RadioBanter - View Single Post

March 2nd 06, 09:48 PM posted to rec.radio.amateur.homebrew

Chris Jones wrote:

wrote:

hello,

I'm building my first reciver. I can't choose what kind of mixers
should I use. I have read that diode ring mixers are far superior
compared to dual gate mosfet mixers.

Is this true for both - first (RF / VFO) and second (IF / BFO) stages?
Or is there any real difference at all?

thanks

I have recently bought the books from the RSGB which contain all of the
Technical Topics columns from RadCom for the last couple of decades or so.
It seems like they really like making mixers from FST3125 Bus Switch ICs,
and up to perhaps 50MHz these are supposed to be much better than the
average diode ring mixer. They call the configuration "H-mode" and the
guy who I believe is supposed to have come up with the idea is called
Colin
Horrabin. Here is an article randomly selected from a google search:
http://
xoomer.virgilio.it/sergiocartoceti/pdf%20files/IK4AUY_%20qex_07-2004.pdf
I don't like the way they generate the LO signals with XOR gates but apart
from that it is interesting.

Chris

One thing I forgot: I7SWX I believe is responsible for many of the H-mode
mixer circuits in the the Technical Topics column.
http://www.qsl.net/i7swx/index.htm

Chris