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Re: What is the most powerful vacuum tube ever made?
On 04/08/2018 14:44, Jeff Liebermann wrote:
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I can't find it now, but I saw on youtube someone detecting significant  
amounts of xrays from a vacuum tube at 5kV. I think the problem is that  
most detectors are insensitive to low energy xray photons so people  
think there is no emission, but depending on the glass envelope, there  
might be, it is just hard to detect apart from by waiting for it to  
disrupt your DNA. Below 5kV there are definitely xrays within the vacuum  
tube, the question is whether or not they can get out. I would certainly  
suggest being very careful at even 5kV, and don't trust you xray  
detector to work for low energy xray photons, unless you have a good  
reason to.

Re: What is the most powerful vacuum tube ever made?
Chris Jones wrote:
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Some geiger counters can also make good X-ray detectors:
 https://en.wikipedia.org/wiki/Geiger_counter

I have a couple of those in use, of various types.



Re: What is the most powerful vacuum tube ever made?
On Sun, 5 Aug 2018 16:30:39 +1000, Chris Jones

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The continuous X-ray spectrum looks very much like black-body
radiation. There is a distinct peak, which frequency direct
proportional to frequency (hence inversely proportional to wavelength)
to the electron energy (in keV), while in standard black-body
radiation the wavelength is inversely proportional to temperature.
When viewed on a log-log graph, in both cases the slope is steeper on
the shorter wavelength side and so on. Some physics text books even
suggests that it _is_ the same phenomenon.

At 5 keV, the total X-radiation is more than two orders of magnitude
below that of 25 keV, so not to worry about the radiation at 5 kV
anode voltage.

Up to  about 25 kV, the spectrum looks just like black-body radiation.
At higher voltages, there are discrete spectral lines (depending on
target material), in addition to the black.body continuum.


Re: What is the most powerful vacuum tube ever made?
On 05/08/2018 18:49, snipped-for-privacy@downunder.com wrote:
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Two orders of magnitude is not necessarily a sufficient safety factor.  
In a power amplifier I might well be running two orders of magnitude  
more anode current than a dental xray tube (there goes the "safety  
factor") and with no shielding that could do me a serious lot of damage  
within hours or less. The only options I would consider safe are either  
to calculate how much shielding would be needed and make sure it is  
there in the glass and metalwork, or obtain a detector that is provably  
sensitive to the wavelength of photons that could be present.


Re: What is the most powerful vacuum tube ever made?
On Sun, 5 Aug 2018 23:31:38 +1000, Chris Jones

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The shortest X-ray wavelength possible from 1200 V is 1 nm. The peak
wavelength is slightly longer, definitely only  soft X-ray.

At 25 kV, the minimum  wavelength is 50 pm in the hard X-rays.

I did not find a direct evidence that the X-ray bremsstrahlung (BS)
continuum behaves like black-body (BB)  continuum, but at least in the
BB case, the total energy is proportional to the  forth power. If this
applies also to BS, the total BS at 25 kV would be 160000 times
stronger than at 1200 V.
  
So a 1-2 kV actual anode voltage (not power supply unloaded voltage)
would not be an issue, unless you stick your nose constantly among the
tubes, not recommended :-).  

Getting an electric shock in your nose is quite unpleasant  and may
affect concentration for a day. Done that, not recommended  :-).
  

Re: What is the most powerful vacuum tube ever made?
On 05/08/2018 18:27, snipped-for-privacy@downunder.com wrote:
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Without meaning to state the bleedin' obvious, but energy in > energy out.

The energy of an xray photon is proportional to the accelerated electron  
voltage, which in most instances is proportional to V.

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I have a vision of Jar Jar Binks in my mind after he paralysed his heads!


--  
Mike Perkins
Video Solutions Ltd
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Re: What is the most powerful vacuum tube ever made?
@spam.yahoo.com says...
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significant  
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It should be easy to detect ionising radiation with an electroscope, and  
it is easy to build a cheap one of those.I remember doing it myself as a  
student, but I did have access to fine metal film, though not actually  
gold leaf.

Mike.

