Re: HB: Mixer Puzzle


From: Monty N5FC (
Date: Sun Jun 10 2001 - 19:52:05 CDT

On Sun, 10 Jun 2001 09:11:51 -0700, QRP-L, Bob N6WG wrote:
>My guess is that you have somehow configured the diodes in the mixer as a
>full wave rectifier. A FW rectifier puts out twice the incoming frequency,
>making the rectified input signal easier to filter.
>You might want to review the mixer wiring and see if it is consistent with
>other rigs using such a mixer. 73, Bob N6WG

Cool, Bob! You get the Ceeegar! In fact, I had two diodes backwards,
forming a nifty full wave rectifier (and still acting as a mixer -
HI). Turned them around, forming the correct configuration for a
diode-ring mixer, and now I get the expected beat notes.

However, all is yet not well... I still have about 20-30 db losses through
the mixer. However, this shouldn't be too hard to chase down... either I
have the trifilar transformers mis-wired, or my matched 1N5711's ain't what
they should be.

Any other ideas?

monty N5FC

Monty Northrup, N5FC
Austin, Texas
web page (ham radio):
web page (home):

Search QRP-L Archives

[ QRP-L Archive | ]
[ 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 ]


This archive was generated by hypermail 2b29 on Thu Jun 28 2001 - 10:18:01 CDT