[Amps] SB-200 DATA

[jeremy-ca]

Im quite aware of the 80's problem. I was reselling Eimacs from CeCo, 
Richardson and 1 or 2 others before Richardson got it all. I even continued 
with Richardson for a few more years until I sold off Radio Kit.

I also had experience with those black base Russian 811's that Ameritron 
started with. I got a lot of repair jobs from those. I still have a pair as 
modulators in my Clegg Zeus where they are running well below ratings. They 
and the Chinese used receiving tube glass. I havent melted any lately!

I would hope that for the past 15 years or so Ameritron is using quality 
tubes from Eimac that have good life expectancy or is everything now coming 
from China?

One would think that ALL manufacturers would band together and push China to 
produce to original performance specs. The automotive tool industry has done 
this, including factory visits, and the quality from many factories is 
excellent. Ive placed several items on Snap On and MAC Tools trucks and get 
regular repeat business.

Carl
KM1H


----- Original Message ----- 
From: "Tom W8JI" <w8ji at w8ji.com>
To: <Amps at contesting.com>
Sent: Thursday, July 19, 2007 10:08 AM
Subject: Re: [Amps] SB-200 DATA


>> I buy around 50 a year and many still have original
>> 60's-70's date code
>> tubes and put out full power. I dont think that you will
>> ever see an
>> Ameritron or Alpha running that long on original tubes;
>> they push them a lot
>> harder
>
> That life part is true, but the reason you give is not.
>
> The fact is today we cannot buy tubes that are anywhere near
> as good or reliable as those made back in the 60's and 70's.
> Around the late 80's it really all started falling apart. In
> the mid to late 80's 8877's from Eimac were nearly all bad
> brand new (tube failures in MRI equipment nearly put ETO out
> of business) and Richardson's swallowed up Cetron and the
> rest.
>
> When Ameritron started producing the AL-572B they made a
> mass purchase of Svetlana 572B's, and the majority of new
> tubes were bad (and old) right off the shelf. The only
> alternative, largely due to Richardson's swallowing up all
> the manufacturing and pricing 572's out of reach, were
> Chinese tubes. The Chinese tubes were tested only at 1500
> volts or so and a few hundred watts, and the glass and other
> materials were far substandard to the old Cetron's.
>
> I can take 35 year old Cetrons that have been sitting up on
> a shelf and the majority high-pot to 8 or 9 kV, but about
> 50% of brand new Chinese 572B tubes fail at 5kV or less.
>
> The real truth is no matter how you run most modern tubes,
> the life on average won't be anywhere near the life of tubes
> before all the people who knew what they were doing retired
> or got fired.
>
> The problem doesn't stop at the food supply, anything that
> requires extraordinary care (like tubes) isn't as good as it
> was. That's the real reason.
>
> 73 Tom
>
>
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