Re 572-B

[Bob Meyer]

I did some looking.You could use 811A in SB 200 but you 
will need to cut plate volts.
You can do this buy un hooking 1 diode bank in PS and move HV winding from the center of 6 caps to the - side of PS.
This will give you 1/2 plate volts.
power will be less but will not kill the amp/tubes.
also keep ypur drive down.
Your plate will be around 1250 volts.a little low for 811A but will work to test amp.
1250volts is CCS rateing on 811A..175 amp plate current per tube max.

buy just putting in 811A tubes you will exceed the plate volts and the idel current will be too high.It may even arc inside the tube.If this happens you may blow power supply and even plate choke.

Just un hook V dubbler and run 1/2 wave plate supply.
Doen't have a SB 200 in shop to try it.should work,,

73's
Bob

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