PRINCIPLES OF OPERATION
a. 2-Channel Multiplexer TD-1288 ( )/GRC and 5-Channel Multiplexer TD-1289 ( ) (V)/GRC.
Receives and isolates rf energy from transceiver(s) and couples this energy to the broadband
b. Forward Reflected Power Discriminator. Takes a sample of the rf energy transmitted
through the multiplexer and determines the magnitude of forward and reflected power.
c. Input Coupling and Resonator/Central Resonator/Output Resonator and Coupling. Provides
rf coupling and frequency selectivity by means of manually tuned resonators. An rf sample is also
sent to the 90 phasing discriminator by means of the central resonator.
d. Coupling Network. Matches the 7-ohm resistive load of the band-pass filter to a 50-ohm
resistive load of the antenna and optimizes the VSWR across the operating frequency range.
e. 90 Phasing Discriminator. Determines the magnitude
of the phase relationship
energy passing through the multiplexer.
f. 60W Power Level/6W Power Level. A resistive network that allows a full scale meter reading
of 60W or 6W on the front panel meter.
g. Meter Function Switch. Selects phase, reflected power, and forward power at a 60W or 6W
h. Meter. Displays function selected by meter function switch.