I have two 3-500Z tubes made in China by Pride and branded with big red
Ten-Tec logo. Ten-Tec used them in their Centurion amplifier, but I ran
them in an old Heathkit SB-220. One of these tubes developed a filament to
grid short. The other one is in excellent shape.
These tubes have metal plates, not graphite. They have vertical fins. I
bought them from Ten-Tec in 1996. They probably have 200-300 hours on them
and I run them easy (like 600 watts output from the pair -- CW only and I
don't have much to say). I phoned Ten-Tec to see about buying one
replacement but it was gonna cost almost $200 for one tube, so I replaced
them both. Now I have an extra to shed myself of.
$100 for either one you want or $102.50 for both. Add to that maybe $5 for
shipping.
73, Mike N4NT
|