TW Electronics 1958 - 2000
TW 70cm A2521 Converter
This converter used a GEC A2521 grounded grid triode in the RF stage with a 6DS4 nuvistor in the mixer stage rather than the usual diode mixer, thus providing some useful conversion gain.
All brass construction was used and this was silver plated for optimum performance and a choice of I.F. was available. For the full specification look at the TW leaflet for this product here.
The photographs below (all courtesy of M0WQR) show an earlier version of this converter than the one mentioned above (note there is only one nuvistor but four 'bottles' in this version).
The crystal is a 35.0000Mhz and the oscillator and multiplier chain was 35, 105, 210, 420Mhz, with the I.F. of 12-16MHz giving the 432-436MHz coverage.
Tom Withers (who identified the unit) said " The entry is dated 13/8/64, almost 46 years ago; no wonder I cannot remember much about it. We did not sell many but it was a very good performer ".