Skytrax 9500 Multiplex
From 1 to 634 channels, 4KHz to 2540 KHz
The Series 9500 System provides wireless extension of up to 634 voice or
data lines when used in conjuction with a microwave radio. Landline extension
is also possible.
Frequency-synthesized; all modems are identical
9.6 - 57.6 kbps data capability
Easily field-expanded and rechanneled
Data or Voice
The Skytrax is designed to provide optimum economy and flexibility for
a broad spectrum of communication system applications - particularly those
which contain spurs and multiple drops.
Channel selector switches and passive channel combining allow frequency
reassignments and system expansion to be accomplished readily in the field
with minimal system disturbance.
The baseband spectrum follows the CCITT recommendations for 612 channels
using supergroups 1 thru 10 plus group A. In addition, 2 channels are available
between 4 kHz and 12 kHz, plus 20 interstitial channels between supergroups.
In its most economical configuration the Series 9500 multiplex synchronizes
on the received 3825 OBS tone. In this self-sync mode each channel stands
alone and is independent of all other channels.
In another configuration, using optional sync modules, the Series 9500
multiplex will operate end-to-end with other CCITT multiplex units.
Each Series 9500 modem contains a switch programmable frequency synthesizer
which allows it to operate on any 4 kHz and 2540 kHz. Other than the channel
selector switch no other adjustments are necessary to change the channel
frequency. Since all channels are identical the need for multiple spares
is greatly reduced and field change of equipment is easily accomplished.
Signaling is accomplished using a 3825 Hz out-of-band signaling tone. A
switch in the 9500 modem allows selection of normal or inverted signaling
functions. Front LED's show the status of the E&M signaling at all
times. An internal strap provides "E" lead contact protection if required.
Four synchronization modes are available:
Self Sync Mode
In this mode, which requires no common equipment, each channel individually
synchronizes on the received 3825 OBS tone. This requires that the OBS
tone of the master 9500 be "on" when the channel is active.
Master sync Mode
In this mode, all the channels at a terminal are synchronized to a high
stability source. When used end to end with itself or CCITT compatible
equipment, the frequency translation will be small, but not zero, and independent
of the E&M condition. Master oscillator stabilities available are 0.1,
2, and 5 PPM. The frequency translation error at each end of the link will
be the oscillator stability multiplied by the HF line frequency.
Master Sync with Pilot Lock
This is a variation of Mode 2 with the addition of synchronization to a
CCITT frequency reference pilot. This provides zero frequency translation
error. The Series 9500 can operate end-to-end with CCITT standard equipment
and frequencies or we can provide the master and slave pilot modules to
make a complete system. The slave unit will revert to Mode 2 upon loss
of received pilot. Master and slave modules are interchangeable in the
shelf. Two units can be used for hot standby protection with automatic
and manual switching provided.
Phase Lock Mode
This mode of operation is used in those special cases where a predictable
input-output phase characteristic is required, such as a simulcast transmit
system. In this mode, the OBS tone for the channels with phase lock must
be "on" at the master site. The same master and slave sync modules used
in Modes 2 and 3 are used.
The frequency response and envelope delay of the Series 9500 Skytrax meets
and exceeds the requirements for leased quality lines as specified in CCITT
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