On Feb 2, 3:28 pm, "Francesco L." wrote:
I'm assembling a switch box for a 2 element vertical phased array. My idea
is to create a system able to generate two alternate (and switchable)
cardioids using a delay line (90°, 1/4 wavelength) and a two ways, two
position relay in order to cover with an agle of 120° degrees one direction
(e.g. North) or the other. As you all know, if two elements are fed in
perfect phase the radiation pattern obtained is called broadside. This is
exactly what I want to obtain introducing a second relay in order to get a
third direction. At this point my question is: should I put a 10 w 100 ohm
resistance (non inductive) between the two antennas (it's called Wilkinson
power divider or power splitter) or the system works perfectly that way?
There are two different school of thought: the first consider the wilkinson
a must, since it lowers the swr and keeps it under control, the second
school thinks it burns useful power and does not transfer all power.
So what's your point of view?
Thanks a lot in advance for your contribute
Francesco ik8vwa

--
E il marconista sulla sua torre,
le lunghe dita celesti nell'aria,
riceveva messaggi d'auguri
per questa crociera straordinaria.
E trasmetteva saluti e speranze
in quasi tutte le lingue del mondo,
comunicava tra Vienna e Chicago
in poco meno di un secondo.

E la ragazza di prima classe, innamorata del proprio cappello,
quando la sera lo vide ballare lo trovò subito molto bello.
Forse per via di quegli occhi di ghiaccio così difficili da evitare,
pensò "Magari con un pò di coraggio, prima dell'arrivo mi farò
baciare".

Francesco DeGregori

If the loads are equal and they are fed through equal lengths of line,
then a resistor between them (I assume you mean at the transmitter end
of the feed lines) will never dissipate any power, since it has equal
voltage at each end.

A Wilkinson splitter (or combiner) is used to provide isolation
between the loads, so that if one load is disconnected, the other load
still receives the same power. As a combiner, it isolates the sources
so that power from one source doesn't get into the other source; this
is very useful for combining generator outputs for intermod
testing...but it does depend on proper loading of the output port, and
it's only good at or near the design frequency.

Cheers,
Tom