Mr. Land wrote:
Thanks for replying.

WB is OK, I just get the bright blue splotch that goes away after a few
minutes.

Interesting: the emissions can be measured? Is that done via an
equivalent current measurement?

Regards...

You put a micro/milliammeter in series with each of the cathodes and
urn on the guns one at a time, or there are tube checkers that can do
the same thing. Another possibility is to raide the filament voltage
of the blue crt slightly to raise the emissions. Depending on the set,
you can add a few turns of wire to the horizontal output transformer
(HOT) and put them in series with the filament voltage if it is derived
from the HOT, measuring the voltage as you add the turns. IF you get
the connection so that the voltage decreases, you must reverse the
connections. A lot depends on how familiar you are with tv set guts.

H. R. (Bob) Hofmann