Just cusrious...

What happens if you pipe the output of one radio in to 2 different
amplifiers, and then take the output of the two amps and send them to
two identical vertical antennas spaced a half wave apart and with
equal length feedlines from the amplifiers.

Will the output of the two amplifiers add together in directions where
the signal is in phase, or will it act like two different signals and
interfere with each other?

-Curious

Ponder This wrote in
news


Just cusrious...

What happens if you pipe the output of one radio in to 2 different
amplifiers, and then take the output of the two amps and send them to
two identical vertical antennas spaced a half wave apart and with
equal length feedlines from the amplifiers.

Will the output of the two amplifiers add together in directions where
the signal is in phase, or will it act like two different signals and
interfere with each other?

-Curious


Why would you do that? It's the same as just splitting a single output
from the radio. Depending on spacing and phase you can get of variety of
different radiation patterns. You don't need to split it between two
amps.

I split the output from my radio, lag one 90 degrees, put one in one yagi,
put one in another yagi and get circular polarization.


sc

Ponder This wrote:
Just cusrious...

What happens if you pipe the output of one radio in to 2 different
amplifiers, and then take the output of the two amps and send them to
two identical vertical antennas spaced a half wave apart and with
equal length feedlines from the amplifiers.

Will the output of the two amplifiers add together in directions where
the signal is in phase, or will it act like two different signals and
interfere with each other?
there can be issues with phasing if done right no problem but ifyou are
not good at getting your coax to just the right tlengths

at least that is my understanding

-Curious

Depends--, if in phase, Both INPUT, and OUTPUT,
would add (double power, if SAME power on both,
Also would add, if 180 degrees OUT of Phase, both
Input, and Output. And this would be the same as
with Push-Pull amp (both input, and output). but
if In Phase, on input, and OUT of Phase, on
Output,or vice versa, theoretically, would result
in 0 Output. And, if in different phases, probably
would make a great interference source!!!
(distortion, intermods, harmonics, oddball mixes,
ect!) Jim NN7K


Slow Code wrote:
Ponder This wrote in
news


Just cusrious...

What happens if you pipe the output of one radio in to 2 different
amplifiers, and then take the output of the two amps and send them to
two identical vertical antennas spaced a half wave apart and with
equal length feedlines from the amplifiers.

Will the output of the two amplifiers add together in directions where
the signal is in phase, or will it act like two different signals and
interfere with each other?

-Curious

What happens if you pipe the output of one radio in to 2 different
amplifiers, and then take the output of the two amps and send them to
two identical vertical antennas spaced a half wave apart and with
equal length feedlines from the amplifiers.

Will the output of the two amplifiers add together in directions where
the signal is in phase, or will it act like two different signals and
interfere with each other?

-Curious


I would assume the following: If you use a splitter with an equal
length of coax to the two amps, you would be able to get 100 watts out
from the radio to be 50 watts into each amp. I would suspect that you
would have double the power out to the antenna assuming you used the
same length of coax from the amps to the antenna.

Of course, you have to deal with impedance problems with the splitting
of the coax, for example, two 50 ohm cables would result in 25 ohms to
the amps. Not good. then the two 50 ohm outputs from the amps would
result in 100 ohms to the antenna, not good again....


--
73 for now
Buck
N4PGW

Same affect as feeding two antennas from a single amp. Although it is
sometimes a good way to get more watts/$

Although you have stipulated same feedline lengths there could be some
phase delays inside the amps you dont know about (eg filter components).
You should of course be able to compensate for this by varying line
length. A difference in output power from each will also skew the
radiation pattern.

If the antennas are thus fed in phase and the amps produce the same
power you will get max radiation perpendicular to a line drawn between
the antennas and minimum radiation in line with them. You can play with
all kinds of phase delay/line length and spacing variations to get a
good mix of patterns. They interfere from the standpoint that you get
phase addition and cancellation of the two signals combining. This is
how driven array antennas work.

Do you have a specific application in mind?

Cheers Bob VK2YQA

Ponder This wrote:
Will the output of the two amplifiers add together in directions where
the signal is in phase, or will it act like two different signals and
interfere with each other?

-Curious