813 tube with graphite or steel plate

[PA4WM]

Hello All,

Over the years of buying and collecting stuff...  , there are also two 813 tubes. One has a graphite plate, the other a thin "steel" plate. Both are RCA's

As far as I know, the thinner steel plate is a later production of the 70's.
I cannot find different specs for the younger tube.
Does the steel plate tube has the same specs as his older graphite brother?
My concern here is the dissipation rating.

73's Martin

[KM1H]

The thin metal plate will glow and melt just like a 811A when pushed beyond RCA specs. The graphite anode will take a lot of punishment.

There appear to be quite a few NOS Philips graphite 813's still available in Northern EU if US surplus is scarce.

Carl

[kb3ouk]

Should be able to find Russian GU-13s too, basically a Russian copy of a graphite plate 813.

[W2VW]

Metal plate models are sought after by those who spend extra money on sounds.

[K1JJ]

I've seen the metal vs: graphite effect in both 813s and 833As.   There's no doubt the graphite plates can handle abuse much better.  I have a pair of 833A metal plate tubes with quarter-size holes to prove it.

The metal seems to heat up very quickly, whereas the graphite appears slower.  Being "amateurs," this extra time to run for the breaker pays off.  


Dave, metal 833A's sometimes have spurious apostrophes.

T

[PA4WM]

Thanks for the replies.

I reckoned the metal plates 813 cannot withstand the "abuse" the graphite plates can. But their might have been different specifications for the metal plate version. Probably not, reading the replies.
I will handle it with care, when I'll use the younger tube.

On ham fleamarkets, we still see 813's overhere, but getting less and less. And the once that are being sold look like they have done some work...
NOS once are difficult.
(Off topic: ebay show them once in awhile, but the sipping costs from the US to EU are riduculously high... )

Anyway, I will treat my 813's with care. The metal one even a bit more...