"Fun to think about", Roger! It has also opened the door for
some pretty good humor; "Fire up the linear", for example, HI!
I, too, have a problem with the high cost of power tubes, and
this is why I started gathering information on the "surplus"
Russian transmitting tubes. As examples (and I'm NOT selling
tubes - merely telling you what I pay for 'em delivered to San
Antonio, TX!), NOS 4CX800's (GU-74B) for $70 each delivered,
NOS 1500W plate dissipation "coaxial" triodes (GS-35B) good to
1000MHz for $100 each delivered, NOS 4CX1600 "equivalent" (GS-23B)
for $160 delivered, NOS 350W dissipation triodes (GI-7B) good
for multi-tube PAs through 70cm (2 tubes, >800W output) for $30
each delivered. If you're paying more, you're paying too much!
AND there are other types of tubes, too, like a 200W dissipation
tetrode (GS-15) tested at 280W (thermally stable!!!) output on
23cm (formal design under development), NOS for $25-30 delivered!!
Data on PAs using most of these tubes (and some others) can be
found at http://www.nd2x.net/ (select "QRO"). Some PAs only
have pictures, a few PAs are built for sale, and there are several
PAs which could be built from the information provided by HAMs
from around the world.
Now, if I only had time to build them all myself - HI!!
>--- Original Message ---
>From: "Phil (VA3UX)" <phil@vaxxine.com>
>To: Jeff Stai WK6I <jstai@home.com>
To: <amps@contesting.com>
>Date: 7/5/01 2:39:57 PM
>
>
>At 10:23 AM 7/5/2001 -0700, Jeff Stai WK6I wrote:
>
>>At 10:08 AM 7/5/01, Phil (VA3UX) wrote:
>> >>With the high price of tubes, I wonder if anyone has ever
invisioned a
>> homebrew project to actually make the tube from scratch?
I know that it
>> would be a little more than the average ham is used to working
with but
>> why could we not use something such as stainless steel tubing
and come up
>> with a decent power transmitting tube. After all, someone
once did that!
>> >
>> >Virtually impractical to do in a home setting Billy. Not
impossible, but
>> largely impractical. The cleaniness requirements are high
and the
>> equipment needed to produce a hard vacuum is expensive. And
then there's
>> the unique materials required, etc, etc.
>>
>>hi - It is worth noting, however, that the first tubes were
in fact "home
>>brew"...
>
>No question - with a glass blower and related equipment, oil
bath vacuum
>pumps. And they weren't very good by today's standards, but
they did quite
>well with what they had.
>
>Remember, the point of the original post was circumventing the
high cost of
>tubes possibly via homebrew. Tubes can be home-brewed - but
not at a lower
>cost than production jobbies. It's fun to think about though.
>
>Phil
>
>
>>It would be something you would do because you want to, not
because it
>>would save money, etc.
>>After enough practice and investment (time, materials, equipment)
a
>>usuable product
>>could be the result!
>>
>>GL - jeff wk6i
>>
>>
>>jeff stai
>>radio stuff: WK6I in DM13
>>rocket stuff: NAR #21059 TRA #3356 Level 2 Cert.
>>email: jstai@home.com or wk6i@arrl.net
>>ROC web page: http://www.rocstock.org/
>>LDRS web page: http://www.ldrs20.org/
>>
>>
>>--
>>FAQ on WWW: http://www.contesting.com/FAQ/amps
>>Submissions: amps@contesting.com
>>Administrative requests: amps-REQUEST@contesting.com
>>Problems: owner-amps@contesting.com
>
>
>
>--
>FAQ on WWW: http://www.contesting.com/FAQ/amps
>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
>
>
--
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