Living on a small lot in a city with height restrictions,
my antennas are limited and especially so for the lower
HF amateur bands (160/80m). While 160m DXCC may be out
of my current reach, I do enjoy the band on CW during the
winter. One of my current goals, however, is the 5BDXCC
lacking only completion of 10m and 80m (only 37).
On the lower bands (IMHO) DSP (AF/IF) filters are helpful.
Still, last winter, my problem was not being heard (running
~1.5kw), but rather hearing on my 55' shortened half-sloper.
A receive antenna was employed (160' center fed inv vee) and
did have lower noise and provide better copy for many stateside
QTHs. The half-sloper did seem to receive better for the far distant
states on the east coast (also JA).
Many told me that they heard me, but I could not pull them out of
the noise. In a series of skeds with N1RJ in ME on 160m, he heard
me every night, but I copied him only the third time (he gave me a
589 and I was struggling during fades).
The same sloper works on 80m, but generally the inverted vee is
used for both tx and rx despite being low. I have modelled the
low 160' dipole with ELNEC and most RF goes into outer space.
Still, QRO, the problem remains primarily rx (as far as I can tell).
For 80m a vertical was suggested, but I lack the area for radials,
hence the sloper. Sloper or vertical, many say noise is a more
troublesome with vertically polarized antennas especially for those
of us who live in urban areas.
Recently, it was pointed out that my rig with the RX-ANT IN and OUT
jacks can be easily interconnected with a "noise canceller" which is
then placed in and out of line by merely pressing the RX-ANT switch.
These devices rely on a good "noise antenna" to provide signal which
is combined with the "receive antenna" out of phase to cancel noise.
Unfortunately, the author of that post was using an antenna better than
mine just for the "noise antenna."
Anyone have experiences with the JPS ANC-4 (I think) or other devices?
Some reported disappointment, but it ALWAYS seemed to be a poor "noise
antenna." Anyone have technical, anecdotal, or other performance data
under similar circumstances? What is a good noise antenna?
What is else practical with poor soil, 35' height limit, and limited
space? Obviously, I can't put out a beverage, but some have mentioned
the use of small (coiled) loops?
Any other ideas? There is likely already sufficient IF/AF DSP filtering.
(FT-1000mp both 500hz and both 250hz filters/EDSP and outboard audio DSP)
Gotta hear 'em to work 'em! 73, Brian
Brian Short 1994 E Laguna Dr Tempe, Az 85282 (602)839-3484 ke7gh@qsl.net
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