Dick, W7WKR wrote:
"I recently installed a "Tee" antenna with four elevated radials. The
ground conductivity is really poor due to the sand, gravel, glacial-flour
and rocks that make up the local landscape. I live in a narrow (~1 mile
wide) NW/SE running valley with 7000 foot ridges rising above the valley
floor. Other than QRN this place is QUIET.
"The Tee has a 100 foot top section with an 80 foot vert section fed
about 10 feet above ground. The 4 radials are about 125 feet long and
stretch through vine maples and low fir branches. If needs be such, I can
install long Beverage antennae {sic: 'antennas' -- 'antennae' are insect
feelers] to provide directional reception.
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Above-ground radials are no better than on-ground radials unless they are
quite high. Your ten-foot high radials on 160m will perform the same as
if they are on the ground.
If I had that same antenna, I would lay the radials on the ground (and
install many more of them) and feed the antenna at ground leavel. This
would add ten feet to the vertical section which would be beneficial.
If the resonant frequency of your Tee is below 1800 kHz, I would also
reduce the size of the 100-foot horizontal top section to make the
antenna more nearly 1/4-wave resonant at the desired frequency, because
there's no sense wasting your antenna current in high-angle radiation if
DX is what you're after. Also, a 1/4 wavelength vertical (or Tee) will
give you the greatest 2:1 SWR operating bandwidth without having to use a
means of tuning at the feedpoint.
==========
"It has been about 30 years since I was active on 160 from my then
additional station N6HZ in Northern CA. LORAN is gone and the various
operating windows have changed."
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Things have changed considerably on topband since then. Back then, very
few manufacturers provided 160m in their equipment. None of the Japanese
manufacturers did. Today, virtually every manufacturer includes 160m in
their gear (including Elecraft), so you'll find that topband is much more
occupied than it was in the old days (especially in the winter). Signals
are bigger because when LORAN QRTed, the FCC increased the 160m power
limitations to the same as on the HF bands. Also, many stations' 160m
antennas are bigger and better.
The present ARRL band plan for 160m is narrow-band modes (CW and digital)
from 1800 to 2000 kHz, and SSB and wide-band modes from 1843 to 2000 kHz.
There's a proposal in at the FCC that will make this law for US hams if
the FCC adopts the plan. In other words, topband will be segmented just
like the HF bands are (it's about time!).
On CW, it's generally accepted by DXers that the 1830-1835 kHz segement
is a DX "window" to be used for international QSOs only.
The JAs now have priveleges (CW only) on 1810 to 1825 kHz, so we don't
have to work them "crossband" like we used to. They still have their
little 5-kHz band centered on 1910 kHz (also CW only)
==========
"I would appreciate receiving some advice/observations on how well the
Tee antenna I described above might perform along with general operating
procedures such as "don't call CQ here", listen for DX here and listen
there, etc."
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The Tee antenna you described should be a real "killer" for DX on
topband, especially if you increase its efficiency by adding more radials
to it (either elevated or on the ground).
I also recommend that you obtain a copy of ON4UN's book titled "Low-Band
DXing", which is sold at all ham stores and by the ARRL.. There's a
wealth of information in this very worthwhile phonebook-sized handbook.
Welcome back to 160m!!
73, de Earl, K6SE -- West coast 160m DXCC #2 (W6RW was first), #55 in
the world -- Current topband total is 179 countries, none of them with my
K2 (except W), unfortunately.
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