Print Date 12/05/15 Page 6 of 32 S7600-00MA-08
Each Amplifier also has its own front panel ‘mute’ switch, which is mechanically interlocked so that it
has to be operated before the module can be removed. All other signal, 50V dc supply and control
connectors are at the rear of the unit. The control connectors go to one of two independent internal
Transmitter control buses.
Each control bus has its own RS485 data bus, which is used to carry the monitored serial information
from the amplifier to the E2023 Controller. Each bus also has its own power level control line, derived
from the E2025 Combiner Unit, to set the power level of each amplifier module and thus the final
transmitter output power.
Various versions of the 300W Amplifier Module may be supplied. These versions have slightly
different internal circuitry. They are however interchangeable, but to maximise output power, all
modules should ideally be of the same version.
1.1.2 : E2088/E2322 Power Supply Module
Any given Transmitter can only accept either E2088 or E2322 modules, not both
Two of these are provided on the S76005 and S7601, with four on the S7602 (two more on the /P
options). The modules are equally grouped into two supplies ’A’ and ‘B’, with independent mains
supply connectors to enable operation from dual mains supplies. The 500W S76005 may optionally be
supplied with just one module/connector. The E2088/E2322 modules in each group are current OR’d
together. Thus, on the /P option, where the extra module is fitted, the current lost when any single
module in the group fails, can still be supplied by the remaining module(s) in the group.
The ‘A’ supply provides a supply bus to the one, two or four E2021 Amplifier Modules on the right
hand ‘A’ side of the transmitter. The ‘B’ supply provides a separate bus to the one, two or four
Amplifier Modules on the left hand ‘B’ side. Single units requiring power (E2023, E2024 and E2025)
and both cooling fans are supplied from both supply buses.
All supplies are switched via a single front panel safety switch. The switch can be padlocked in the ‘off’
position to ensure that the transmitter remains off whilst work is being carried out at the antenna etc.
Each E2088/E2322 Power Supply Module has its own forced air cooling, output control and monitoring
circuitry and generates a regulated 50V to 53V dc supply. Apart from on the single module 500W
variant, failure of a single Power Supply Module leaves the Transmitter still operating but with a 6dB
reduction in output power. As with the Amplifier Modules, each E2088/E2322 Power Supply module
can be removed or replaced, within seconds, whilst the Transmitter is operating. Red/green fault
displays, relatively low weight and small size again feature.
50-53Vdc outputs for each Amplifier, for all the low power single units and mains supplies for each
Exciter are provided via separate fuses at the rear of the Transmitter. The Power Supply monitor
connectors go to one of two independent internal Transmitter control buses and hence to the E2023
Controller.
1.1.3 : E2023 Transmitter Controller Unit
This single unit provides comprehensive monitoring of the forward power, current and temperature of
each E2021 Amplifier Module and of the final output forward power, reverse power and temperature
via the E2025 Combiner Unit. It also monitors the E2088/E2322 Power Supply Modules. In the
situation where dual drive automatic changeover or automatic power level control is used, this unit
provides the necessary control. Remote control and monitoring of the Transmitter can also be
provided via this unit using parallel or serial data.
The Control Unit is microprocessor based with a back illuminated, high contrast 4 line by 20 character
display and separate red/green ‘System Normal’ indicator. A robust, sealed membrane keypad is
provided with a sounder to indicate correct key entry. The rear of the unit has separate connectors for
the two independent internal Transmitter control buses, connectors to monitor and control one or two
Exciters, a connector for power level control and a connector for parallel monitoring. An RS232
monitor/control port is provided on the front panel (E2023-01/02) with an additional TCP/IP
monitor/control port on the rear (E2023-02 only). An RS232 monitor/control port is provided on the
