Search String: Display: Description: Sort:

Results:

References: [ +subject:/^(?:^\s*(re|sv|fwd|fw)[\[\]\d]*[:>-]+\s*)*\[TowerTalk\]\s+Understanding\s+Antenna\s+Impedance\s+Measurements\s*$/: 4 ]

Total 4 documents matching your query.

1. Re: [TowerTalk] Understanding Antenna Impedance Measurements (score: 1)
Author: Jim Lux <jimlux@earthlink.net>
Date: Tue, 15 Nov 2005 14:25:28 -0800
I simulated the effect of about 218 ft of RG-8X (180 deg at 1.85 MHz) with a load of 50+j20 ohms, at frequencies from 1.8 to 1.9 MHz. Frequency, MHz 1.8 1.82 1.84 1.85 1.86 1.88 1.9 R at load 50 50 5
/archives//html/Towertalk/2005-11/msg00510.html (10,153 bytes)

2. Re: [TowerTalk] Understanding Antenna Impedance Measurements (score: 1)
Author: "Tod" <tod@k0to.us>
Date: Tue, 15 Nov 2005 15:38:28 -0700
Jim (and Jim) Those values look like they are within about 2% of expected values for the R and within 20% or so on the X. Is the analyzer accuracy any better than that if there is NO coax between the
/archives//html/Towertalk/2005-11/msg00512.html (9,514 bytes)

3. Re: [TowerTalk] Understanding Antenna Impedance Measurements (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 15 Nov 2005 16:49:35 -0600
What Jim Lux has shown by cranking the numbers is that when the VSWR is small, the effect of the transmission line is small. That would be true whether the line was a half wave or not. But when it's
/archives//html/Towertalk/2005-11/msg00515.html (9,882 bytes)

4. Re: [TowerTalk] Understanding Antenna Impedance Measurements (score: 1)
Author: "Tod" <tod@k0to.us>
Date: Tue, 15 Nov 2005 15:56:16 -0700
In the end it is transferring power to the antenna that counts. Unless the VSWR is awfully high and/or the line length is very long I think it is quite stuffiest to put a tuning network at the statio
/archives//html/Towertalk/2005-11/msg00517.html (11,540 bytes)


This search system is powered by Namazu