Plasmatweeter

[joe carrow]

George,

Thank you for sharing this interesting project with us!

[Audio_idiot]

Hi George,

Thank for the very detail reply.

But I'm still too stupid to know it all...

More questions,
I meant the curve plate visible from the fromt of the tile, is this the one you refer as Reflector? Any special requirement on the curevature?

What is the frequency range of your tweeters?

I think I should start with a stainless steel electrode on a household fuse holder similar to you 117db tweeter. No welding required...


Thousand Thanks

KenC

[George Green]

Hi Joe!
Yes, very interesting, You should hear only once as sound.

Dear KenC,
before I you an answer give now go times first on these sides:

http://www.forumromanum.de/member/fo...h=1&threadid=2

that is everything in German, but you will see much. You should not too much spend operate,
go everything completely simply. You should find procurement problems have we solutions.
Greeting, George

[-(daz84)-]

Hello George very interesting tweeter!I really wish i had the skill to make one.May i ask where you got the mesh from in your very first picture of the tweeter?Also does the mesh have a name?I am after some for protection on my ribbon tweeters.

[George Green]

Hello daz84,
thank You for interest,
this mesh is of an old ELA-loudspeaker, sorry.
It is also not usefull for tweeters cause it has a too big surface.

With you it gives nevertheless probably also ikea?
There the straight such garbage pails with very useful material for 2.99¤ have.
The material costs 20¤ with us in the shop approx.


George

[Audio_idiot]

Hi George,

Thanks for the link.

Will study the link closely.




Cheers

Ken

[bear]

George,

Interesting plasma tweeter.

A few questions. I did not find the answers in your text.

The "silver"? Is that the starter electrode?
The two electrodes for the plasma arc, those are tungsten??

The arc seems relatively large and hot for a typical plasma tweeter, does it have significant "self noise" (hiss)??

Also, you can only run the unit for a short time now, because of overheating of the output tube??

Have you checked your AM or FM radio for RF noise/interference??

Thanks.

_-_-bear

[George Green]

Dear bear,
from silver the above electrode is , silver (AG) oxidized not and therefore gives it no noise.
The starter-elektrode is an iron-nail.
The lower electrode is from tungsten. You see on the page 2 the upper pictures, there come no more music,
that are wound up and also begin the tube perfectly to glowing. With the normal enterprise to for instance 110db
the tube does not glow! Only with full volume it glows a litte Time later (10-15 sec.). Therefore also the
strong inverse feedback of the screen grid. Thus the delimitation works reliably. The Tweeter does not
have noises or hissing, it is perfectly quiet. Disturbances in the radio (30-35 MHz) are only in the room
ascertainable exactly the same as with Magnat mp-02 those my friend have. My Stereo-Anlage and the television
run without disturbances. The devices, I have two, run approx. 18 hours daily.
Many greetings, George

This pic shows the tweeter from above.
This is the main-part, the rest is only work. This is art.

[bear]

George,

so the upper electrode is silver?

why not tungsten?

IF tungsten then what happens to the sound level??

How often does the silver need to be replaced? Not at all?

IF the silver does not melt or ablate (get burned up or melted), then why does the copper?? Or why does not the silver??

What frequency does ur tube oscillate at??
The usual 27mHz range??

_-_-bear

[George Green]

Hello bear,
the upper electrode is silver cause with tries out i found out that that does not glow oxidation arrears and katalytproducts produced if it then.
The sound-level is still the same. This only the exactly distance to the Backside needs.
Therefore the music remains clear, clean the sound. It does not wear itself out. Silver leads the warmth better
still than copper and leads waste heat faster, copper oxidized fast.
30 - 35 MHz, depending upon temperature and naturally the number of turns.
27,12 MHz is the permitted frequency thereby no disturbances in the radio come. It is to be worked not
necessarily so exactly, then one must work with an oscillator and quartz. On it I work straight,
but that becomes not simple and is not necessary also. many greetings George