QTH here is Peachtree City, GA, about 20 miles south of Atlanta. Peachtree City is a large golfing community with 3 golf courses and 88 miles of golf cart paths! So, much of our local travel (to the grocery store, drug store, etc.) is by golf cart. See more about Peachtree City at http://www.peachtree-city.org/.
Rig here is a Flex Radio Flex-3000 with 100W output. The antenna tuner is a Denron Clipperton-T. Antenna is an 80-10M OCF dipole at 60 feet and a 10M Solarcon A-99 vertical at 70 feet. I have a brand new Ameritron AL-1500 amplfier, not yet in the picture. Also not in the picture is my Henry 3K amplifier. All of them give a solid 1500W output on HF bands.
I like 10M FM the most, but I'm on 80, 40, 20 and 15M sideband too!
The OCF dipole uses 63 feet of 450-ohm window line with a 4:1 balun near the ground. Coax attaches to the balun through a surge suppressor attached to a ground rod. The ground rod is important for lightning protection, though I still disconnect the coax where it enters the house during a lightning storm. It only takes a little voltage spike at your receiver input to cause damage, and even multiple ground rods won't fully protect you!
The OCF dipole appears to me to be about the best multiband antenna I have seen. The legs are 46 feet and 92 feet. What helps a lot for me is the 63 feet of 450 ohm window line, which is 1/2 wavelength long on 40 meters, and multiples of that on 20, 15 and 10 meters. That means that the impedance at the end of the window line is about the same as the impedance at the dipole on those bands. The result:
80 meters: SWR is between 6:1 and 2.5:1. I need to use the antenna tuner on this band.
40 meters: SWR is 1.2:1 at 7.1 MHz. Worst SWR is 1.7:1 at 7.3 MHz. Not bad!
30 meters: SWR is 2.0:1 across the band. Surprising that it is that good!
20 meters: SWR is 1.2:1 at 14.2 MHz. Worst SWR is 1.6:1 at 14.35 MHz. Good!
17 meters: SWR is 2.0:1 across the band. Another surprise!
15 meters: SWR is 1.3:1 at 21.3 MHz. Worst SWR is 1.8:1 at 21.0 MHz. Good!
10 meters: SWR is 1.0:1 at 28.5 MHz. Worst SWR from 28.0 to 29.0 Mhz is 1.8:1. Good!
So I just can't complain about this antenna!
I recommend and use only LMR-400 coax, which has lower loss than standard RG-8U.
Contact me at firstname.lastname@example.org.
Best of DX to all of you! 73's.
- Steve, WD0HGB
1087451 Last modified: 2014-07-09 05:32:02, 3368 bytes
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