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Saturday, 3 January 2009

PSK TCVR - KD1JV design

I have had a few emails from Turkey, US, Australia and a few other places about the build of the KD1JV psk TCVR as posted originally here . I took this to the initial HOGCON meeting and was one of my show n tell pieces. I am going to repeat the build and document it for 20m, 30m and 40m. I have the crystals for 40m and 30m and I think I have a 6.144MHz crystal for 30m. (I think mixing 4.9152Mhz and 12Mhz might also work for 40m in addition to the 4MHz and 11.059MHz KD1JV suggested)

W8DIZ recently sent me a bag of the IF transformers: 42-IF123-RC KD1JV used so I will have the same as he used rather than the alternatives used in my build.

Hopefully the new builds will address the original issues that occured for some with the mixing of the 5.068MHz oscillator signal, the setting an off set, the value of C36 that I found to work and the values for R36 and R37.

In addition to the PFR-3 which is a cw 20m/30m and 40m rig I will then have a psk setup for the same bands.

Anyway here are the three boards fresh out of the etch tank. I have rubbed away some of the etch mask so I could see the copper tracks underneath. The dark spots are where I used CD pen (resistant the etch) to cover small spots in the mask due to a bit of dust being on the copper when I ironed on the Blue Press N'Peel film. As an experiment the two on the left have a solid ground plane the one of the top right is single sided.

Peter at Jabdog has the 6.144MHz crystals for the 30m that will arrive soon enough so will drill the boards and start mounting components. I might start to document the builds as if it were a 'proper' kit build as I believe a few are interested in the design.

More to follow.