Dear TopBanders ,
let me share with you my trial experiences with multiple reception from
multiple Beverages antennas. I have come into consequence that somebody
would take advantage of my findings. As fore mentioned on this pages before
I am running a remote controlled QTH successfully for 4 top band seasons
already and belong to lucky low bander having in use 20ha of a flat hill top
space. There are basically currently 6 whole year fixed Beverages 360m long
hardly configured in stararchitecture and I can build one occasional long
long Beverage aimed at every direction of prompt opportunity when low band
Dxpedition is on the air.
I had used a lot of different Beverages configurations during previous years
but this time I have come after into current Beverages configuration as most
efficient for me, DX low bander point a view. Let me conclude briefly why.
Applied to my QTH conditions of course I must underline that I had to solve
problem of local BC transmitter ( 632 kHz ) with 2x750kW phased output power
about 20km straight line from my QTH. Everybody could understand that
spillover this 1,5MW is horrible. So I had to respect this situation when
trying to find the best reception on 160m.
I found that:
Beverages central point had to be connected with telecommunication little
house by special coaxial cables which developed for me a friend OK1MY owner
of cable factory to prevent reception from very high LF field level from
local BC station. The cable was developed as hard line 75 Ohm impedance and
2 additional layers one against magnetic and second against electric field.
The four cables are connecting Beverages central point with shanty in trass
of 400m long. The cables have additional cable sheeting resistant against
water of course, plate against rocky dirt and critters. All the cables I had
to bury 1,5m deep to prevent cables against LF penetration. I found that
initial buried cables in depth of 0,6m against farm machinery was not
enough, after sheeted cables put deeper had become absolutely silent.
Beverage over 800m long is too long and force him work properly meant use
highly conductive stout line wire. Then worked excellently but had too
narrow
reception diagram.( and somebody stoles the Cu wire all the time ).
Beverage 260m long seemed to me not gained enough for use of multiple
reception.
Because having covered 360 deg. reception ways I found that for reception
aimed at 190 deg. ( Africa ) is the best not using simple 336m long (
exception of
length ) Beverage but end fired Beverages 2x336, 7m spacing, 20m staggered.
When tested at other directions an advantage of staggered Beverages was not
so evident as into the south aim. So due to easier maintenance I stand by
enfired phasing at south direction only.
I found that phased Beverages 2x 360m with 90m spacing are excellently
working Beverages system but for me, had too narrow beam and I let the
phasing system for incidental use when wanted to stress reception from
Dxpedition direction.
Multiple Clients Remote Reception.
I was asked by friend of mine OK1FM to joint him for common remote reception
from my Beverages field over a year ago. I did it so that I made up a Magic
T splitters based on Tom´s W8JI idea ( thanks Tom ) and split reception into
2 separate Beverages antenna switches and add TRX, PC and other essential
tools to allow him listen simultaneously but independent. It worked over a
year and helped OK1FM increased 160/80m score considerably. Nevertheless I
was finding some repugnance compare my previous using of my remote reception
when I was there along.
I found that gaining from splitters was lower ( of course ) and we had to
use on ours IC756PROs RX preamplifiers what it not used to be before when I
was using just direct input without preamps.Further I found that when we
both are on remote together there was certain higher noise and take me some
time to find that reason was emitting of noise from one RX into other and
vice versa.
Based on findings above I decided re-build Beverages system for multiple
clients connection possibility point a view too. I found on Jay` s WX0B
pages gear of
I.C.E. Radio Products a professional one an active signal splitters for 4
outputs. I did not have time to build one by myself because was busy with
another project of full sized dipole 4SQR for 160m ( but it is another case
). So the splitters came finally after some problem with delivery. I
installed splitters immediately because all the rest was ready to work. I
don?t want to make any final valuation but let me say that I.C.E. splitters
in spite of being so simple gear are working properly.
I can do now full-value connect four clients into my Beverages system, each
of them independently controlled. Above mentioned noise between RXs
disappeared and gain from splitters is again on good level and nobody
connected is forced to use preamps. Just there is sometimes finding that
Beverage toward BC TX direction has interference background it means that
built in BC filter is not sharp or wall brigs enough, but what could
withstand 1.5MW 20km away ?
Let me allow to apologize to all for whom was my article too long. I wanted
to describe further possibilities of remote controlled QTH`s and idea where
HAM radio is going on thanks to new technologies in telecommunication. Just
raise up a curtain to show other low banders where could go if one loves
low band operation and CW and doesn?t want to leave one for other sort of
modes and bands.
If anybody finds time and has interest can check my pages www.ok1rd.com .
Good luck to all and 73
Jarda, OK1RD and OK7XX from remote
controlled QTH
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