[Boatanchors] 6146 USED IN BOATANCHORS

[Magoo]

I have an HX500 in which I installed a pair of 6146Bs to replace a pair of
6146As which had gone somewhat soft.  Everything appeared to be fine until
one day, sitting in standby mode, the plate current went to the pin and blew
the P/S fuse.  This continued every time I tried to use the rig...once the
tubes got nice and hot the parasitic (for that is what it turned out to be)
caused the final to go crazy and blow the fuse.  Most frustrating!

I tried a number of things to cure it, but after reading Glenn Zook's
treatise on the 6146, I installed a pair of NOS "plain jane" 6146 tubes and
the parasitic which was causing the problem disappeared.  It would appear
that the difference between tube types (inter-electrode capacitance) threw
off the neutralzing circuit enough that it was just on the verge of going
wild even when proper neutralization was indicated.  Nowhere in the manual
does it specify the use of only the 6146 or "A" variant.....some things we
learn by accident I guess.

Bill, VE3NH