Yes, it's unusual, the only reason I can think of for that arrangement is so that the output valves can produce the maximum power that is possible with a 240ac derived HT supply, also the -ve bias derived from the oscillator would remain constant possibly.
Yes, a diode etc off the heater chain could provide bias but I'm not sure if silicon were generally available when that circuit was designed.
Lawrence. [EDIT: Whoops....missed Kalee's post...ships in the night and all that, so the above is a reply to Peters last post.
Yes, a diode etc off the heater chain could provide bias but I'm not sure if silicon were generally available when that circuit was designed.
Lawrence. [EDIT: Whoops....missed Kalee's post...ships in the night and all that, so the above is a reply to Peters last post.
