[HCDX] Antenna-Showdown in Denmark

[Martin Elbe <elbe@xxxxxxxxxxxx>]

Hi,

I just returned from a DXpedition to Denmark. From 20 to 27 September I
was guest in Wilhelm Herbst's house near Fjerritslev in northern
Jutland. Wilhelm bought an old farmhouse up there in the middle of
nowhere. And he converted the farmhouse into a DX-receiving station. On
an area covering 4.4 hectars he constructed a lot of antennas. Apart
from some longwires (25 and 44 meters, a 6 m Vertical) there are the
following Beverage antennas:

150°  160m
180°  140m
195°  160m
210°  160m
220°  120m
230°   90m, in Winter up to 290m when the neighbouring farmers don't
            need the fields.
245°   80m, in Winter 270m.
260°   80m
270°   75m
280°   75m, in Winter 250m.
290°   80m
300°   90m
315°  240m
330°  175m
345°  330m
  0°  330m

OK, in northern Finland or Sweden an antenna of 80m is not regarded as a
Beverage antenna, but don't let us be more catholic than the pope. ;-)
All antennas are supported either by bamboosticks or by tomato-sticks,
height about 1.5m, the antennas are grounded via a resistor at the end.

And then there are antennas for FM-DX (an 8-element Yagi with Rotor and
TV antennas). Alone on FM more than 1300 stations from 32 countries were
logged so far. Not bad at all!

Anyway, a nice selection of antennas to choose from, and Wilhelm rents
out his home as a "DX-Hotel". He has 3 guestrooms and space for 3 DXers
to listen. Accomodation is cheap, in summer it's 90 DKK (less than 11
US$) per day, in winter it's 120 DKK. Interested? Contact Wilhelm
Herbst, Husbyvej 183, DK-9690 Fjerritslev for more information.

All antennas can be selected via switchboards.

I had my Wellbrook K9AY with me to compare the performance of this
antenna in relation to the Beverage farm.

Concerning the K9AY here are some quotes of Wellbrook's Webpage,
http://www.wellbrook.uk.com/K9AY.html


The Wellbrook antenna provides a cardioid reception pattern with up to
30dB front-to-back ratio over a very large bandwidth. The antenna uses
two Delta Loops with a reversible beam direction to provide a 360 degree
coverage.

A unique feature of the K9AY, is the Remote Controlled Variable
Termination. This allows the user to optimise the null during changes in
the arrival angle of interfering signals and provides a considerable
improvement in reception quality.

The K9AY is specifically designed to simplify the construction of this
Loop antenna. The K9AY comprises of two assemblies: Antenna Control
Unit, and an Antenna Head Unit.

The Antenna Control Unit provides the antenna control functions,
supplies the power to the Antenna Head Unit, and feeds the signal to the
receiver. A 10-15dB Broadband Amplifier is fitted. The Antenna Head Unit
provides the variable antenna termination, Beam Reversal and the Loop
selection electronics. Integrated into the Antenna Head Unit is a 9:1
Balun. This Balun has the feeder winding isolated from the antenna so
that the antenna is magnetically coupled to the feeder. This reduces
antenna/feeder interaction and mains borne noise from TVs, computers
etc.

The K9AY antenna uses a coaxial feeder cable without an antenna tuner.
Low noise performance is assured because there is no antenna return path
to mains earth. The K9AY, is also suitable for non-directional short
wave reception and will provide far lower noise performance (similar to
the T2FD) than an equivalent length Longwire antenna. The electronics
are encapsulated in synthetic resin to form a weather proof
construction.

Comprehensive operating and installation instructions guide the user to
a easy and safe erection. The K9AY is supplied complete with an Antenna
Control Unit, Antenna Head Unit. To operate the K9AY, the user must
provide a 12volt regulated Power Supply, antennna wire, the 50 ohm
feeder cable and the twin lead control wire.


K9AY FEATURES 

· Up to 30dB F/B ratio 60kHz to 2MHz · Lower noise than Longwire  
· 2 Loops for 360 degree coverage · Coaxial feeder reduces local noise 
· Variable Null depth control · Static discharge path to earth 
· Rotary beam direction control  · Optional 10-15dB amplifier 
· Omni-directional up to 30MHz · Weather proof construction 


K9AY ANTENNA

This antenna was originally designed in the US by a radio amateur, Gary
Breed - K9AY, and has been used successfully used by radio amateurs and
medium wave listeners.

The unique feature of the K9AY is the constant high front to back ratio
over a very large bandwidth. The K9AY is probably the only medium size
passive antenna that can provide a significant improvement to medium and
long wave reception.

The antenna simply requires up to two 25m wire Loops. A single 8m
vertical support is required such as a tree. However, it is important
that the antenna is erected away from buildings and sources of
interference. The K9AY only requires an area of 9m x 9m to complete the
erection. Thus, it will fit into most gardens.


