we'd call it an image-reject mixer.

What's old is new again.....


I remember that one !! Seems to me, it was in Single Sideband for the
Radio Amateur and I was really tempted to try to build one.

Actually, I was responding to the original request for a direct conversion
using NPN transistors. There are a lot of designs for direct conversion
rigs, and some of them are excellent.

Personally, I like the designs by KK7B and if someone wants to try their
hand at it, the Kanga website has some kits available.

http://www.bright.net/~kanga/kanga/KK7B/minir2.htm

They also carry the R2PRO which has excellent characteristics

http://www.bright.net/~kanga/kanga/KK7B/r2pro.htm

I've homebrewed from scratch some direct conversion breadboards over the
years, but these are image reject and would be a good starting point for a
complete transceiver.




Jim
N6BIU