Showing posts with label 4M. Show all posts
Showing posts with label 4M. Show all posts

Friday, 15 July 2011

4M Dipole and AIM 4170 Antenna analyser

For a change I put back up the 4M vertical dipole I use on FM. After I found
a duff connector in the feed line and did some adjustment to the antenna I
got the following plot, 70 MHz is in the centre. Yes when I connect the antenna
up to a real radio I get the same results as the 4170 measured. This is a great
piece of kit and the latest version of the software includes a TDR function. Which
correctly showed the position of the problem in my feedline. I have had this unit
for a number of years but as I don't do much antenna work this was the first time
I have used it in anger. I think I may be making some more antennas after this
pleasant experience.

The reason for the two overlaid plots is that they show the dipole with about
1cm change in length.