John Walton wrote:
The question wasn't so much ZENER so much as it was BIAS -- the
LM317HV or TL783 will go much higher than an LM317.

The original question was specifically about cathode bias for a
grounded-grid power amplifier. That application requires a two-terminal
shunt regulator like a zener diode.

If there is a way of configuring a 317-family series regulator and a
power transistor as an adjustable two-terminal shunt regulator, I'd be
genuinely very interested to learn about it.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek