> >I simply don't understand how some
>> of these guys can be SO STRONG, abiding by the rules for power, and still
>> not
>> hear my 1.4 kW signal!
>>
>> Jim K9YC
>
> Jim if you put a dozen or so local W6 stations calling CQ within 5 Khz of
> you... just how many
> DX Stations calling do you think any one would hear? Same problem as many
> EU's clg CQ
> close to each other.
What we are dealing with is signal to noise at the far end. In no
particular order....
After listening to 40m on a big 5 element quad using a K3 in a major
contest, by contrast it is quite clear that one layer of crud in the
signal-to-noise can be created by receivers. Viva technology.
There is local manmade noise. There is natural noise.
There are good RX antennas, and not-so-good to malfunctioning RX antennas,
and then there are no RX antennas at all.
So far all of that is out of our control.
Then we come to our transmitting antennas.
A simple swipe of the RX up and down the band reveals the completely
remarkable variance in what kind of signal is actually coupling the
propagation from stations who all report high power in the 160 contests year
after year.
There are a handful who run 4-squares. The ones I know about are over
commercial grade ground radial systems. HOWEVER, the 4-5 dB advantage of the
four over the one vertical does not explain their strength. Even if I take a
cynical stance and say that not only are they running 4-squares, but also
running 10 kW using secret 3CX10000A amplifiers, not even the 12 db explains
it. There is still another 5-10 dB advantage after that.
Can someone explain to me how two high power stations are separated by
upwards of 20 db, consistently, year after year, contest after contest, good
conditions and bad?
I must reluctantly come to the conclusion that most 160m transmitting
antennas suck. Some suck quite more than others.
A minor amount of statistical work in the email archives will indicate that
most station operators get the SWR to something reasonable. If SWR
correlated to effectiveness, most 160m transmitting antennas would not suck,
but by prior observation most do suck. Therefore the problem with sucky
160m transmitting antennas has nothing to do with SWR.
The really interesting revelation came when I decided to use computer
modeling to model the suckiness of 160m antennas with the software of the
day.
If I used the "ham-grade" programs (aka cheep), I could not come up with
nearly enough suckiness to model what I was hearing. After some soul
searching, and a few deep breaths, I took the plunge for the industrial
grade versions of these programs (more than a couple K investment for all of
them) and started searching for a clue for something that would explain the
suckiness.
Without espousing the boring details, one CAN properly model observed
suckiness on 160m by modeling dirt and all the miscellaneous conductors in
the vicinity.
Antenna configurations widely touted on this reflector and elsewhere can be
degraded with a reality-imitating level of suckiness by adding dirt and all
in-field conductors (or lack thereof) to the models. While these are a
royal pain of irritating detail to add to a model using an expensive
program, the conditions they model are common. Further, these RF sucking
conditions are infrequently engaged in the various email threads that pass
by here, dwarfed by the attention to SWR.
To get back to the original thread, I reluctantly must offer that the last
reason why we don't get heard, is our TX antenna suckiness factor exceeds
whatever signal-to-noise advantage the far side may have garnered in their
RX antenna.
73, Guy.
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