50-MHz Transverter

With all of the new HF transceivers including the 6-meter (50-MHz) band, it has grown to considerable popularity.  I have entertained the idea replacing one of my Kenwood TS-930SATs with one such radio, however none that are contest-worthy on the HF bands have shown up in the $500-$700 price range, second-hand or new.  So, I set out in the Spring of 2010 to construct a transverter to use with one of the TS-930s.

The heart of the transverter is the article “A 3-watt transmitting converter for 6 meters” from the 1993 (and other) edition of the ARRL Handbook for Radio Amateurs.  The PA is a direct theft of the Elecraft XV50 PA using the Mitsubishi RA30H0608M module.  On the receive side, I cobbled something together that seems to work based on bits from a variety of sources, including the 144- and 220-MHz transverter and MOSFET LNA articles from the same Handbook, and Experimental Methods in RF Design.  This article will serve as a starting point for accessing the detailed circuit schematics and technical details that are not addressed in blog posts on transverter work.  I expect it will be a bit more complete.  Furthermore, this is one of those projects that I would not encourage anyone to duplicate as I have constructed it.  However, there may be useful features.

Like many projects around K8GU, interest in the 50-MHz transverter waxed and waned, reaching zenith in June 2010, before taking a precipitous dive when transmitter performance appeared to be poor based on a crude oscilloscope measurement.  The project was revived in July 2011, when I borrowed a nice spectrum analyzer from work for another project.   I was able to quickly diagnose the problem (shorted subminiature coaxial cable) and peak the transmitter BPF in a few minutes.  I then set about packaging the transverter and interfacing it to the TS-930.  During the CQ WW VHF Contest on 16-17 July 2011, I was able to make the first few contacts with the transverter operating at 200 mW.

See all blog posts related to 50-MHz here.