Hi Gary,
Are there any circuits available for this type of transverter please ?
Unfortunately no... only a few photos, since I never made a complete
drawing. I built the transverter stage-by-stage, and made a few
handwritten notes here and there.
A few photos are here:
http://freenet-homepage.de/dl4yhf/lf_trans.html
(quite outdated; the preselector has been replaced with a 4-pole version
since then).
The discrete Schottky ring mixer (using 4 matched BAT42's or similar) is
driven with some ten milliwatts from the 10 MHz OCXO, but an IE500 or
similar would be easier. The same mixer is used for RX and TX. Besides
that, there is an HF VOX for the RX/TX switching, driver, and final with
four MOSFETs running at 12 Volts DC. But today, I'd use a higher voltage
for the final, since 24- or even 48 V SMPSU are easy to find these days
(even without built-in LF QRM generator ;-)
73,
Wolf .
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