"Anchor" wrote in message
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Any suggestions on how to build a 2.4 GHz CW transmitter with a microwave
oven magnetron and a 2.4 GHz "pringle" or coffee can style antenna?

There are tons of "pringle" or coffee can antennas or similar on the web.
For example: http://flakey.info/antenna/waveguide or
http://www.turnpoint.net/wireless/an...coffeecan.html

I suppose one need only insert the magnetron antenna into the coffee can
where one would normally mount the N-connector feed point.

A labeled diagram of a microwave magnetron can be found at:
http://www.gallawa.com/microtech/mag_test.html

I suppose the metal coffee can has superior micro shielding properties
relative to the aluminumized cardboard pringle can.

Would I be better off with plumbing copper drain pipe from the stray RF
exposure perspective?

Since microwave magnetron use a half wave power supply, can I use two
magnetrons in the same coffee can powered from a single AC HV transformer
with a pair of HV rectifiers to feed alternate cycles to the magnetrons?

Greg, VE0ACR

I once looked at a microwave oven on a spectrum analyzer (Loosely coupled
near the door seal). The signal was spread over 100s of MHz. It also
appeared to be pulsed. The spectrum, however, did not look like the
expected
Sa(x) distribution. Magnetrons are not noted for their stability, and are
probably not suitable for CW. I have played with tunable 500 mW klystrons,
and they can drift 10s of MHz (at 12 GHz), in a very short period of time.

73,

Frank

Frank wrote:

snip


I once looked at a microwave oven on a spectrum analyzer (Loosely coupled
near the door seal). The signal was spread over 100s of MHz. It also
appeared to be pulsed. The spectrum, however, did not look like the
expected
Sa(x) distribution. Magnetrons are not noted for their stability, and are
probably not suitable for CW. I have played with tunable 500 mW klystrons,
and they can drift 10s of MHz (at 12 GHz), in a very short period of time.

73,

Frank


In the article I quoted above they tune the magnetron frequency by
varying the voltage to the magnetron. I wouldn't be surprised if the
oven's DC to the magnetron was filtered lightly or not at all.

--
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Tim Wescott
Wescott Design Services
http://www.wescottdesign.com