[ARC5] AM linear amplification

[AKLDGUY .]

Many thanks to those who have replied so far, all with interesting aspects.
Use of a very large tube in order to get a worthwhile power output while
not exceeding plate dissipation and Class B operation are of particular
interest to me.

I'm familiar with the 813 class of tube, being the owner of a RCA ET4332-B
transmitter at one time which used a pair of them, and although
they're sometimes available at swap meets here, the building of a 1500 volt
power supply is a bit further than I want to go (no suitable power
transformers).

Class B is interesting. It's not widely known that the 807 / 1625 is
capable of Class B zero bias operation, with screen grid connected to
control grid*. This configuration eliminates both the negative grid supply
and the screen supply. A pair of these tubes requires about 5.5 W of drive
power*, which the BC-230 can easily deliver.

*RSGB Communication Handbook, Fourth Edition, 1968, page 9.21-22

I'll look into this aspect. I had forgotten about 807s in Class B.

73 de Neil ZL1ANM
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