|Subject:||Re: LF: Finbar's Compact 500kHz Vertical|
|From:||Rik Strobbe <[email protected]>|
|Date:||Tue, 17 Jun 2008 15:19:35 +0200|
|References:||<[email protected]> <[email protected]>|
But in general I feel that antenna height should not be disregarded. Even with equal ERP sky waves may develop better from higher aerials.
I guess that the only cause that 2 antennas fed with the same ERP produce different signals is a difference in the (vertical) radiation pattern, ie. the takeoff angle.
I simulated a 30m, 10m and 3m vertical (at 502kHz) with mmana_gal and found only very small differences: from 18.2 degrees for the 30m vertical to 18.6 degrees for the 3m vertical. This for a uniform ground with a conductivity of 10mS/m.
Making the ground poor (1mS/m) results in a takeoff angle of about 26 degrees (+/- a few tenths depending on the height).
Increasing the conductivity to 100mS/m reduces the takeoff angle to 12-13 degrees.
73, Rik ON7YD - OR7T
Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm for more information.
|<Prev in Thread]||Current Thread||[Next in Thread>|
|Previous by Date:||Re: LF: vo1na, jcraig|
|Next by Date:||LF: 500 kHz - G3ZWH in France, Chris Osborn|
|Previous by Thread:||Re: LF: Finbar's Compact 500kHz Vertical, hajo . brandt . dj1zb|
|Next by Thread:||Re: LF: Finbar's Compact 500kHz Vertical, hajo . brandt . dj1zb|
|Indexes:||[Date] [Thread] [Top] [All Lists]|