Re: What is the most powerful vacuum tube ever made?
Mike Coon wrote:
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I have a few pen type radiation detectors like that,
you charge the (electrometer) by pluggin it in into a unit,
then put the pen in your pocket.
At the end of the day you read the electroscope through a small window with a scale
in the pen to see how much radiation you have been exposed too.
Payed 10 Euro for the set.. Army surplus.
Really nice stuff.
 http://217.120.43.67/nuclear/radiation_pen_IMG_6534.JPG

And that is a raspberry webserver.

Re: What is the most powerful vacuum tube ever made?
On 06/08/2018 04:06, snipped-for-privacy@nospam.org wrote:
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I have one of those, and the full scale is about 1/10th the lethal dose.  
I guess it might be useful in a nuclear war.


Re: What is the most powerful vacuum tube ever made?
Chris Jones wrote:

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Yes, also known as nuclear war detector.
I have a bigger one too, with some ionisation chamber, that runs on a 1.5V D cell.
But these pens are plated with real gold!!!
Could not leave it there.
Then I have real GM counters, and a gamma spectrometer.
And know how to duck under the table in case the bomb goes off.
Nothing to worry about :-)

Re: What is the most powerful vacuum tube ever made?
On 06/08/2018 03:27, Mike Coon wrote:
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Yes, some sort of ion chamber should be ok too and maybe less hassle to  
use. There are some designs on Charles Wenzel's site. But, some youtube  
xray hobbyists use a metal envelope geiger counter that might be very  
insensitive to <20keV photons.



Re: What is the most powerful vacuum tube ever made?
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Here some more pictures,
The set, real gold plating!
the socket top right is where you plug in the pens to charge the electrometer.
 http://217.120.43.67/nuclear/dosi_meter_PP-4127_IMG_3747.GIF

The circuit diagram, glued on the inside, really cool!
 http://217.120.43.67/nuclear/dosi_meter_PP-4127_circuit_diagram_IMG_3737.GIF

The inside, even a spare bulb!
The bulb provides light so you can read the scales in the pen,
reading the pen against daylight works too.
 http://217.120.43.67/nuclear/dosi_meter_meter_PP-4127_measurement_and_reset_unit_IMG_3734.JPG


Re: What is the most powerful vacuum tube ever made?

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The PD500 was a real Xray source though.
A college of mine was repairing a monitor with it and the metal HV cage open.
His face got burned by the radiation.
The glass of those tubes would turn into  a special bluish color over time .
There are you tube movies of someone using those tubes to take X-ray pictures of stuff.


Re: What is the most powerful vacuum tube ever made?

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I found a rather vague reference to such a horn under a history of the
Saturn test (F1 engine).  See Pg 94:
<https://the-eye.eu/public/concen.org/The%20Saturn%20Myth%20Occult%20Symbolism%20Saturn%20Worship/Stages%20to%20Saturn.pdf
(30.8MB)  
   Reverberations of the Saturn tests were quickly felt. The
   acoustical impact was quite evident in the immediate area  
   around the city of Huntsville, and the long-range sound  
   propagation occurred at distances up to 160 kilometers.  
   The result was a rash of accidental damage to windows and  
   wall plaster, followed by a rash of damage claims (some-
   times filed by citizens on days when no tests had been  
   conducted). Aware that climatic conditions caused very  
   pronounced differences in noise levels and long-range  
   sound propagation, engineers began taking meteorological  
   soundings and installed a huge acoustical horn atop a tower  
   in the vicinity of the test area. No ordinary tooter, the  
   horn was over 7.6 meters long and had a huge flared aperture  
   over 4.6 meters high. Its sonorous gawps, bounced off a  
   network of sound recorders, gave acoustical engineers a  
   good idea whether it was safe to fire the big rockets on  
   overcast days.

There are some low quality photographs in the 500 page book, but none
showing a big horn.  However, I did find this photo:
<https://www.al.com/living/index.ssf/2016/12/weird_vintage_alabama_photos_t.html
which seems to fit the aforementioned dimensions and description:
<https://www.al.com/living/index.ssf/2016/12/weird_vintage_alabama_photos_t.html
<
https://image.al.com/home/bama-media/width620/img/living_impact/photo/hayes-horn-1966jpg-490339bdc40cf807.jpg

I would have expected it to be much longer.

