I don't think we're talking power out, but rather long-term reliability. At the
time I had the two pairs of RF Parts 3-500ZG's they were touting how they had
the factory running to meet their manufacturing criteria. They had done a lot
of work to improve the factory's product to meet their requirements. Maybe
this is all old news now.
73, Duane
Duane Calvin
Sent from my iPhone
> On Aug 11, 2014, at 12:41 AM, George Fritkin via TenTec
> <tentec@contesting.com> wrote:
>
> A couple of years ago I decided to replace the Eimacs in my SB220 after all
> they were the original tubes. I carefully measured power out. We were going
> to San Diego so on the way I picked up a new pair at RF parts. I got home
> installed the new tubes. Guess what, with new tubes.........exactly same
> power out
>
> Oh, we'll
>
> George, W6GF
>
> Sent from my iPad
>
>> On Aug 10, 2014, at 6:51 PM, "Duane Calvin" <ac5aa1@gmail.com> wrote:
>>
>> Sure, Carter. My Centurion came new with two RF Parts 3-500ZG's. This was
>> fairly early in the life of this tube configuration (graphite anode variety)
>> and manufacturer, and TT had just started advertising they were using them.
>> After about 2 years of occasional use, generally running between 600-900W
>> (and all settings well within the safe zone), one of the original tubes
>> developed the infamous grid/cathode short. I replaced the original tubes
>> with a new matched-pair of 3-500ZG's from RF Parts, and shortly after that I
>> sold the amp (with a used spare tube). I know lots of guys who have had
>> Heath and other amps with EIMAC 3-500Z's in them for years with very few
>> problems. Yes, mine could have been a late early life failure, but at that
>> time I was reading of others having similar problems with these tubes. That
>> was a few years ago - maybe RF Parts has improved their relationship with
>> the factory that makes these tubes and all is well today. So, my "data"
>> consists of one in-person experience along with a number of other reported
>> failures around the same time, for whatever that's worth. The implication,
>> to me, is that the tubes at that time were not of the same quality level as
>> EIMAC's.
>>
>> 73, Duane
>>
>>
>> Duane Calvin, AC5AA
>> Austin, Texas
>> www.ac5aa.com
>>
>>
>>
>>
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Carter
>> Sent: Sunday, August 10, 2014 8:33 PM
>> To: tentec@contesting.com
>> Subject: Re: [TenTec] Hercules 444 amp
>>
>>> On 8/10/2014 2:08 PM, Duane Calvin wrote:
>>> This was certainly true of the EIMAC tubes, as long as you cared well
>>> for them. I've not had as good a luck with the current
>>> Chinese-sourced tubes (specifically, the 3-500ZG's from RF Parts,
>>> which the Centurion uses.)
>>
>> My Centurion (which I obtained used 20 years ago) finally had one of its
>> tubes [rather spectacularly] go to the great beyond.
>>
>> Unless I get really lucky and find a NOS pair at the e-place, it seems
>> like my only other option is a matched pair from RF Parts.
>>
>> Could you please elaborate a bit on your statement above that says "I've
>> not had as good a luck with the current
>> Chinese-sourced tubes (specifically, the 3-500ZG's from RF Parts)".
>>
>> 73,
>> Carter K8VT
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