Return to KLUBNL.PL main page
| To: | rsgb_lf_group@blacksheep.org |
|---|---|
| Subject: | Re: LF: Fenceline longwire |
| From: | "Johan H. Bodin" <jh.bodin@telia.com> |
| Date: | Tue, 22 Jan 2008 15:27:07 +0100 |
| In-reply-to: | <20080122135712.5D7C8F3862@smtps02.kuleuven.be> |
| References: | <000501c85c3d$4fa2f820$0b01a8c0@weazle> <20080122135712.5D7C8F3862@smtps02.kuleuven.be> |
| Reply-to: | rsgb_lf_group@blacksheep.org |
| Sender: | owner-rsgb_lf_group@blacksheep.org |
| User-agent: | Thunderbird 2.0.0.9 (Windows/20071031) |
Rik Strobbe wrote: It seems that (at least in theory) even 1200 foot is too short to be long on 500kHz ...Or does MMANA not work properly ? Hello Rik,MMANA works very well for free space models but since it is based on MiniNEC, it does not properly model how the "real world" ground interacts with the near field. As far as I know, it uses the ground parameters for the far field calculations only. In other words, I don't think MMANA is able to make meaningful performance predictions for small antennas close to non-perfect ground. I just put a 2000m horizontal wire into MMANA and tried different heights from 1cm to 1m on 500kHz with real ground. Both gain and impedance figures were ridiculous, >600dB gain difference and sometimes the real part of the impedance was negative! :-D Beverages rely on non-perfect ground to work so I saw no reason to trust the radiation patterns either. 73 Johan SM6LKM |
| <Prev in Thread] | Current Thread | [Next in Thread> |
|---|---|---|
| ||
| Previous by Date: | Re: LF: Fenceline longwire, Mike WE0H |
|---|---|
| Next by Date: | Re: LF: Fenceline longwire, GandalfG8 |
| Previous by Thread: | Re: LF: Fenceline longwire, Julian Hardstone |
| Next by Thread: | Re: LF: Fenceline longwire, Rik Strobbe |
| Indexes: | [Date] [Thread] [Top] [All Lists] |