[Antennas] VSWR on Log Periodic.

2002年4月24日 20:03:11 -0400

I have an 8 element LP [Tennadyne T8] at 40 feet on Rohn 25 over New
England soil. Tonight temp is 45F, Humidity is 50%, soil is average New
England with grass growing without irrigation. It slopes off by 10 feet
to the north. 
I made some claims regarding VSWR from 13 MHz to 33 MHZ. Attached are
the actual readings at my location using both the VSWR meter in ICOM 746
and a Daiwa CN 101L
Frequency	VSWR
14.0		1.3
14.1		1.3
14.2		1.3
14.3		1.4
14.35		1.4
18.07		1.5
18.17		1.4
21.0		1.7
21.1		1.7
21.2		1.7
21.3		1.6
21.4		1.5
21.45		1.5
24.89		1.5
24.99		1.7
28.0		1.8
28.1		1.7
28.2		1.5
28.3		1.3
28.4		1.2
28.5		1.1
through 29.5	1.1 [every 100KHz from 28.5 to 29.5 is 1.1]
29.6		1.2
29.7		1.2
Not bad for a nominal 5.8 dBd antenna. These readings are unique to my
location and should be used only for nominal purposes of supporting my
assertion that a LP is uniformly a VG antenna across the 20 meter to 10
meter ham bands.
Dave, W1MCE