LF: 472/500kHz 10W transverter

[Roger Lapthorn <rogerlapthorn@gmail.com>]

This evening, my WSPR tests are with the latest version of my homebrew transverter, designed to be used with QRP rigs like the FT817 in "split" mode. The transmitter operates around 3.7MHz and transverts down to either 472 or 500kHz. On RX, the transverter simply passes the RX signal through to the FT817 which is used on 472/500kHz. This makes for a very simple yet effective design.

I reverted to a double balanced mixer (SBL1 or ADE-1 or similar) for the TX mixer and this has made the design very stable and reliable now. The PA and ATU coils are air wound in the GW3UEP style on 22mm PVC pipe. The whole unit fits in a small plastic box.

Already WSPR reports are coming through from PA, G, GW despite the use of my short vertical tuned against a copper water tank ground and resonated with a tapped coil on a ferrite rod. Signal levels from some suggest CW QSOs should be OK.

Details of the transverter are available on my website and on my blog at <http://g3xbm-qrp.blogspot.co.uk/2012/09/472500khz-transverter-finished.html>.

I hope this little circuit encourages a few newcomers to try the new band in due course. For now tests continue on 500kHz and further reports would be much appreciated.

73s
Roger G3XBM

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