tag:blogger.com,1999:blog-9071048343455395511.post2205167805592250654..comments2024-03-24T22:03:31.205+00:00Comments on Roger G3XBM's (Mainly) Amateur Radio Blog: 160m this evening so farRoger G3XBMhttp://www.blogger.com/profile/13673890140751539870noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-9071048343455395511.post-25665136648253402002015-02-22T12:14:35.967+00:002015-02-22T12:14:35.967+00:00Hi Roger,
Agreed WSPR is an amazing mode for expe...Hi Roger,<br /><br />Agreed WSPR is an amazing mode for experimentation and opens up a lot of possibilities that would otherwise not be practical or feasible.<br /><br />Keep up the good work.<br /><br />Regards,<br /><br />Martin - G8JNJAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-9071048343455395511.post-25734446547706729922015-02-22T11:44:06.961+00:002015-02-22T11:44:06.961+00:00Whatever the theory, it certainly proves getting o...Whatever the theory, it certainly proves getting out on 160m WSPR can be done a number of ways and a big antenna down the garden is NOT needed.Roger G3XBMhttps://www.blogger.com/profile/13673890140751539870noreply@blogger.comtag:blogger.com,1999:blog-9071048343455395511.post-17873596834317923232015-02-22T11:41:40.941+00:002015-02-22T11:41:40.941+00:00Martin, I am not easily able to compare antennas. ...Martin, I am not easily able to compare antennas. At MF (472kHz) and LF (136kHz) I am pretty convinced it is a loop but at Top Band and higher frequencies all bets are off! You could well be right.<br /><br />Thanks for reading and commenting.Roger G3XBMhttps://www.blogger.com/profile/13673890140751539870noreply@blogger.comtag:blogger.com,1999:blog-9071048343455395511.post-8266517894883521472015-02-22T10:48:06.735+00:002015-02-22T10:48:06.735+00:00Hi Roger,
Interesting experiments, although the s...Hi Roger,<br /><br />Interesting experiments, although the skeptic in me is thinking that the ground isn't really forming the bulk of the antenna. I suspect it's the interconnecting wire lying on the ground connecting the ground spikes that's radiating, like a very low Beverage antenna.<br /><br />Googing 'Grasswire Antenna' will throw up lots of references to this sort of antenna.<br /><br />Can you perform A/B comparisons with any other antenna that could be modelled along with the earth spike antenna ?<br /><br />I'm thinking that a low Grasswire antenna main lobe would be about 10 to 20 dB down on a Vertical or Tee along its line of fire from feed point to far end termination. Back to front ratio on the Grasswire would be in the region of 10dB.<br /><br />One other test would be to perform A/B comparisons with the far end ground spike connected and disconnected.<br /><br />What antenna current can you obtain with the far end ground spike connected and disconnected (assuming you can match both to the TX).<br /><br />Regards,<br /><br />Martin - G8JNJAnonymousnoreply@blogger.com