2nd Mixer and Matching Circuits Pictures

Homebrew DBM Mixer

The first diodes used were 1N914s, then switched to Schottky diodes. No difference in performance could be determined.

The main problem in building a homebrew mixer is getting the trifilar transformers wired correctly. Taking your time and being careful is all the advice I can give.

The cores are FT37-43.

An alternative is to use a commercial mixer, an SBL-1, SBL-3, TUF-1 or anything similar. I found no difference between the commercial ones and the homebrewed variety.

455 KHz Matching Circuit

The small ferrite core is an FT37-43, and the larger one is an FT50-43.

The output cap between the SFU445A and the output connector is a glass .01 capacitor. I got a bunch from Dan's Small Parts and like to use them because they look so cool.

The other caps are .001 monolithic caps paralleled to get .002 mfd.

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Last Update: 11-29-2002
Web Author: David White, WN5Y