Tuesday, June 28, 2011

WB5ONA describes his station

Every Sunday the ARES-OK HF net is held at 2130Hrs UTC and depending
on band conditions the net is held on either frequency of 7.260 MHz or
3.900 MHz.

Each week during the net several stations come booming in are always
loud and clear. One of the cleanest and clearest such station belongs
to Nelson WB5ONA of Stillwater, OK.

One of the best ways to learn "how to" in amateur radio is ask another
amateur how he or she is doing it. What did they do to build
something, or connect their equipment.

So I asked him… How is your station set up? What radio are you using?
Do you use an amp? If so which? What antenna are you using?
Below is the e-mail Nelson WB5ONA sent back to me just full of great
info. His secret, a good radio, no amp, basic tuner, and home brew
NVIS type antenna.

I hope you enjoy and find the information from Nelson WB5ONA as useful
as I did. My thanks, Nelson, for giving me permission to share his
e-mail with all of you.

73 Mark Conklin N7XYO

>From Nelson WB5ONA:

I use an ICOM 7000 usually running 100 watts. I use the stock
hand-held mike but with the AB5N upgrade. The upgrade makes a marked
improvement in audio and output. I highly recommend the upgrade.
(www.7000mic.com)

I do not use an amplifier.

My antenna is an inverted "V" with two 63-ft legs of woven copper. The
feed line is Radio Shack TV lead-in (not window line). At present, the
lead is around 100 feet, more than enough to reach my equipment. The
extra length is randomly tossed into a flower bed. Coiling introduces
SWR problems. Once the antenna is supported as I hope at a later date,
the lead may be trimmed.

I use an MFJ-969 tuner. This tuner has a built-in 4:1 balun and
balanced-line posts with one post shorted as described in the
operating manual. Using this or similar tuners with the described
antenna enables 80- to 6-meter operation. A 1:1 SWR is possible on
each band, however, not throughout each band.

Contrary to common mind-set that feed lines must be coaxial, twin lead
does work very well and, I believe, delivers more RF to the antenna
than would an equal length of coax.

The center of my antenna is up about 35 ft and is supported above the
house eave with 15 ft of 2-inch diameter schedule 40 PVC pipe. PVC
eliminates any twin lead/metal interactions. On a tower, twin-lead
must be stood off with non-conducting material from any metal by at
least 3 times the lead width.

The PVC pipe I use is topped with a tee. The twin-lead is taped to the
outside of the pipe and enters a slot cut in the side of the tee.
Eye-hole lugs are soldered to the antenna legs and twin leads and
attached together via small bolts extending through the tee wall near
each end of the tee. The connections are inside the ends of the tee.
So, far, this connection technique eliminated breakages I was plagued
with when connecting in other ways.

The free antenna ends are about 20 feet above the ground and are
supported using 2, 3/4 x 2 inch strips of PlexiGlass as insulators
with 1/8th inch holes drilled at each narrow end of each strip. The
antenna ends are looped through an insulator hole, wrapped and
soldered to the leg end. Trimmer (weed eater) cord is used to support
the ends of the antenna. Green trimmer cord blends into sky and tree
colors and is a longer lasting alternative to nylon. I've used trimmer
cord for years and have never had one break or in need of replacement.
The trimmer cord was left long enough to toss the loose end over a
branch for hoisting the antenna legs. To get the cord over the branch,
I attach a vise-grip pliers to the end of the cord and hope for a
lucky toss. The support cord is tied within ground reach. The legs are
not drawn tight to prevent bending the center PVC support. The
resulting inverted "V" is more like a slightly swooping W. The
"V" angle between the legs is kept between 90 and 120 degrees.
A good ground, as with any antenna system is a definite must.

I do get some stray RF at times in computer speakers and on some TVs.
Careful tuning and a good ground on all equipment reduces or
eliminates this problem. The RFI problems also vary by operating band.

This is a great multi-band antenna. It's very portable and handy for
special event and field day operations with appropriate center and
support. It is also great as a fixed antenna as I usually have good
reports from stateside and DX stations. I'm often surprised and
pleased when I manage to come out on top in a pileup.

73,

Nelson Ehrlich, WB5ONA
Stillwater, ok
****************************************************************************************************

Posted by:
Mark Conklin, N7XYO
Oklahoma Section Emergency Coordinator
Amateur Radio Emergency Service
918.232.8346
n7xyo@arrl.net
Follow me on Twitter @N7XYO
www.ARESOK.org

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