70MHz Transverter GW4RWR

This Meon was orginally built in 1988 as a 50MHz receive converter for a university project on meteor scatter propagation to monitor bursts from Eastern Europe. It saw service on transmit from about 1989 and was subsequently retuned for 70MHz in 2006. There's nothing remarkable about my transverter, but I'm including this page just so that you can see what I use on 4m.

For any readers that are not familiar with the Meon design, its receive converter is a BF-961 feeding a SBL-1 mixer, with a BF-960 follow on stage at 28MHz. The receive converter is clearly less noisy and more sensitive than the Yaesu FTV-707 that I once had. I've added a resisitve pad on its output to reduce the converter gain to a minimum.

On transmit, 1mW drives the SO42P mixer, and a BF-961 then drives a 2N3866 to about 100mW. I follow this with a TAIT PMR PA module, which was already tuned for 68-80MHz, and needed only minor work to make it into a 15W linear amplifier.

Excuse the untidy wiring. When the meon is off, the +8V on TX from the transceiver is fed back to the transceiver to enable its own PA. There was also an 'overdrive' -ve voltage fed back to the primemover ALC line at one stage. The on board PCB relay switches the PTT out for the valve amplifier.

I'm not using that relay for antenna port switching. Rather separate N-sockets connect the transmit path directly to the valve amplifier input, and the receive converter is connected to the amplifier antenna relay to minimise any losses. I was also keen to avoid routing the 15W so closely to the meon final stage.

The lousy SO-239 carries 28MHz output, and 28MHz input on the even lousier phono socket. These different sockets are only chosen to make it more difficult to connect up wrongly - idiot proofing.