Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: DummyLoad on March 30, 2011, 11:12:18 pm
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i've read about them. a local ham and occasional tube supplier of mine sold me 4 at a price i couldn't refuse. they appear to be new. i was wondering with all the radiation from dying nuke plants and the economy failing again b/c of oil supplies, if i shouldn't go ahead and build hardened guitar amp...
ya gotta admit they just oooze heavy duty. and, they are handsome as far as tubes go.
(http://i2.photobucket.com/albums/y11/pmitchel/SilverStoned-Champ/2011-03-30_20-21-59_66.jpg)
(http://i2.photobucket.com/albums/y11/pmitchel/SilverStoned-Champ/2011-03-30_20-23-33_161.jpg)
(http://i2.photobucket.com/albums/y11/pmitchel/SilverStoned-Champ/2011-03-30_20-23-49_94.jpg)
now what to build... their characteristics seem similar to 6L6's, perhaps a SE pairs?
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Max altitude = 80,000 feet
Max Impact shock = 500G
Bendix was designing tubes to be handled by Fred X way back when.
http://www.mif.pg.gda.pl/homepages/frank/sheets/131/6/6384.pdf
That's a cool data sheet.
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too cool!
Defiantly from the days of we build things to last!.
Page 3 of the link Butters gave mentions suitability for use in "servo discriminator circuits"
Seems I remember that line from Dr. Strangelove
or maybe it was something like "switch over the circuits to the CRM discriminator."
Either way I still look at something like that built for a B-52 and as fate has it it's winding up 50 odd years later in some kooky amp! :icon_biggrin:
Seems fitting it should be destined to make HARD rock :l2:
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Seems fitting it should be destined to make HARD rock laugh
yes, yes it do... indeed. :icon_biggrin:
now what to build with them? SE? P-P? hardened pre-amp tubes?
:help:
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That shure looks like a tough tube they were made for rock :worthy1:
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So JAN (Joint Army Navy) tubes were for the American military, right? How on earth are there JAN tubes made by Sovtek? This is truly a strange world we live in.
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I think the KT88 you see is just fore a scale to compare the sizes
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I think the KT88 you see is just fore a scale to compare the sizes
ayup. :wink:
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So dummyload is that like a 6l6 tube on steroids.
Thanks Bill
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Look at how thick the spacers are in that tube.
Brad :icon_biggrin:
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So dummyload is that like a 6l6 tube on steroids.
Thanks Bill
not exactly on steroids... about the same slope as 6L6, maybe a bit less steep. from my limited knowledge it seems as though one could use very close bias parms to the 6L6 and the differences would likely be nothing to write home about.
purportedly it's a ultra-high reliability tube that was used in radar sets as the sweep driver. i was told that they were mostly used in USAAF intercontinental bomber radar sets up until the mid-late 70's. i cannot validate that information.
i do have reservations about running them in SE service since they are a rare tube and would probably fare best in a P-P design @ 70% Pdiss, rather than the usual 90% Pdiss for SE. i know, i don't have to run them @ 90% in SE, but it seems to me it would be moot to do otherwise.
--DL
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i do have reservations about running them in SE service ...
You've seen tube with a top cap for the plate or grid, right? Call those "double-ended" tubes.
What I gathered was meant by "single-ended tube" on the data sheet was a reference to the fact that all connections to the elements were brought out to 1 side of the tube; hence, "single-ended."
Yeah, I'd look at this tube as a 6L6-type with a hungry heater. I notice the 6AR6 it is based on is rated similarly to a 6L6, including the eventual creep-up in plate dissipation.
I thought for a split-second we might have a cool replacement for 6L6's, but I saw that AES wants about $24 for the 6AR6 types and $60 for the 6384's. Yeooow! Then again, tube prices seem to be going up. British KT66's are around $200. Maybe I need to sell my EL37's and finance a project. :laugh: