Showing posts with label ef-10/20/40. Show all posts
Showing posts with label ef-10/20/40. Show all posts

9 Feb 2013

Par EF-10/20/40 Antenna and a comparison

This afternoon I decided to take down my 10m halo for a while and replace it with a lower antenna: the LNR Precision (was Par) EF-10/20/40 end fed wire antenna, which I've owned for some years but not used recently. As it suggests, it covers 10, 20 and 40m with a very low SWR, although it is a reasonable match on several other HF bands too.

See http://www.hamradio.me/antennas/lnr-precision-ef-102040mkii-test-data.html for an analysis of this antenna.  The antenna works very well and on 40 and 20m WSPR I was getting plenty of spots with 500mW to 5W.
Photo on http://www.hamradio.me website of the Par antenna
On 40m I did a comparison between the horizontal EF antenna and the earth-electrode antenna. A series of transmissions was made with each antenna in turn, then I compared WSPR spot S/N received from a number of stations.

The conclusion is the earth-electrode antenna is around 9-16dB down on the EF antenna on 40m, so averaging about 2.5 S-points down. The test is not too accurate as conditions change, the earth-electrode and EF have some directivity and the reports sample size was small.