Unknown amplifier with Philips F443 pentode (Gezocht)

door adamgol , 16.10.2023, 01:05 (405 dagen geleden)

Only a few devices were built with the giant F443 pentode. Thanks to it, power up to 25W was obtained. I am presenting an unknown amplifier from the early 1930s, containing two F443 tubes. The device was manufactured in Denmark by Bofa - Struer, cooperating with Philips. In my free time, I will try to recreate the electrical diagram (I devote much more time to old TV sets). Apart from two F443, there is one REN904 and 3x barretter 0.72A.38-114V model C21. I haven't found the latter in any catalogue. Maybe someone has information about C21? Philips was probably the manufacturer. Amplifier circuits with the F443 tube or its successor, the F443N, are welcome. Thanks,
Adam