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Re: [Amps] SB-200 DATA

To: "Tom W8JI" <>, <>
Subject: Re: [Amps] SB-200 DATA
From: "Roger" <>
Date: Thu, 19 Jul 2007 16:40:43 -0400
List-post: <>

> 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?

I recently decided to try a pair of the Chinese 3-500Zs just to see how 
they'd work compaired to the Eimac pair I have in the 2K4. So far they 
*appear* to be working well with the same output as the Eimacs, but only 
time will tell. Like other things, one pair is not enough for much of a 
comparrison let alone data for an anaysis.

I think I'm going to cheat and take the easy way out and go with the Tokyo 
HL-1.5Kfx, or the HL-2.5Kfx. Unfortunately with either one I have to give up 
something.  The 1.5 runs 1000 PEP out on HF and 650 on 6-meters while the 
2.5 is the legal limit on HF, but no 6-meters. The 2.5 is just a *tad* more 
price wise too<:-)) Then I still need to comeup with an amp for 6-meters.
> One would think that ALL manufacturers would band together and push China 
> to
> produce to original performance specs. The automotive tool industry has 
> done

The auto industry is a far larger pool than the portion of the electronics 
industry that uses this range of power tubes though.  Time will tell.


Roger (K8RI)

> 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" <>
> To: <>
> 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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