Penta Tubes//3CX800A7

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W5INC
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Joined: Sun Dec 04, 2005 8:08 pm

Penta Tubes//3CX800A7

Post by W5INC » Fri Nov 07, 2008 9:48 pm

I just got a couple Alpha 87As with no tubes in the amps. I have been looking for some 3CX800A7s and ran across some Penta tubes. Seems like Svetlana doesn't produce tubes anymore and Eimacs are running about $650.00 a piece. Has anybody here on the board used Penta tubes in their amps? I have never heard of Penta and would like some more information on them if anybody knows of them. TIA, 73s DE W5INC

WA9WVX
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Penta Labs Vacuum Tubes

Post by WA9WVX » Sat Nov 08, 2008 4:20 am

Hello Mike,

Penta Labs was incorporate as a quality RF vacuum tube manufactrure half way through the 20th century in 1951. They are well known by the Amateur Radio Community and Radio & Television Broadcast Stations. In the early ARRL Handbooks, you could find their full page product advertisements in the rear of these books. I see that Raytheon Corporation purchased Penta Labs in 1973 and probably built many Department Of Defense JAN* RF Vacuum Tubes for our military's transmitters. I wouldn't hesitate using a Penta Lab RF Product in my VHF KW with their reputation.

Here's the Penta Labs website link:

http://www.pentalabs.com/

In regards to Svetlana Vacuum Tubes or SED still exists and you can find their Products at this distributors website:

http://www.rfparts.com/tubesvet.html

For an alternative Svetlana RF Vacuum Tubes source try QRO - Parts com at the following website link:

[url]http://qro-parts.com/

NOTE* JAN represents the Joint Army Navy DOD Electronic Development Contracts

73,

Dan
WA9WVX

W5INC
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Joined: Sun Dec 04, 2005 8:08 pm

Post by W5INC » Sat Nov 08, 2008 3:12 pm

TNX Dan for the help. I went to the Penta web site and it was very informative. I even got a re-fresher course there on how tubes are made by Penta. When talking to Penta it seems they have a run of 3CX800A7s every couple of months. Their run consists of about 400 tubes made up for that run. Penta was very adament about that almost all of the tubes from their next run in 4 weeks are allready spoken for. Penta wants your credit card information so that when the tubes are made they will then charge your card and then send you the tubes. I have no problem with that but the 3CX800A7s must be a very popular tube in MRIs and other related fields for a run of 400 tubes to be snapped up that quickly. At $250.00 less a tube then Eimacs it may be the reason why. Looking forward to see if anyone else has any information on these Penta tubes, TIA DE W5INC

WA9WVX
Posts: 103
Joined: Tue Aug 09, 2005 2:31 am
Location: QRZ Indicates Northern Illinois

Penta Labs RF Tubes

Post by WA9WVX » Sat Nov 08, 2008 9:29 pm

Hi Mike,

After reading your reply regarding Penta Labs RF Tubes especially your concerns about "their 400 piece build" I began to wonder what was happening at that OEM supplier. Four hundred pieces of anything from major manufacturing facility is practically nothing. They would be able to build that quantity in a week or two as the 3CX800A7 RF vacuum tubes are a well established product.

So back to the Internet I went but this time I searched for the Svetlana SED website and who were their U.S. Distributors? I hope you're sitting down for the following information. In fact here's the Svetlana SED website link:

http://www.sed-usa.com/index.asp?strTyp ... stributors

I can honestly tell you that I almost fell off of my chair when read that Penta Labs is a Distributor for the Svetlana SED Product Line! Perhaps it shouldn't have surprised me that much considering the way Corporate America's Management Think or Lack of Long Term Thinking what will drive down all of our manufacturing facilities and career positions from the mandate to Outsource and build products outside the United States of America which I personally do not agree with.

73,

Dan
WA9WVX

W5INC
Posts: 30
Joined: Sun Dec 04, 2005 8:08 pm

Post by W5INC » Mon Nov 10, 2008 7:42 pm

Well Dan looked around and found this review of the Penta tubes. Maybe it's a good thing they don't make lots of tubes. After reading this review it will make me buy some other kind of tube, see what you think, Mike

http://www.eham.net/reviews/detail/7277

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