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| Reviews Summary for Cetron Jan 811A |
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Reviews: 8
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Average rating: 3.2/5
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MSRP: $$25
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Description: Would like to give positive review of Cetron Jan 811A.
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Product is in production.
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More info: http://
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write your own review of the Cetron Jan 811A.
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AA2SM
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Rating: 0/5
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Dec 27, 2010 09:21
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A Waste
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Time owned: 0 to 3 months
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My Ameritron 811 Amp is three years old an really enjoyed it. My original taylor tubes lasted over a year and kept one good tube from the original aside. Replaced with another set of Taylors. Ran great until about 2 weeks ago. Saw that one tube was dark so decided to order the Cetrons 811. Wow my amp went bizerk. Could not tune it up. SWRs all over the place. Finally I got 350 watts out and that didn't last long. Amplifier got real hot. I admit Ilm not the smartest fish in the ocean but when I combined the one good taylor tube from my original set with the two from my second , my amp ran great. 600 watts out easy and ran cool. Im packing my cetrons up for the garbage.
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XMWUF
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Rating: 4/5
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Nov 28, 2010 01:30
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Great buy!
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Time owned: 0 to 3 months
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These tubes came with 1988 date code. Worked very well so far. Caps were intact on delivery. Power out measured easily as well as the 5 year old Ameritron tubes that came with the 811H. Thanks Nebraska Surplus!!
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W6WUH
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Rating: 4/5
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May 27, 2010 18:11
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Gm 900 RCA Gm1300 +
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Time owned: more than 12 months
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I don't think there is any question that the american made Cetrons are superior to any of the chinese made tubes.
However, I did measure the transconductance of a pair of NIB Cetron Jan 811-A tubes and found them to both measure 900. New RCA Jan's will measure about 1350.
In linear amplifier service this probably won't matter. Most vacuum tubes that test 80% of new work exactly like new ones, so long as they have 100% filament emission !
What will matter is the quality of the filament contruction... the getter, and coating on the plate. Thorium and the other rare earth metals and the vacuum equipment and HV testing are also critical.
The American tubes are surely going to excell in this department ! No cigarette butts found in a Cetron that I have heard about !
Why not use some permanent high temp locktite,
or even super glue on your plate caps before you install them ? Glass to metal contact area.
It isn't hard to re-solder plate caps, if you don't break the envelope !
Surplus sales claims to have several thousand of 811-As.. with discount for qty. Get some.
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K1DT
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Rating: 4/5
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Oct 8, 2008 09:14
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Fine Tube - But Handle w/Care!
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Time owned: 0 to 3 months
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Nice tubes at a nice price from the nice people in Nebraska. These are USA made, NOS 1988 date code, RCA/JAN type construction. They work very well. BUT - be Very Careful with the Plate Cap! The plate cap cement has dried out and failed, likely NG right from the factory. Even knowing this problem (there is also a warning on the invoice) and using utmost care, I cracked the seal on one by simply pushing on the plate connector, the only tube I have ever broken in 40 years. My advice: for this good price buy an extra tube and be EXTRA Careful. Some add a bead of JB Weld epoxy (500 deg F rating) around the plate cap but I have not tried that. And don't spend any extra for "Matched Sets", in my opinion this is total nonsense unless you are using the tubes in a fixed bias push-pull audio amp. 73, Tess - K1DT
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K3VYY
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Rating: 5/5
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Jan 31, 2008 11:38
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Great!
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Time owned: 0 to 3 months
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I recently found the Chinese "P" 811's in my had a couple with the bulb separated from the base. I purchased a matched quad of the Cetron 811A's from Surplus Sales of Nebraska, and WHAT A DIFFERENCE. More power output, and they seem to load better. Very Happy.
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K8DXX
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Rating: 0/5
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Feb 3, 2001 19:13
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OLD JUNK
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Time owned: more than 12 months
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In my previous review, I reported having problems with the glue and seals on JAN Cetron 811As purchased for my Ameritron amp. First set was useless but the second set seemed OK. Well... yesterday I opened up my AL 811H to replace those Cetrons with Taylor 572Bs (no more power expected, just greater durability). Anyway, the anode caps on 2 of the 4 were already detached and hanging over to one side. Of the four tubes, I could remove only 1 without them loosing their caps and seals.
I talked to some guys on 3865 and 3875 last night. Several reported having similar problems, probably because these tubes sold by Surplus Sales of Nebraska are just that, "surplus," from which war I don't know. We suspect that the glue dries out with age.
I also emailed Surplus Sales... and asked for an "adjustment" or a partial credit toward purchase of more 572Bs. My request was refused; "no adjustment is possible." I do understand that the tubes were almost 2 years old. Funny thing though, my otiginal set of Chinese 811As are fully intact and easily endure the rigors of an install/deinstall. They also still produce nearly full output.
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K8DXX
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Rating: 4/5
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Jan 26, 2001 00:31
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First set defective
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Time owned: more than 12 months
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My AL811H came with Pride (Chinese) tubes. They worked fine but always made a strange noise when lit. So, after three years, I purchased a matched quad from Surplus Sales of Nebraska. 3 of the 4 tubes had faulty seals or glue jobs on the anode cap because they broke off during installation. The vendor quickly replaced them. Since then, they have worked fine.
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N8FVJ
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Rating: 5/5
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Dec 22, 2000 21:22
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Excellent Product
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Time owned: 0 to 3 months
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Tested four new Cetron Jan 811A tubes in an Ameritron AL811H amplifier. These tubes were compared to a new set of now discontinued Svetlana 811A tubes. The Cetron 811As produced about 25 watts higher output over the excellent Svetlana tubes. Tuning the AL811H was exactly the same and the input SWR did not change. The Cetron has the 'U' shaped ribs on both sides of the plate just like the older RCA 811A. Highly recommended!
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