Insulating Output Tank Cap

[Steve W8TOW]

Hi Gang, rebuilding one of my HB tx. A pair of Taylor
T-40's in PP modulated by TZ-40s.

The original circuit used a dual 100 pF cap with pretty close
spacing, mounted above the chasis to prevent arcing.

This worked pretty well until I put it on 160m.
Within a few months of use, I started having flash overs
on "un-keying" the mic in one section of this cap.

The circuit uses a B&W TVL 160 with 50 pf door knob padder for
more "C".
B+ comes into the deck and a 500 pF cap (with one side to ground) is
mounted on the bottom of the R154 RF Choke... (aobut 1250 VDC)

The choke is connected to the center of the TVL160 naturally.

Here is the question...

To correct the problem, I've installed a new 200/200 dual cap with double
the spacing...(good for about 5KV) Insulated above chaiss...

Many of the old books show the B+ at the bottom of the
RF choke connected to the ROTOR of the plate cap AND
B+ also going to the coil...

A 500 pF to .002 uF cap usually bypasses the STATOR....

Any thoughts about this...will this prevent flash overs as the old masters
say???
73
Steve
8TOW

[KC2ZFA]

I think the second-to-last paragraph in the Technical Tidbits section of

http://n4trb.com/AmateurRadio/GE_HamNews/issues/GE%20Ham%20News%20Vol%2003%20No%205.pdf

provides the answer...

Peter