[sdiy] bottle ladder filter

[Peter M Blackett]

Dear Tim,
that seems like a most interesting project !
but I think you may need more that the 100 volts ht for the circuit to
work correctly.
But I know that means using a more complex heater supply as I think the
heater cathode insulation of the tubes [valves ]  may only be able to
stand 100 volts or so .
so you would need at least two heater windings ,not at ground potential.
regards Peter