Spectra of tube glow: any data?

[Wavebourn]

Hi fellow DIYers;

it is not the first thread about tube glow. I have an idea, to use a spectroscope to find out what glows inside of tubes. Different spectral lines may give a clue what kind of metals or gases produce the glow.

Is it a good idea, or wrong? Did anybody try it before?

Here is description of the device I found in the net, may it be usable?

A CD spectrometer

It is made of a cereal box and peace of CD.

[The Space Egg Corp]

Originally Posted by Wavebourn

Hi fellow DIYers;

it is not the first thread about tube glow. I have an idea, to use a spectroscope to find out what glows inside of tubes. Different spectral lines may give a clue what kind of metals or gases produce the glow.

Is it a good idea, or wrong? Did anybody try it before?

Here is description of the device I found in the net, may it be usable?

A CD spectrometer

It is made of a cereal box and peace of CD.

Hi Wavebourn

The Space Egg Corp likes diy test equipment like that.
Put's all these new flatscreen scopes and DSP eq's & mics to shame !
All one needs is ears & an apetite for cereal !

I used to run endless optical filters on 50K's worth of Perkin-Elmer test gear, which was constantly going back for 5K recals.
Now if we had eaten more cereal.....

I'm gonna make one dude, I'm just finishing a box of 'Pecan Crunch' & have a bad CD burn under a large scotch on my desk.
Brilliant, finish scotch, 5 mins later.....finished test equipment.

My EL84's glow BLUE, which some seem to report and others not ?
It remind's me of special effects on the 50s' Sci-Fi 'Forbiden Planet' before Leslie Neilson did comedy.

Cheers

Simon

P.S. Have subscribed

[kevinkr]

One of my favorite movies..

On topic I think the idea is intriguing, wondering whether there is anything close to sufficient resolution? You'd also have to heat the tube up a lot I think to get spectral lines of anything other than the gas and filament. (to incandescence?)

SY probably has some answers to this I'd suspect.. Calling SY

Something tells me the spectral lines may be too close together and faint to distinguish them with commonly available household materials, and inexpensive digital imaging hardware. (a digicam.. )..

[The Space Egg Corp]

Originally Posted by kevinkr

One of my favorite movies..

On topic I think the idea is intriguing, wondering whether there is anything close to sufficient resolution? You'd also have to heat the tube up a lot I think to get spectral lines of anything other than the gas and filament. (to incandescence?)

SY probably has some answers to this I'd suspect.. Calling SY

Something tells me the spectral lines may be too close together and faint to distinguish them with commonly available household materials, and inexpensive digital imaging hardware. (a digicam.. )..

My FAVORITE movie...

Leslie Nielson proves top results are available on a low budget..!

My EL84's are glowing a bright MID-BLUE, a kind of Picasso 'blue period' cirilian blue (sorry no pun intended, Typo:- blue colour).
My EL84's run at nuclear temperatures (best sound IMO) no extra heat required.

Cheers

Simon

[The Space Egg Corp]

A further thought would be...

A very thin slot formed with very thin, say, 2 cut pieces of alu. foil would I think give optimum results.

Or perhaps a marker-pened over piece of glass, with blackening scored off with a blade.

Cheers

Simon

[smoking-amp]

gaseous glow?
Umm... is this drilling holes in tubes thing getting out of control here? Maybe you need to shine a high power laser thru the tube to excite the gases, vaporize the barium getter. Nuke-it in the microwave....

I remember seeing some experiment writeup once where a tube or lightbulb was immersed in some chemically reactive solution, probably hot, and a high voltage applied between the solution and the inner elements. Ions from solution where induced to electro-migrate thru the glass (probably after a few days at least) by electrostatic charge buildup on the inside of the glass, and become trace gaseous impurities in the bulb. Then some spectra could be seen in a HV discharge within the bulb.

[Ty_Bower]

Originally Posted by The Space Egg Corp

My EL84's run at nuclear temperatures (best sound IMO) no extra heat required.

Four hundred volts from plate to cathode, thirty milliamps baby. Fixed bias, ultra-linear, all the way. Military Russkies glow nice and blue all over, civilian tubes need not apply.

[smoking-amp]

Now imagine a tube amp operating for years in a smokers environment. Electromigration of @%$#*+! thru the bulb, integrated over years. Probably affect the sound of the tube as well as the gaseous spectra. Better make sure those NOS tubes weren't stored for eons in some pipe or cigar smokers warehouse! And heaven forbid if some mouse or rat pee-d on the tube boxes in storage.

[The Space Egg Corp]

Originally Posted by Ty_Bower

Four hundred volts from plate to cathode, thirty milliamps baby. Fixed bias, ultra-linear, all the way. Military Russkies glow nice and blue all over, civilian tubes need not apply.

SV83 Baby !!!!

Havanas only smoked here (& an ocasional blunt).

Simon

[The Space Egg Corp]

Originally Posted by Ty_Bower

Four hundred volts from plate to cathode, thirty milliamps baby. Fixed bias, ultra-linear, all the way. Military Russkies glow nice and blue all over, civilian tubes need not apply.

Hi Ty Bower

Are you sure that's not Tyler Durden ?
Project Mayhem ring a bell ?
Your not trying to blow that amp of yours up, are you ?

Cheers

Simon