Separate amplifiers could also be problematic unless very carefully designed
and tuned to keep the phase delays the same when changing frequency across a
band.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://wiki.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://k1ttt.net
> -----Original Message-----
> From: Jim Brown [mailto:jim@audiosystemsgroup.com]
> Sent: Sunday, August 14, 2011 21:48
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] Two signals on the same frequency?
>
>
> On 8/14/2011 2:23 PM, Jim Brown wrote:
> > The short answer is that the
> > signals from multiple antennas will ADD algebraically,
>
> One VERY important point is that for the signals to ADD, they must be
> SYCHRONOUS -- that is, on precisely the same frequency,
> coming from the
> same oscillator. In practical terms, this means a signal
> generated by a
> single transmitter, then fed to two power amps that feed different
> antennas. Or a single transmitter (with or without a single
> power amp),
> split between multiple antennas.
>
> If the two signals were not synchronous (that is, from two
> independent
> transmitters) their phase relationships will be random, and
> addition and
> subtraction will be quite unstable and unpredictable.
>
> 73, Jim K9YC
> _______________________________________________
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