User Manual

Mission Valley Radio Repeater Equipment + Upgrade
User/Maintenance Handbook
Handbook No. 50-078021HBKM Page 23 of 85
3.8.3 VHF/ UHF Programming Procedure
The operating frequency for each channel in the Cell Enhancer is programmed by 16 DIL (Dual In
Line) switches. The programming switches are mounted in the Channel Control Modules which are
located beside the channel modules in the module racking. The Channel Selectivity Modules are
connected to the Channel Control Module via 25 way ribbon cables.
Switch 16 is at the far left of the line of switches leading down to Switch 1 at the far right of the line.
Adjacent to the DIL switches for each channel is a toggle switch to turn on and off individual channels
as required. A green LED indicates the DC ON status of each channel.
A red LED shows the alarm condition for each channel. An illuminated alarm LED indicates that the
synthesiser has not achieved phase lock and that the module is disabled. There is a problem which
requires investigation, often a frequency programmed outside the operating frequency range.
The following information is necessary before attempting the programming procedure.
1) operating frequency
2) synthesiser channel spacing (step size)
3) synthesiser offset (IF)
Check that the required frequency falls within the operational frequency limits of the Cell Enhancer.
For each channel required, subtract the synthesiser offset from the required operating frequency and
record the resulting local oscillator frequency.
Divide each local oscillator frequency by the channel spacing and check that the result is an integer
(i.e.: no remainder).
If the synthesiser division ratio is not an integer value, check the required operational frequency and
repeat the calculation checking for mistakes.
Convert the required local oscillator frequency to synthesiser programming switch state patterns
according to the following table.
Switch number Synthesiser offset added when switch in UP position
1 +12.5kHz
2 +25kHz
3 +50kHz
4 +100kHz
5 +200kHz
6 +400kHz
7 +800kHz
8 +1.6MHz
9 +3.2MHz
10 +6.4MHz
11 +12.8MHz
12 +25.6MHz
13 +51.2MHz
14 +102.4MHz
15 +204.8MHz
16 +409.6MHz