The 700 receiver system is contained in a 3½" frame
and features microcomputer electronics that control
and monitor operation of either one or two receiver
modules and the LNB. Primary power is normally
117 vac with 240 volt units available. Rack mounting
is optional.
v Input signal to the receiver is L band at
950-1450 MHz and is usually supplied by an
LNB with ±50 kHz stability.
v
v A "relative" RF signal meter monitors amplitude
of the carrier at the demodulator of the first audio
channel. The position of the meter needle may
be changed with the adjustment directly below
the meter. Any variation from this setting will
then be due to a change in the strength of the
received signal. Therefore, it may be used for
peaking the dish and/or day to day monitoring of
system stability, such as dish movement or
cable problems.
v Frequencies of the C or Ku band satellite and
the SCPC frequency are entered through a
keypad. --We use the satellite frequency, rather
than a transponder number, because of the total
lack of any industry standard relating to a
transponder numbering system. They are
displayed on the top line of the backlit
alphanumeric readout. The bottom line of the
readout gives the results of the fault-monitoring
duties of the processor. The front panel of the
700 frame is sloped to make it easy to read the
LCD display and enter data through the keypad.
v The audio meters are backlit with LED's (low
brightnes level is normal). Light is red if the
channel is in a signal failure (squelch) mode and
is green in normal or squelch defeat operation.
v Squelch of the output audio signal is provided by
circuits that listen for high noise levels. The
squelch may be defeated with front panel
switches located next to the audio meters.
Standard receiver modules are for 15 or 7.5 kHz
audio signals, with others available on special order.
Baby boards on the receiver modules contain audio
process/companding circuits for the particular
system. Deemphasis time is selected with jumpers.
Both balanced and unbalanced output connectors
are provided on the rear panel.
A 70 MHz output is provided for use with external
demodulators. Mode C contacts of a fault-alarm
relay are available at the back panel
General Information MA700OVW.sam
SECTION 11
Operating the Zephyrus 700 Series
SCPC Satellite Receiver
General information