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HAM ©
2016
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REVERSE SWITCH (N to 1)
Reverse switches are safety (interlocked)
antenna switches used in reverse direction.
Instead of switching RF from one transceiver
among multiple antennas, they provide the ability
to distribute (switch) one antenna among multiple
transceivers (or transceiver antenna ports). By
design, these switches prevent two or more
radios from connecting to an antenna or each
other at the same time.
The only commercially available switches are the
two way A/BSS switch from Top Ten Devices
and the microHAM Four + Four Switch (two four
way reverse switches in a common enclosure) -
in SMD terms, these switches have one (1) A
port and two (2) or four (4) R ports.
Reverse switches are vital part of every RF
configuration where more than two transceiver
ports are needed.
From configuration perspective, reverse switches
are very similar to double switches but the Rules
and Switching tabs are expanded to support the
additional R port definitions. As is shown on the
picture for 4+4 switch, the InVector for each port
has just 1 bit because each R port is controlled
only by a single wire with ON/OFF state, but all
four InVectors are controlled at once by single
control box unit (not shown).
STACK SWITCH
Stacking switches are special purpose switches made for distributing power to/from
several antennas at the same time while keeping impedance of all antennas matched.
SMD supports all available products, custom stack switches can be added using
Other
selection and knowing relationship between stacked antennas selection and state of its
control port. For explanation we will use the microHAM three antenna Stack Switch,
because it has a unique feature – the SUB port, a separate R port that allows
independent use of any antenna not currently used for stacking on the MAIN port.
The
Interconnections
tab is again very similar to other switches. It shows which RF
boxes are connected to the MAIN and SUB R ports and allows selecting connections
for the A ports.
The
Attributes
tab isn't empty because Stack Switch has two special features. First is
a BOP feature which allows connecting two antennas out of phase (ANT1+ANT2 or
ANT2+ANT3). The second feature called FULL (ANT1+ANT2+ANT3) disables SUB
port of the Stack Switch.
Because Stack Switch has three A ports, the first three bits represent A ports and another two BOP and FULL.
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