[Amps] Tube substitute in a Hallicrafters HT-41

[John Finner]

Going in a different direction, a pair of 4X150A/4CX25B's in 50 ohm passive grid AB1.  Tubes are cheap and plentiful.  Anode load impedance, anode supply voltage, filament voltage and bias voltage supply need little or no change.  A zenior screen regulator off of the anode supply and cooling air need to be dealt with.  Looks like plenty of room for the sockets.

Since the HT-41 has no tuned input, a 572 conversion would be more complex.

John
WA4EPI