Ian Iveson wrote:

Phil Allison panicked:

"Ian Iveson Autism ****ed Public Menace "

Eeysore said

Misquote.

No it wasn't.

Do you get *EVERYTHING* wrong ?

Graham

Nick Gorham wrote

Ian Iveson wrote:

Eeyore said

X-ray emission requires a certain *energy level* that has ZERO to
do with
glowing anodes.
So why do x-ray tubes have rotating tungsten anodes?

Ian

They rotate them to allow them to cool.

Aha.

They get hot because the energy in each electron, and the quantity
of electrons hitting them in a unit time. (P=IV)

They emit x-rays if the electrons hit them with sufficient energy to
generate an x-ray photon.

The energy of the electron is dependent on its velocity

The velocity of the electron is dependent on the electrical
potential that has accelerated it.

So if the velocity of the electron is lower than a given value for
the material of the anode, they will get hot, but not emit x-rays.

If the electrical potential is not sufficient to accelerate them to
required velocity, the anode will get hot, but not emit x-rays.

I'll go along with that, more or less.

Current is equally important. And the ability of the anode to lose
heat, and the distribution of temperature also depends on the focusing
of the beam and how well the anode conducts heat.

Since all electrons arrive at the anode with nearly the same energy,
it must be the case that one with just high enough energy to result in
an x-ray doesn't always do so. Presumably the angle of collision with
atoms of the anode has something to do with it too, so you get a
spectrum of emissions from radio to x-ray. Otherwise x-ray tubes
wouldn't need cooling coz they would be making x-rays, not heat.

Nice amp, btw. Nice to see the mad science element of valvecraft on
usenet again.

cheers, Ian

Eeyore wondered:

What's your point ?

My point is to correct your mistake. You said energy level has nothing
to do with glowing anodes. You are wrong about that. Voltage and
current are both important to the rate of energy transferred to the
anode. Electron kinetic energy depends on voltage. So voltage has
something to do with glowing anodes. That is partly why x-ray tubes
need special provision for cooling.

Ian

"" wrote in message
...


Ian Iveson wrote:

Eeyore said

X-ray emission requires a certain *energy level* that has ZERO
to
do with glowing anodes.

So why do x-ray tubes have rotating tungsten anodes?

Why not ?


Graham

Eeyore said

"Eeyore" wrote in message
...


Ian Iveson wrote:

Phil Allison panicked:

"Ian Iveson Autism ****ed Public Menace "

Eeysore said

Misquote.

No it wasn't.

Do you get *EVERYTHING* wrong ?


This is what I wrote:

"Eeyore said

X-ray emission requires a certain *energy level* that has ZERO to
do with
glowing anodes.

So why do x-ray tubes have rotating tungsten anodes?

Ian "

"Ian Iveson TROLLING **** "



** Give this vile scumbag hell & misery.





........ Phil

"Ian Iveson TROLLING **** "


** Give this vile scumbag hell & misery.



........ Phil

"Eeysore"
" Ian Iveson "

What's your point ?


** It has one about a foot long on top of its head.

A genuine "cone head " space alien.






......... Phil

On Aug 7, 10:11 am, Nick Gorham wrote:
Hi,

Given its been a bit quiet on here, I thought I would post some of DIY
output.

Here is a link to some pictures of the GM70 amp that I have been working
on for the past eight months.

http://www.lurcher.org/nick/images/gm70/

Circuit is a C3g Pentode voltage amplifier with VR tube screen
regulator, then 300b driver to 1:1 amorphous interstage to GM70 grid.
Output TX 7k amorphous. Driver and 300b supply, series regulator using
6080, ecl82 and 0d3 (Steve Bench inspired). TJ-Meshplate 300b, running
330v @ 55ma. Copper plate GM70 running 1020v @ 110ma.

All transformers by Automatic Electric Europe.

Rough specs, -3dB points (5w into 8ohm) 18Hz, 52kHz. 3% distortion
reached at 42w into 8 ohm.

It was designed to drive a set of large panel electrostatics, but I have
been using the breadboard version driving a pair of Yamaha NS1000's. My
normal 94dB/W speakers are slightly overpowered for them :-).

I can't take too much pride in them, as their owner did the construction
and I did the design and internal build. But I am still very pleased how
they have come out.

--
Nick

Very nice indeed, Nick. We'll have to drum you out of the club for all
those heresies -- pentodes indeed! series regulators, gee! -- but I'm
sure your amp sounds brilliant precisely because of them.

Andre "Real Men Shunt" Jute (1)
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

....regulate, that is. To join the ultrafidelista, next to every tube
shove up a bigger power tube to shunt its current. For those who were
educated too long ago to remember shunt regulation, and who haven't
"read" anything except Playboy since, shunt regulation consumes half
the power, so the shunt tube must be capable of handling twice the
desired operating current.

Andre Jute wrote:


...regulate, that is. To join the ultrafidelista, next to every tube
shove up a bigger power tube to shunt its current. For those who were
educated too long ago to remember shunt regulation, and who haven't
"read" anything except Playboy since, shunt regulation consumes half
the power, so the shunt tube must be capable of handling twice the
desired operating current.



Yep, shunting is certainly a good solution, howver over the last six
months, I think I can get within 90% of the sound of a shunt with 20% of
the complexity.

--
Nick

Ian Iveson wrote:

Eeyore wondered:

What's your point ?

My point is to correct your mistake. You said energy level has nothing
to do with glowing anodes.

I said nothing of the sort.

I said that a certain *energy level* is required to produce X-rays. The anode
temperature is almost irrelevant. 'Energy level' =/= glowing anodes.

Stop making things up.

Graham