2-8 888-2463-001 3/6/08
WARNING: Disconnect primary power prior to servicing.
Diamond Series™
Section 2 Installation
Tuning probes, used for fine matcher construction, are provided with the installation kit.
Four probes are installed at 1/8 wavelength intervals along the length of a short section
of line. The distance for 1/8 wavelength is calculated using the formula: spacing (inches)
= 1476/F
MHz
. Where F
MHz
= center frequency of the channel. When constructing a fine
matcher, drill four holes in the outer conductor of the line and solder nuts over the holes
to provide threads for adjusting the depth of the probe.
The probes provide adjustable shunt capacity every 90 electrical degrees and are used to
cancel out reflections that occur a short distance down the line toward the load. A fine
matcher is often installed on the output of each PA Cabinet (after the directional coupler
line section) and possibly at the output of the filter.
The fine matcher must be within 10 wavelengths of the unwanted reflection. If the
distance is greater than 10 wavelengths, the bandwidth of the correction will be too
narrow. Also, the correction will be unstable as the temperature of the line changes.
2.6 Inter-Cabinet Wiring
A cable tray is built into the top of the PA Cabinet to facilitate inter-cabinet wiring.
Install the serial, parallel and PA Cabinet RF Drive cables in this tray. It is accessed by
removing the machine screws that hold the cover down. The serial CAN bus
termination is also in this tray at the top of the PA Cabinet furthest from the Control
Cabinet.
NOTE:
The cabinet inter-connect cables are bundled and shipped inside the cable trays
on top of the individual cabinets. One end should already be connected, while the
open end of the cable has the proper connection point printed on the heatshrink.
Refer to the "Can System Block Diagram" in Section 200 of the schematic package for
the following connections:
• CAN BUS Cable - The CAN bus cable connects the Control Cabinet I/O J8 to J4 of
the first PA Cabinet. For subsequent PA Cabinets, J6 will connect to J4 of the next
connected PA Cabinet. The last PA Cabinet in the daisy-chain must be terminated
with a 120 ohm resistor (this should already be installed from the factory). J4 and J6
are located in the cable tray on top of the PA Cabinet. Remove the machine screws to
gain access. Looking from the back of the cabinet, J4 is the serial connector on the
right with J6 on the left.
• Parallel Control Cable - A ribbon cable connects from the Control Cabinet J9 to J5 in
the first PA Cabinet. For subsequent PA Cabinets, J7 will connect to J5 of the next
connected PA Cabinet. Looking from the back of the cabinet, J5 is the parallel con-
nector on the right with J7 on the left.
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