AmateurRadio.com

It looks like the Microvert antenna may have originated in Japan? The Microvert is a very compact antenna. Some believe the coax is a major part of the radiating system. Having never tried this sort of antenna I am unable to comment.  This was posted to the Microvert Yahoo group earlier:

Whether you believe it’s the coax radiating or not, this is still interesting:

The Super Rad Antenna (Induced Secondary Radiation Antenna)

	The Super Rad Antenna (Induced Secondary Radiation Antenna) The Super Rad Antenna (The Induced Secondary Radiation Antenna) was thought up in 2006. It has high performance although small size.
	View on t54979899.blogspot.co.uk	Preview by Yahoo

There are other websites about SRA (secondary radiation antenna), but unfortunately all in Japanese. Its definetly a Japanese thing!

I have all the parts required here to make one of these. Whether you believe its the coax radiating or not the results will be interesting.

Rob
M0RZF

PS. My old 10m/12m modified microvert gives a good SWR.

See http://t54979899.blogspot.co.uk/?view=classic.

Quite a few people who use WSPR use the tiny Microvert Antenna whose design seems to have originated in Germany. For example, this diminutive antenna is only about 30cms long on 28MHz. It uses the coax intentionally as a counterpoise with an RF choke the right distance down the coax. Performance is several S points down on a full sized antenna like a 1/2 wave dipole. With small antennas there is always a compromise! Versions have been made for most HF bands. The  antenna looks ideal for portable or balcony use, being small and easy to erect. Perhaps I should test my (currently poor) build skills by making one for 10m or 20m WSPR use?

I wonder who reading this post has used a Microvert Antenna and how they found it?

See http://download.antennex.com/preview/archive4/Apr601/microvert.pdf .