[Moon-net] 8877 and YC236 questions

[Rob]

Hello to all
First question...
The tube YC236 by EIMAC is the same as 3CX1500/8877?
I have tried information on the web but I have not found null.
Another...
I'm constructing a W6SAI design amplifier. I have used for the resonant 
lines of the square tube of brass (25mm for side) in place of the round 
one but of the same dimension it is in length.
The decoupling capacitors are  2000pf  20KV , one for side. The problem 
is the resonant frequency
with plate tuning all open is about 130MHz. All the dimension are the 
same as the original design to part the lines that are square that 
instead round. Why dont work?
Sorry for my bad english
Rob IZ4BEH