[SMCARA] More antenna fun from W4OKW

Clarke, Tom AIR4.0P NATOPS frederic.clarke at navy.mil
Thu Jun 16 15:42:46 EDT 2011


This is a shortened folded dipole antenna for a
single band. Shortening the dipole raises the 
input impedance and the vertical section is a
9:1 transformer, magically making it 50 ohms
at the balun. Somewhat narrow, but covers most 
of the 40M and up freqs.

73 Tom
                 390/fMHz
___________________________________________
|__________________   _____________________|
	             |  |		 
	             |  |		 
	             |  |	190/fMHz	 
	             |  |		 
	             |  |		 
	             |  |		 
                   ____
                   | B |  1:1 Current Balun
                   ----
                     |    50 Ohm Coax feed (any length)
                     |



Band	Top Section	Vert Section	Remarks
3.3	118 Feet	51 Feet		MARS Freq
3.7	105 Feet	46 Feet		75 Meters
4.1	98 Feet	42 Feet		MARS Freq
5.4	72 Feet	35 Feet		60 Meters
7.2	55 Feet	24 Feet		40 Meters
10.1	39 Feet	19 Feet		30 Meters
14.2	27 Feet	12 Feet		20 Meters
18.15	22 Feet	9 1/2 Feet		17 Meters
21.3	18 Feet	8 Feet		15 Meters
24	16 Feet	7 Feet		12 Meters
28.4	14 Feet	6 Feet		10 Meters
50.15	8 Feet	4 Feet	 	6 Meters
146	2 3/4 Feet	1 1/4 Foot	 	2 Meters

Formula =	390/fMHz	190/fMHz	450 Ohm Window line
		415/fMHz	188/fMHz	300 Ohm Twinlead
No tuner reqd unless trying to force to another Band.


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