I sure hope so, they are a very unstable tube as replacements in many amps
without some rework and especially neutralization. I wound up using them for
AM modulators or replacing 811A's at lower voltages.
Carl
KM1H
----- Original Message -----
From: "Al Kozakiewicz" <akozak@hourglass.com>
To: <amps@contesting.com>
Sent: Wednesday, January 19, 2011 6:01 PM
Subject: Re: [Amps] 572Bs
>I thought the Svetlana tubes were long out of production?
>
> Al
> AB2ZY
>
> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
> Behalf Of Alek Petkovic
> Sent: Wednesday, January 19, 2011 5:58 PM
> To: amps@contesting.com
> Subject: Re: [Amps] 572Bs
>
> My pleasure Mitch
>
> I get mine from a supplier in China but you can get them from the guy
> below at exactly the same prices. I have bought from him also and I
> believe that Carl, KM1H has dealt with him on numerous occasions.
>
> http://stores.ebay.com/qMall/Tube-/_i.html?_fsub=7152201&_sid=214893880&_trksid=p4634.c0.m322
>
> 73, Alek
> VK6APK
>
>
> At 06:48 AM 20/01/2011, Mitch Cox wrote:
>>I have no way of knowing where the Chinese tubes I have experienced
>>have come from. The brands that I have tried would include; Taylor, RF
>>Parts select, Penta (X dealer), Jet Stream and the no name white box
>>variety. I cannot recommend any of these to anyone for any reason. The
>>quality control on the afore mentioned that I have purchased were
>>terrible, never 2 the same length, had alignment problems with the grid
>>and filament structures, lost the anode caps, were not glued to the
>>base correctly and the ones that didn't flash over immediately or did
>>actually light up and work, didn't last 6 months. If you can tell me
>>what brand name they are selling in the US under I would be more than
>>happy to purchase them and gladly give them a try. If in fact they are
>>marketed under a brand I have already mentioned don't bother because
>>myself and thousands of other US hams have had or are experiencing the
>>same problems with these products daily. Ameritron has piles of them
>>that have been returned.
>>Best Regards,
>>Mitch
>>W4COX
>>----- Original Message -----
>>From: <mailto:vk6apk@bigpond.com>Alek Petkovic
>>To: <mailto:amps@contesting.com>amps@contesting.com
>>Sent: Wednesday, January 19, 2011 5:21 PM
>>Subject: Re: [Amps] 572Bs
>>
>>That's certainly different to my experience Mitch.
>>
>>The 200+, Shuguang (Chinese) 572B, that I have bought direct from China
>>and onsold to hams in VK have been absolutely superb.
>>
>>I have had just 2 failures "out of the box" and none after that in the
>>7 years that I have been handling them. I have had zero failures of any
>>kind from a similar number of 811A tubes from the same factory.
>>
>>The 2 failed 572B's were replaced without question on my subsequent
>>order from the supplier in China.
>>
>>Not only are they superb in that regard, they are plug and play with
>>the Cetron variety and they really produce the grunt when needed and
>>their longevity is excellent when care is taken with filament voltage.
>>
>>I can't say anything other than I am really impressed with them.
>>
>>
>>73, Alek
>>VK6APK
>>
>>At 11:27 PM 19/01/2011, Mitch Cox wrote:
>> >Paul,
>> >I am sure you will receive many answers to your question on this
>> >subject. I will give you an answer that pertains to my experience
>> with 572B's.
>> >I have built many amplifiers over the years for people using this
>> >tube, only 3 last year and one so far this year. In my experience the
>> >Russian tube is by far superior to what is available from the Chinese
>> >today regardless of the name or label printed on them. In the past 10
>> >years I have found that the Chinese tubes have about a 40% failure
>> >rate new, out of the box here. So far I have had one Svetlana tube
>> >fail to light out of about 50 that has been through my shop. The
>> >Svetlana tubes last much longer and have much higher stage gain than
>> >any of the Chinese tubes that I have tried. I have had very good luck
>> >purchasing these tubes from Frank Krize, K5SVC at Krize Electronics.
>> >I am pretty sure that my experience is not an exception but keep in
>> >mind that a fellow asked a simple question about a fuse about 5 weeks
>> >ago and that lasted at least 3 weeks on this forum venturing from a
>> >simple fuse question blossoming into fluid induction breakers. There
>> >are a lot of people who don't co
>> > nsider the 572B a worthwhile venture but for $150.00 for 3, they
>> >pretty much equal the performance of a 3-500Z.
>> >Best Regards,
>> >Mitch
>> >W4COX
>> > ----- Original Message -----
>> > From: Paul Manuel
>> > To: <mailto:amps@contesting.com>amps@contesting.com
>> > Sent: Wednesday, January 19, 2011 8:11 AM
>> > Subject: [Amps] 572Bs
>> >
>> >
>> >
>> > Good morning. I'm a new list member and I've really learned a lot
>> > from the archives. The knowledge is much appreciated.
>> >
>> > Now a couple of questions...where do most of you buy quality 572Bs
>> > at a reasonable price? What is the final concensus on Chinese vs
>> > Russian tubes? Thanks!
>> >
>> > 73, Paul K4PDM
>> >
>> >
>> >
>> > _______________________________________________
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