I have a 3CX1200Z7 tube, that has a 6.3 vac fil. Has three pins for fil &
cathode and a grid ring around the middle to ground the grid. Any tube has
to go thru a gettering process before putting B+ or RF to the tube. Google:
How to Getter a vacuum tube. Willy K3VW
Sent: 5/14/2010 3:00:17 P.M. Eastern Daylight Time
Subj: Amps Digest, Vol 89, Issue 22
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1. Hombrew 3-1000Z in SA (Patrick Barthelow)
2. air director (Herzog)
Date: Thu, 13 May 2010 16:36:29 -0700
From: Patrick Barthelow <firstname.lastname@example.org>
Subject: [Amps] Hombrew 3-1000Z in SA
Content-Type: text/plain; charset="iso-8859-1"
As most of you have read, I am seeking an amp for a friend in Uruguay, via
almost any mechanism that is minimal cost. Basket cases, tubes, parts,
Come to the conclusion that most has to be found, or originate in country,
due to very stiff duties (apparently ~100% of new paid value) paid, or
shipping costs for heavy items.
I wonder if duties can be waived or reduced if bring in is accompanied,
with a strong letter of endorsement by the national Amateur Radio Body,
explaining the emergency comms, public service aspects of amateur radio. with
reference to the specific person receiving the item?
I found a single 3-1000Z nicely built amp with separate power supply, now
for sale by family of an SK ham in Uruguay.
Has not been powered up for at least 2 years, when the SK ham passed away.
I love the big bottles, but dont know any specific gotchas on the
3-1000Z. So, looking for exprienced feedback on the 3-1000Z. :
1. Are 3-1000Zs prone to failure due to gas intrusion through the
glass/metal seals, with dormancy/non use, like the 3-500Z?
2. Can an old stored 3-1000Z be rejuvinated in the usual way, burn in, low
B+ gradual increase, getting the plate hot?
3. What is the availability of replacement 3-1000Zs New or used?
4. If this is the last practicaly obtainable 3-1000Z in the country,
what modern external anode triode might be a electrically similar tube, using
similar B+ and having similar Plate Z in amateur operation, that could be
swapped (with rebuild, redesign of the tube mount, and fil transfomer
change) into the amp if this 3-1000Z fails? (maybe the GS-35B?)
5. Is it a good idea to design a filament cold start circuit, or perhaps a
small variac to bring the filament voltage on to try to get maximum years
out of the tube?
I think I remember a 7.5 V 21 Amp fil requirement. Pretty good THUNK!
when you turn on filaments, I bet.
6. Can 100 watts input drive them to Legal Limit? With a tuned input?
Without a tuned input?
7. What is the input Z if direct fed, without a tuned input circuit?
Thanks for all your prior valuable input.
73, de Pat Barthelow AA6EG
Hotmail has tools for the New Busy. Search, chat and e-mail from your
Date: Thu, 13 May 2010 19:48:53 -0400
From: Herzog <email@example.com>
Subject: [Amps] air director
To: Ham-amps <firstname.lastname@example.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Somebody wanted this, My computer lost messages as mail program updated.
I got the box, but no address to send it to.
Eimac's "epoxy-like" cone that puts air from chassis/tube socket to tube
like 4CX10000. Anyone want? K2LB. 585-482-6151 or e-mail.
Ps, it is 7-3/4 inch tube, 8.5 inch diameter at bottom, and 9 inch bolt
circle for the 4 mounts.
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