Fusor Forums

Looks like a standard Oven Magnetron used to ionize gas in a Hitachi 308 metal etch system ( semi conductor fab )

Specifications:

* Model No: 12561
* Wave guide length: 21” long
* Round flange: 5 ½” diameter, 6 ¾” total diameter
* Rectangle flange: 6 1/2” x 4 ¼”
* 72.0 hours on Magnetron Fil. Hour Meter
* DT-5 Termination
* Orix AC Fan model no:MB8Z-B3-F25
* Hitachi Magnetron
* ebm: 4.52kVp, Po: 1432W, fo: 2456Mhz, et: 10kVdc

it only costs US $2,205.07

John,

I saw this one on Ebay too, and wandered what the h... it was??

What is it used for?

Steven

In the manufacture of some silicon chips - a layer of metal is put down to protect the device or make connections. This process normally requires the removal of some of the metal to leave a pattern like a printed circuit. To etch to metal off requires a plasma ( at vacuum ) and the magnetron provides the Ionization of the gas.

- What is interesting is that it uses a humble oven magnetron and may stimulate thought in the group.

---- WARNING ---- ---- WARNING ---- ---- WARNING ----

It is simple to remove and use externally, an oven magnetron -- but highly dangerous, as even very small exposure to microwave, at this frequency - WILL - cause cataract in the eyes.

You won't even know - just mild rusty eyes - before you go blind - and it is irreversable.

Not to be experimented with outside proper shielding and wave-guides.

{ Also one of the problems with mobile phones radiating close to the eyes - long term effects not yet known - their use best avoided - just in case }

if anyone knows much about RF sheilding, it would be usefull to have a FAQ on it, magnetrons and the associated PSUs are easy to come by and would be nice to experiment with but questions like 'just how does one stop the RF escaping through a viewport?, down the vacuum plumbing?, up the HV lines?' rather put one off

Oliver

Mesh - you can get KF o-ring holders with mesh inserts, and copper screen over the view ports wouldn't hurt.

Many years ago my dad worked on radar systems for Texas Instruments. He still has a little gizmo from those days to put your mind at ease on such things. It's just a little gray box with a meter, a collapsable antenna, and a fine tuning dial.

I think he called it a field strength meter. At any rate, it measures RF sources, and appears to not really care to much what the source is. We've used it for tuning CB antenna's mostly, but it's original use was testing radar antennas, aparrently some of them were pretty hot stuff and could fry you if weren't carefull. Presumably that little box will also work pretty well for finding microwave leaks.

I'm not going to try it any time soon mind you, but it's a thought.

You can get a microwave leakage detector from just about any firm that sells tools for electronic maintenance and repair. MCM might be a good place to start.

I read a long time ago, that a std NE-2 or NE - 51 neon bulb will indicate the presence of microwave energy at dangerous levels.

If the bulb glows, more than the nominal safe level ( a few mw/cm^2) is present.

A simple plastic wand with a neon bulb in the end will work.

Dave Cooper

A neon with a tiny dipole with one pole going to each leg would enhance the capability to where it would detect at a lower level of radiation. I have seen a superb sniffer made with a 50ua meter movement shunted with a common, standard, 1N21 microwave detector diode and a dipole with ears about 1.5" long attached to each meter lead. This will detect even weak microwave leaks.

Hams do this all the time with the dipole ears trimmed to the frequency they wish to detect, though the length is not all that critical around known stronger sources.