[ARC5] Shuguang 211 tube

[Kenneth G. Gordon]

On 27 Mar 2016 at 16:58, Heinz Breuer wrote:

> regarding my BC-191 which is missing all four VT-4C tubes I found a
> replacement on eBay. There are new 211 made in China by Shuguang
> offered at about $50 each. I never heard of this company and wonder if
> anybody has any experience good or bad with these tubes.  vy 73 Heinz
> DH2FA, KM5VT 

I have had considerable experience with Shuguang's "572B" s...which aren't/weren't. I have 
zero experience with their 211s, however.

As far as their so-called 572Bs were concerned, at least 30% of them were bad right out of 
the box, and the other 70% always failed within a year after purchase.

I know: I bought I can't even remember how many pairs to keep my SB-200 in operation, 
and ended up tossing them all after around 1 year of service for each pair....and I was NOT 
"hammering" them either. I never allowed grid current to get above 25 mA per tube and kept 
power output to around 450 watts for the pair. The old Cetrons were rated at 50 mA grid 
current per tube and at least 600 watts output/pair. After about one year of service, the 
Shuguangs' grid current would suddenly drop and output would follow.

Shuguang finally sold the remainder of those really terrible 572Bs as "unsuitable for RF 
amplfiier use", mainly to audiophiles.

As I understand it, their 572Bs were so bad that Shuguang finally stopped making them 
entirely.

As far as the 211s are concerned, I guess for $50 each, you can get some experience with 
them.

Ken W7EKB
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