In another document, the sound level at the shopping center was
measured at 118dB.  I'm surprised it didn't break windows and ear
drums.  See Pg18:
<http://lcweb2.loc.gov/master/pnp/habshaer/al/al1100/al1196/data/al1196data.pdf
(1.3MB)

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Yep.  Big diesel powered air compressors were what drove such
speakers.  I vaguely recall that some were powered by a diesel train
engine but might be mistaken.  I suspect that the release of all that
pressure would probably have frozen any water in the air and turned it
into a snow blower.  I don't recall any mention of that problem.  Like
a musical horn, the low frequency limit is controlled by the length of
the horn, while the high frequency end is limited by the modulator.
The Huntsville horn was trying in mimic the F1 engine(s), which
according to the history, resonated at 5.25Hz.  That requires are
really long and probably folded horn.  The battlefield horn carries
voice grade audio, where the bottom limit was about 300Hz, and could
therefore be much shorter.  

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I found the photo with an image search using:
<https://www.google.com/search?tbm=isch&q=redstone+arsenal+horn
and the documents by manually groveling through:
<https://www.google.com/search?q=redstone+arsenal+%22horn%22+saturn+5
Note the quotes around "horn" which makes it mandatory to have the
word "horn" in the initial search results.

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--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Re: What is the most powerful vacuum tube ever made?
wrote:



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Here's the audiophile version of the Saturn 5 test horn:
<http://www.mh-audio.nl/Horn/GExpoHorn.asp
Clever design methinks but I don't think I want it in my house.

Trying to see what the 4.6 meter diameter test horn would do, I
plugged these numbers into the calculator;
  Low cutoff frequency = 5Hz
  Throat diameter = 460 cm  (4.6 meters)
  Steps = 25
which resulted in a horn length = 1692.3 cm or 17 meters long.  That's
much longer than the Saturn 5 test horn, which suggests that it wasn't
intended to mimic engine vibrations.  

Interactively plugging numbers for the low end cutoff frequency, I
get:
  low freq cutoff = 7.9 Hz
  horn length = 756 cm
Close enough.  So, the big horn was good for about 8Hz.



--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Re: What is the most powerful vacuum tube ever made?
On Fri, 03 Aug 2018 01:07:29 -0500, snipped-for-privacy@tubes.com wrote:

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Perhaps not the most powerful tube, the RCA 5831 triode has a lot to offer. With
a filament requirement of 6V at 2,220A it can be useful to heat the house as
well. With 10 KV on the plates in a push-pull configuration it can deliver about
370 KW which might be sufficient to impress all audiophiles within a radius of
~10 miles, when fitted with appropriate speakers. Complete details about this
tube: https://frank.pocnet.net/sheets/049/5/5831.pdf

Re: What is the most powerful vacuum tube ever made?
On Friday, August 3, 2018 at 10:34:50 PM UTC-4, Arid ace wrote:
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Here's a 2,158 KW power tetrode
http://www.cpii.com/docs/datasheets/78/8974.pdf

A 7.5MW pulse amplifier

https://www.sokoll-technologies.de/Museum/Auto/Dokumente/Datenblatt_7835-V1_Burle.pdf Datenblatt_7835-V1_Burle.pdf

This should excite the hams. The 1963 RCA Power Tube Catalog  

https://www.kevinchant.com/uploads/7/1/0/8/7108231/1963_rca_power_tubes_guide.pdf



Re: What is the most powerful vacuum tube ever made?
They got you beat -  

https://www.audioasylum.com/cgi/vt.mpl?f=general&m73%8587

Well it's only 2,000 watts per channel more than you wanted, why not ?  

I like how it says it was designed for research into high intensity sound.  

No shit ? Really ? Could it be ? You think ?  

Re: What is the most powerful vacuum tube ever made?
On 08/03/2018 11:53 PM, snipped-for-privacy@gmail.com wrote:
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Here's a homebrew reference design for a 1000 watt monoblock, look at  
that xfmr just look at the mufucka. It probably cost about a grand.

<http://www.chambonino.com/construct/const9.html

OP is talking about building an amp five times that. I can think of  
better ways to throw money away like buying a boat maybe

Re: What is the most powerful vacuum tube ever made?
Largest continuous duty, that's relevant to your application (i.e. not RF)  
is the 8974, 1.5MW plate dissipation.

5kW is rather pedestrian for industrial applications; they're still being  
maintained and sold, probably on the cheap side of things.  Commercial  
applications otherwise (like radiotransmitters) are basically all solid  
state now, for good reason.

Tim

--  
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
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