AFRTS Defense Media Center Satellite Handbook

Defense Media Center Satellite Handbook V.3.26
Figure 7-1 Wegner system wiring
manufactures supply conversions from unbalance to balanced audio modules:
the Wegner 1659 is one example. Cues tones are seldom audible because of
their sub-audible tone characteristics and short duration before they are masked
by program audio; however, Wegner recommends stripping the tones through
the use of a tone decoder.
The model 1648 tone decoder is capable of handling balanced or unbalance
audio inputs. The two position jumpers located on the end of the decoder card
should be strapped on the dot position for balanced and away from the dot for
unbalanced audio inputs.
Ensure that the audio outputs are properly phased, that is, use the same pin from
each connector to the (+) and (–) outputs. Also, maintain left and right order. By
referring to table 7-1 you will see that if you cross-input a cue such as 25 Hz to
the right channel instead of to the left channel you would receive a cue 2 (binary
10), as opposed to the intended cue 1 (binary 01).
To interconnect audio outputs from the Model 1648 tone decoder to external
equipment, connect J7 (left channel), and J9 (right channel) to the external
equipment. Outputs from the 1659 (Unbalanced to Balanced) card are 600 ohms
balanced signals, pins 1 and 3 are differential balanced audio, pin 2 is chassis
ground. (see figure 7-1 for wiring diagram and figure 7-2 for level adjustments
and).
Controls and Indicators
On the front of the decoder card is an LED activity display (figure 7-2). The
display exhibits, in hexadecimal form, the numeral of the last tone transmitted.
Tones 1 through 9 will be noted as numerals 1 though 9; note 10 through 15 will
be indicated as letters A though F respectively. The green indicator beneath the
LED display will illuminate during the transmission of any tone function. The
indicator will extinguish upon termination of tone, but the led display will continue
7-6