I just bought a pair of Chinese graphite-plate 3-500ZG and they work
just fine. I think the Chinese have come a long way in their quality.
Not to give them a 100% pass, however, a few years ago we (our Agency)
had a 100% rejection rate for 6146's that our contracting personnel went
for low-bid despite warnings.

John N9JG wrote:
I am not sure if the Drake L4-B qualifies as a suitable topic for this
newsgroup, but it does use tubes and the power supply could be used as an
anchor for a small boat.

Are the Chinese 3-500ZGs a drop-in replacement for the Eimac 3-500Z in the
Drake L-4B?

John, N9JG