"A. A new 3-500Z costs around $150
B. The grids are not grounded in a TL-922.
C. I dont think there is top clearance for a 4-400"
The ham raising the question was not in the US and tubes may be more difficult
and expensive there. The fact that the writer was willing to put in a new
filament transformer to run one tube rather than two implied that purchasing a
replacement 3-500Z tube was not an option. I do not know his finances, but I
have been in countries where $150 is a years income for some.
No, the grids are not grounded directly, but pins 2,3 and 4 can be strapped
together and will work.
I thought the 4-400 is the same height as the 3-500Z. I have substituted
directly in the SB-220 with no problem.
Colin K7FM
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|