Dear Amateurs,

What might I do to improve reception of WHFS using my Wizard Radio ISA card?

I am troubled by mono reception due to insufficient signal strength, movement
and position of people in the room, and interference pickup.

If I could just get some shielded twinax... I need less than 20 feet:

Because the antenna, Radio Shack's best passive antenna, is hung from the
center of the 15 by 15 foot living room, and is connected by a hook directly
above the computer with 300 ohm line. But it isn't an ordinary line.

I figured the end of the 300 ohm line needed to be just like the end of the
dipole that came with the Wizard, so I cut down the center for about a foot,
shaved off the center and spaced the two lines gradually with dental floss to
make an "adapter", ending with them close enough together to be soldered to the
tabs on the 1/8 inch three conductor phone plug that goes into the Wizard.

What I want to try now is get some 72 or 78 ohm twinax, use the braid gounded
to the barrel of the plug to prevent interference, and terminate the braid at
the tip of the antenna with an insulated mount made from Lexan with a square
hole fitting the end plug, and a hole to pass the two inner wires. From there,
I'll run the inner wires, braid free, to posts extending the existing antenna
terminals so that they run in a plane parallel to the main beam.

Is there a spacing pattern I can use for this 28 inch run? Or should I tension
the wires to make a linear spacing pattern from the posts, which are 1 7/8
inches apart, to their entry into the braid at the end of the antenna?

I have already tried a balun but have not tried a 300 to 75 ohm balun at the
antenna, shielded line to the computer, another 75 to 300 ohm balun there, a
length of 300 ohm line, and a cut down the middle of the 300 ohm line to space
the wires closer and closer together until the entry point. Seem like too many
losses.

Thus the twinax and posts. It has the correct impedance at the entry to the
Wizard, maintains it, shielded, to the antenna, and then the shield terminates
and the wires form an air space line adapting to the antenna's presented
terminals. Presumably two air spaced lines there would have 300 ohm impedance.

The antenna has a smaller front passive element, a second passive element at 23
1/2 inches along the beam from the first element, an active element 3 1/4
inches from that, crossed lines to another active element 1 foot from the
first, another pair of crossed lines to an active element at 13 inches, and a
passive element at 16 inches from the last active element.

The lengths are passive, shorted, 49 inches, another just like it, active,
open, 43 inches, and then 56 inches, then 58 inches, then the final passive,
shorted element 66 inches. The shorted elements are shorted together and to the
beam. All elements fold with care, but I broke one passive element latch
figuring that out. You have to pull the latch to fold the element. They're all
nearly parallel. They can all be refolded and redeployed with care. I intend to
keep this antenna for a long time. I just love my WHFS.

This is a distance of about 55 miles over roads.

The antenna is rated to 110 miles.

The Wizard obviously has a weak input section, but it has tuning in 0.05 MHz
steps.

I can receive WHFS on 99.1 MHz, and on 99.05 and 99.15, but at 99.0 there's
another station from 98.7, and at 99.2 there's a station from 99.5.

[98.70] [99.00](99.05)(99.10)(99.15)[99.20] [99.50] tuned
[98.70] [98.70](99.10)(99.10)(99.10)[99.50] [99.50] received

like that, see. During the day. At night it's worse.


Yours,

Doug Goncz ( ftp://users.aol.com/DGoncz/ )

Read about my physics project at NVCC:
http://groups.google.com/groups?q=dgoncz&scoring=d plus
"bicycle", "fluorescent", "inverter", "flywheel", "ultracapacitor", etc.
in the search box