4 Metre Converter - but which design?
Back in the mid 1960s I constructed a 70MHz/4 metre converter for use with my CR100, and I recall that it worked well. I am now trying to get it going again but have no circuit diagram. My guess is that that the design would have been published in an RSGB magazine (I was a member) but have no idea which one. I attach some photos below and would appreciate any suggestions as to what the converter might be. It uses three Nuvistor 6CW4 triodes for the VHF stuff and an ECC91 for the local oscillator.
Sadly the Nuvistors aren't too robust, with some of the pins having corroded through because of bimetallic corrosion with the cheap Cinch bases. But the internals are in fine condition safely inside an Eddystone die-cast box.
Any suggestions much appreciated!
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