In article , K3HVG wrote:
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.

Depends on the tube, basically. The 3-500Z is a well-implemented design,
but the 6146es still don't meet original spec. And the Chinese 6550
specifically says on the data sheet not to put more than 250V on the plate,
which effectively makes it unusable in anything designed for the 6550.
But on the other hand, the Chinese 211 and 833 tubes seem just fine.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."