LF: Re: Earth electrode antennas

[Roger Lapthorn <rogerlapthorn@gmail.com>]

My (just) 20m spaced earth electrode antenna got plenty of WSPR reports with around 1mW ERP on 500kHz Mal with my best DX report received from 418km. Even on 136kHz my 10-20uW ERP QRSS3 signal got over 100km with this same antenna. On VLF it allowed me to copy DK7FC/P from his kite on 8.97kHz on my first try. He was much better on my 80m square loop though, which was erected later. 

My 500kHz measurements suggested it was only about 8dB down on my 80m sq vertical loop that worked pretty well. 

Summary: earth electrode antennas are not as good as a well elevated Marconi or loop, but work surprisingly well considering how simple they are to excite and match. 

73s

Roger G3XBM

-- Via my 2.4GHz transceiver --

On 1 Jul 2012, at 09:04, "mal hamilton" <g3kevmal@talktalk.net> wrote:

Someone forgot to mention the 1 K/watt pumped into this antenna, no good for QRP merchants.

I tried this method years ago on a hotel flat roof in Hongkong and although I did work a few stations it was a POOR performer compared to the same dipole elevated --- big difference

I was running about 100 Watts to the dipole

There is no substitute for an Antenna being elevated into the air as high as possible except short range high angle communications is required, then a low dipole has an advantage.

 

 

de mal/g3kev

 

 

----- Original Message -----

From: Robert Bennett

To: rsgb_lf_group@blacksheep.org

Sent: Saturday, June 30, 2012 8:40 PM

Subject: LF: Re: MF dipole

 That means, for a MF dipole test i would start to try to lay it
> on the ground. If this works with reasonable efficiency, so that a QSO
> is possible, it would be a simple solution for a quick /p MF antenna
> that can find its place in a back pack!
>

Like K3MT's Grasswire antenna?.

73 Robert