SETTING UP THE BEAST

So much from Wellbrook. To erect the Loops I had my Spieth-mast with me.
That's a telescopic fiberglass mast, fully erected 10m high, collapsed a
little bit over a meter long and about 1.5 kg of weight. For earthing I
used a 1m long copperpipe, the earth was rather wet, so that seemeed to
be enough. On sandy soil, rock or under other poor earthing conditions
you may use a counterpoise instead. Both loops had a length of 20
meters. My fault that I did not take more with me, I think a little bit
more wire would have given better signals.

Construction was rather simple. First I hammered a broom-stick into the
soil. Then I connected both loops at about 7m height at the mast. Then I
erected the mast and putted it over the broom-stick. Then I used 4
tomatosticks to fix the loops around the center mast. That proofed to be
a bad solution. Next day I went to Fjerritslev in order to buy 4 tent
pegs instead. I couldn't find any, so I bought 4 Kebabspits and a
Nylonrope. With that I could easily fix the antenna.

Of course the Spieth-mast bended like a bow, but that's pretty normal
and just an aesthetic problem. The mast sometimes tends to collapse
under windy conditions, so I fixed the elements with a bit of force. No
good idea: That turned out to be really bomb-proof when I dismantled the
antenna after a week and there was a lot of swearing and four-letter
words until the mast was fully collpsed. :-) Better use a bit of tape to
fix the elements.

Setting up the antenna took me about 40 minutes from unpacking till the
antenna was up. Another 20 minutes to run all the cables through the
house to the antenna head. All in all less than an hour and I was ready
to listen.


AND THE RESULTS?

Now to the results. My main interest is MW from Canada and USA, and
there the K9AY was inferior compared with the Beverage-antennas. In
about 80% of all cases the Beverage had a louder signal with absolutely
no background noise. In 10% of the cases both where on par and the rest
the K9AY had the edge. Mostly in cases where european splatter was
strong, like KNR Greenland on 650 kHz. But the hammering signals of CHVO
560, VOCM 590, VOWR 800 or CJYQ 930 were more impressive on the
Beverages. S-meter pegged to S9+20 dB is an impressive show! Nothing can
top this.

But when I compared the K9AY to the two longwires there were worlds
among these antennas. The K9AY had always the edge (valid for SW
stations too). Compared to the longwires the K9AY was much more immune
against any kind of noise. Even in this quiet surrounding this was an
issue. The more in an noise-infested surrounding!

When listening on the 9 kHz european channels the K9AY was very often
better than the Beverage antennas. For example I heard HLAZ Korea on the
K9AY almost like the proverbial local station. Simply by "switching off"
County Sound, and then HLAZ was on top. Nothing on any of the Beverage
antennas! Simply because County Sound was audible on any antenna. OK,
with a phaser it would have been easy to phase out County Sound, but
without one you could forget Korea.

Next example: 1557 kHz, Family Radio from Taiwan. Again, I "switched
off" France, and in the remaining mess of croatian and UK stations they
came through. Nothing on a barefoot Beverage antenna. Wilhelm tried it
with his SEM phaser, reception then was on par with my K9AY.

OK, in these cases there was no beverage pointing towards Asia
available, only the backbeams of some antennas. But even when the
desired station was in the beam of the Beverage it was not always
possible to get this station. An example was 1314, with the powerhouse
from Norway and Italy sharing frequency. Not a beep from Italy on the
180° Beverage, with the K9AY I could switch back and forth between Italy
and Norway. If you're interested, I made a real audio file (91 kB) of
this and you can listen for yourself.

No problem at all when you use a phaser, but the pure Beverage didn't
make it.

Amazing, but reception during daytime was usually better on the K9AY
than on the Beverage-antennas. E.g. R. Bloemendaal, 1116 kHz, came in
best on the K9AY at 1340 UTC. Or the UK local "Fresh AM" on 936 kHz was
absolutely in the clear on the K9AY, while on every Beverage there were
traces of Radio Bremen.


RESULTS ON SW

I had expected that the K9AY would show at least a little bit of
directivity on 90 and 60m. But no, it behaved like an omni-directional
antenna. In every case better than the longwire, but the
Beverage-antennas had better signals. On some frequencies one could
separate stations easily with the Beverages. E.g. 11955, where I had
Angola in french and a Chinese speaking station. Switching to the 180°
antenna left nothing from the Chinese, only Angola was audible. Another
example was 11925 kHz, R. Bandeirantes and a Chinese.

The K9AY brought good and strong signals, very clean. But compared to
the appropriate Beverage it came only out as second winner. Only on very
high frequencies the K9AY had the edge, WJFP on 25870 kHz was audible
only the loop.


In general, the K9AY turned out to be an excellent performer, able to
beat the Beverages in some cases. But: Who of us has the space to erect
16 Beverages? But many of us will have a piece of garden of 8x8 meters!
If you have a garden, you should really consider this antenna!

73 Martin


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