[TenTec] Centurion Plate 3-500 question

[Mike, K9UW]

I recently obtained a used 422, complete with two Eimac 3-500Z's that 
were shipped separately.  While unpacking the tubes, I managed to 
destroy one of them when it slid out of its tube of bubble wrap packing 
and bounced on the floor. Fortunately, the kids were not home when this 
happened, as the air in the shack got a bit blue before I calmed down.  
The surviving Eimac is now for sale, in case anyone is interested.

Sickened by the experience but determined to get this amp on the air, I 
ordered a pair of 3-500ZG's from RF Parts which, I'm told, are the same 
3-500's that are being shipped with the new Centurions..   They arrived 
this afternoon, but I was surprised to find that the plate caps on the 
new tubes do not match the plate caps on old Eimacs. 

The old tubes had a slender shaft (~3/16 x 1/2") that poked out of the 
top of the tube and Ten-Tec provided a plate cap heat dissipator that 
fit over it.  The heat dissipator included a screw that secured the 
plate connecting straps.

There is no way that the heat dissipator will fit these new plate caps.
 
Has Ten-Tec come up with a new means to attach the plate connecting 
strap to the plate caps on these new tubes?  The new tube's plate cap is 
bell shaped and appears to be set over the same slender plate cap that 
the Eimac tube had, and this bell-shaped cap seems to be attached with 
some sort of set screw. 

A call to RF Parts got me a conversation with a receptionist who could 
not find the Tech Support person, but she advised against trying to 
remove the bell-shaped cap to get at the slender cap inside of it.

My guess, at tis point, is that Ten-Tec has redesigned the plate cap 
dissipator, but this issue has cropped up after they're closed for the day.

Can anyone offer any insights? 

Mike, K9UW
Sleepless in Amherst, WI
k9uw at wi-net.com