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 .
Hello Roger.
ReplyDeleteLots of information on the Microvert antenna in Steve G0KYA book 'Stealth Antennas' - interesting.
John - GW3OIN
Thanks John. I don't have that book. Anything I need to know?
ReplyDeleteHello Roger.
ReplyDeleteThere are several pages in the book dealing with the Mircovert. Firstly there is detailed reference to the work by DL7PE. This is followed by the experience of a small number of other users, including G0KYA in building and using this aerial. From a personal point of view I find it easier to follow what is said in the book rather than off the computer (something that applies to most things).
The book itself is one I would very highly recommend. It is now probably my first port of call when it comes to suitable antennas for my QRP activity. But, if you are interested please keep in mind that a new (second edition) copy of this book will become available from the RSGB next month.
Kind Regards.
John - GW3OIN.
Roger.
ReplyDeleteI should also have mentioned that there is apparently a Yahoo MicroVert Group. I can not give any detail as Yahoo and that sort of thing is a bit beyond me !
John - GW3OIN