Lectrosonics SIXPACK - Manual (Page 4)

SIXPACK
General Technical Description
The SIXPACK system is a high performance, 6-chan­
nel receiver multicoupler designed primarily for motion
picture and television production in the studio and
in the field. The design provides antenna and power
distribution for up to six Lectrosonics compact diversity
receivers, such as the UCR411A model. Other receiv­
ers built in the same housing will also work provided
the frequency is within the bandwidth of the filters.
The SIXPACK consists of three sub-systems:
• Housing assembly with gel-cell batteries
• Master RF/power distribution module
• Slave RF distribution module
The SIXPACK can be used with all UHF diversity
compact receivers, such as the UCR411a and several
earlier models with the same size housing, provided
that the frequency range of the receiver falls within the
filter passband of the multicoupler modules.
Options include various antennas, power supplies and
battery chargers. The mechanical assembly is covered
with a padded, naugahyde cover with reinforced, zip­
pered and hinged front and rear panels. The machined
aluminum housing includes a strap handle bolted
directly to the top panel.
Problems such as interaction of receivers, inter-
modulation and desensitization have been eliminated
with the use of proven design principles in the active
antenna multicouplers. The front end design places RF
filtering before gain to minimize intermodulation (IM)
products and prevent overload. Two transmission line
ceramic resonators at the input provide filtering with a
230 MHz bandwidth.
Following the resonators is a low noise, low gain RF
amplifier to compensate for splitter losses in the stage
that follows. A precision splitter/isolator divides the RF
signal into six isolated signals to prevent spurious RF
coupling between receivers. The splitter/isolator is also
termination independent, which prevents mismatched
or disconnected RF outputs from affecting the other
receivers.
Power can be supplied to the distribution module from
three different sources:
• The built-in battery pack
• External DC
• External AC from the charger
Lead-acid gel-cell batteries were selected for their
recharge characteristics and reliability under extreme
conditions. The batteries are also highly resistant to
damage caused by prolonged deep discharge. The
batteries are connected in series to provide 12 VDC
(nominal) power.
The primary source is the gel-cell battery pack built
into the bottom of the assembly. Secondly, power may
also be provided through an external DC power source
of 12 to 16 VDC via the 4-pin XLR jack on the master
module. When an external DC source is connected,
an internal relay automatically disconnects the internal
battery pack. If that DC source fails or is disconnected,
the system automatically reverts to the internal batter­
ies. AC power can be provided by the CH80 charger to
operate the system and charge the internal batteries
simultaneously. All power circuits in the distribution
module are independently protected by internal auto-
reset fuses. If the fuse on one receiver opens for any
reason, the other receivers will continue to operate.
Figure 1 - SIXPACK Block Diagram
LECTROSONICS, INC. 4