View Single Post
  #4   Report Post  
Old November 30th 05, 02:54 AM posted to rec.radio.amateur.antenna
W. Watson
 
Posts: n/a
Default C. Crane's Twin Ferrite Antenna

Tim Wescott wrote:

W. Watson wrote:

I bought this antenna on a 30 day trial, and just got it about 12
hours ago. So far I'm not at all impressed. I live about 150 miles

.... snip

during that period. In fact, quite listenable. All this without the
device though.

I'll continue to experiment, but so far not so good. Comments?



I'd change the power supply to a better brand.

Generally if you have atmospheric or man-made noise increasing the
antenna efficiency is just going to increase the noise along with the
signal.

You could try to make a directional antenna; this would increase your
desired signal more than your noise.

The antenna would have to be big, however. The wavelength at 800kHz is
somewhere around 370 meters and you'd need to use around 1/4 of this.

You could try to feed power supply noise to the radio antenna at just
the right amplitude and phase to null it out. This would be a good
subject for an undergraduate or even a Master's thesis in EE but
probably not a good thing to do in practice.

You could attempt to shield it. Rat Shack has some clamp-on ferrites,
you could put one of these on your power cord close to the end that
plugs into the power supply. You could also make sure that the PC case
is well shielded.

I tried the RS ferrites and they made no change. I even took barbell weights
and put them on the AC line of the PC. Zippo. If I hadn't already spent $60
for the new PSU six weeks ago, I might think of buying a much better one.

In some way this may be circuit dependent. I do believe I plugged in my
other PC to the same socket and had the same experience; however, when it's
plugged into its normal socket, there is no noticeable change.

Interestingly, bad weather moved in yesterday and today, and reception from
the station has been quite good with the normal antenna. This stuff can get
pretty strange.

--
Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

Traveling in remote places in the winter. What's the best
tool to carry with you? An axe.
-- Survivorman, Discovery (SCI) Channel

Web Page: home.earthlink.net/~mtnviews