WHY are electrostatic tubes wired so WEIRD?
 

Looking at the diagram of my 48-700, 50-701 and other Electrostatic-Deflect. type sets...It seems to ME...that the CRT in ALL of them is set up in a STRANGE way..

There does NOT appear to be a "2nd anode", at least in the way we are used to in most other tubes. like a 12LP4, 21AXP22, and about any M-D tube I have ever seen. . And WHY...does the HV seem to go to the CATHODE of the CRT--I am used to VIDEO being there--and at the most 250 volts or so. On E-D tubes...the HV, through some resistors seems to end up there!!

WHY...is this????

They do it to place the deflection plates closer to ground potential, to simplify the deflection amplifier design. They apply a NEGATIVE high voltage to the cathode end of the gun, which is effectively the same as a high POSITIVE voltage at the anode end of the gun.

This is (was?) a common arrangement for oscilloscopes.

Easier electrically to lower the cathode than it is to raise all the deflection plates.

Yet in other topologies like the Motorola VT-73, they do raise all the deflection plates with positive HV while keeping the cathode end of the jug 'conventional'.
http://www.earlytelevision.org/pdf/M...Sams-71-12.pdf

In scopes it was advantageous to have the high sensitivity deflection plates at or near ground, I suspect to avoid noise. TV's it's not an issue, those tubes probably aren't near as sensitive.

Plus it would be undesirable to have the usual hv decoupling caps in series with the deflection plates if decent low frequency (or dc) response is desired.

jr