Moseley PCL-600, User Manual

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1-8 System Characteristics
Moseley PCL 6000 Document No. 602-13375-01 Rev.B
Multichannel Operation (Option)
The Channel Control board is pre-programmed to select the transmitter carrier frequency by
controlling the FMO/synthesizer (in the RF module) and the modulation compensation circuitry
(located on board). This board has facilities for over-ride of the pre-programmed channel
frequencies (Channel 0 operation). Remote control of the channel selection is also provided on
this board through access to the back panel. Channel selection and display is accessed by the
user through the front panel. The Channel Control board connects to the RF module via a 25-pin
D ribbon cable. The RF module must be compatible for multichannel operation. Please contact
the factory for field retrofit of the system.
1.4.2
PCL6020, PCL6030, PCL6060 Receivers
The PCL6000 System has three receivers which are designed for different RF environments. The
PCL6060 and PCL6030 are triple-conversion receivers which provide maximum out-of-band and
adjacent channel protection. The PCL6060 exhibits superior front end performance in the
presence of extremely strong RF fields, as it uses modules from the time-proven Moseley
PCL606 STL. The PCL6020 is a dual-conversion receiver that provides maximum performance in
all but the most demanding environments. Both systems are switchable to support mono or
composite operation. The receivers are modular in construction and operation, and the system
description given below follows the signal flow through the various modules.
Refer to Figures 1-2a/b, 1-3a/b, and 1-4a/b, Receiver Block and Level Diagrams. Assembly
drawings and schematics for the complete receiver systems and for their modules are located in
Section 7.
Preselector/Preamplifier (950 MHz, PCL6020/6030)
The Preselector/Preamplifier is located in the RF module. The antenna input signal is first passed
through the preselector filter, which is a pcb-mounted helical bandpass filter with very low
insertion loss. The output of the preselector filter is fed to the preamplifier providing low-noise
gain. The postselector filter provides further filtering as well as image noise rejection.
Preselector Filter (950 MHz, PCL6060)
The antenna input signal is first passed through the Preselector Filter, which is a five-element,
interdigital bandpass filter with a 20 MHz bandwidth and maximum insertion loss of 1.5 db. This
filter has superior rejection due to its mechanical implementation.
Preamp/1st Mixer (950 MHz, PCL6060)
The output of the Preselector Filter is fed to the Preamp/1st Mixer module. This module
incorporates an adjustable PIN diode attenuator for user-adjustable front end protection. The low-
noise, high-intercept point preamplifier is followed by the image noise filter. The 1st Mixer down-
converts the carrier to the first IF (70 MHz) by mixing with the 1st LO and is buffered for
transmission to the Double Converter/LO3 module.
Preselector Filter (220–450 MHz)
The antenna input signal is first passed through the Preselector Filter, which is a three-element,
helical bandpass filter with an 8 MHz bandwidth and maximum insertion loss of 1.5 db. This filter
has superior rejection due to its mechanical implementation.
Preselector Filter (1.7 GHz)
The antenna input signal is first passed through the Preselector Filter, which is a five-element,
interdigital bandpass filter with a 20 MHz bandwidth and maximum insertion loss of 1.5 db. This
filter has superior rejection due to its mechanical implementation.