[Amps] Re: Finals will not neutralize Just how good are

[Will Matney <craxd1@ezwv.com>]

Peter,
Although Svetlana and other foreign manufacturers claim that their tubes 
are direct replacements, under careful comparison, they have some slight 
differences. These include gain and interelectrode capacitance. When it 
comes to actual replacements, sometimes this throws the tank circuits 
and any other tuned circuits off (neutralization circuits). Some even 
need different bias and screen voltages like the 572B by Svetlana. The 
EL-519 by Svetlana is really a 6P45 and is not a real 6KG6 or 
EL509-EL519. Svetlana does have a good tube as they were designed around 
military use where Russia didn't care to spend money for the them. I 
think you'll find that Svetlana will last as long as Eimac with about 
1/2 the cost or less. You may have to do some tinkering though to match 
everything up.

Chinese tubes used to be terrible when they first come on the scene. If 
you get ahold of NOS Chinese tubes, you could get a bad one. If you get 
the newest imports, they are actually quite good. The reason being is 
the quality was so bad at first, nobody would buy them so they HAD to 
change them. Their 3-500ZG is as good as Eimac in my opinion now. They 
are makingthe 6146B, 6550, and several other audio tubes. I spoke to a 
manufacturer there about one year ago. I was asking them if they could 
build the 6LF6 again which they had before. They will do it but there 
was too large ofa minimum order for myself to swallow. The 6LF6 could be 
used to replaceabout every 12 pin compactron sweep tube ever made! All 
those old Yaseu 101-B's with the 6JS6 could cross to them also. I wish 
that at least one importer that had the capital would get these, they 
could make a fortune.I have had good experiences with the new 4CX250B's 
and 3-500ZG's that come out of China also.

Keep in mind that there is still a good stock of U.S. made NOS 6146B's 
yet. The price is a little steep but if that's what you want, they're there.

The truth about what caused all of this was due to one company. 
Richardson Electronics bought the last vacuum tube plant which was G.E., 
located in Owensboro, Kentucky. They done this without any fan fair in 
the news. Without any warning, Richardsons stopped all the manufacture 
of glass tubes and made MPD (formerly G.E.) do microwave, and military 
tubes strictly.It left everyone holding the bag who was using them. They 
were the very one who started raising the prices across the board to all 
these high prices also! Keep in mind that Richardson also owns the 
majority of Eimac and Amperex as I understand it. Talk about a monopoly 
that the U.S. Government allows........

Will Matney
US Amplifier

"The subject line says it all. I've read a few posts that cite problems
with stability and parasetics pronlems with foreign tubes.. I have a FL 
2000 that I would like to retube but I'm afraid....... I sure would not 
want to 'test' these tubes in my beloved TS-820....this my 'Baby' among 
my 7 boatanchors!Anybody have firsthand experience with these tubes?
What about the Chinese 6146's...I've heard  things not soo good.
I think that I'll go the 6883 route . I don't mind modifying the
transceiver a bit.....after all I bought it to transmit not to sit in a 
'Collection' .   My wife uses her antique furniture in the house ....I 
usemy  boatanchors or they won't stay here. I'm not running a museum. 
Thoseelectron have to move in my shack!
73's
VE2FAR
Peter"


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