Today was the perfect day for installing an antenna. There was absolutely no
wind. It was perfectly calm.
With the help of my neighbor, Robbie, I installed the D40 on top of my new 65'
tower. The D40 is at about 74'. I did not install it on its own rotator.
I installed a new run of RG-214 down the tower and into the shack, along with
the M2 rotor cable. I was a little anxious because I did not know for sure what
the SWR would be. The instructions say SWR results are erroneous when near the
ground. Last weekend when I had it at 17', the antenna appeared to be resonant
down below 7000 Khz with an SWR of about 1.5:1 at 7000 Khz. Since experience
tells me that antennas tend to resonant lower in frequency when near the ground,
I could only hope I got the measurements right. I had double and tripled
checked them.
So I was very happy to find my resonant frequency at 7060 Khz, which is only 20
Khz off from what I had tuned it for. The SWR is flat at 7060 Khz and is below
1.5:1 from 7000-7120 Khz. This is perfect for me since I rarely operate SSB
(the PW-1 will certainly tune the higher SWR up on the phone band).
Not only is it tuned right, it looks awesome up there.
Scroll to the bottom of this page
http://aa5au.com/antennas/rebuild/higher_tower.html
Now I have to build and install an A3S below the D40. That will do for the
Roundup. Then I'll try to spice it up a bit with a 3 element SteppIR in the
spring. The lead time on the SteppIR antennas 2-3 months and I wouldn't have
received it in time for Roundup.
73, Don AA5AU
_______________________________________________
RTTY mailing list
RTTY@contesting.com
http://lists.contesting.com/mailman/listinfo/rtty
|