[Amps] Chinese 3-500 tubes what manufacturer?

[chasm at texas.net]

Rob Atkinson wrote:
> Gary,
> 
> I have a pair of Chinese 3-500s in my ten tec Centurion.   I got them
> from RF Parts a few years ago so I don't know who the Chinese mfr. is
> but I imagine if you called RF Parts and asked them they would tell
> you.  I have run mine with no problem in the Centurion at 800 plate ma
> and around 3.1 KV, maybe 2.7 or 2.8 KV full load and getting 1.2 or
> 1.3 Kw pep.  they have performed very well.
> 
> 73
> 
> rob  / k5uj


my understanding from this and other lists, tubes made 5 or 10 yrs ago 
are completely different quality from those made today
I would be quite interested in where to get good quality tubes today.. 
dependably so, .... wonder about those from diagnostic medical 
machines, do any of them use this tube?

thanks
chas  k5dam