User's Manual

Weehawken Tunnel VHF Repeater System
User/Maintenance Handbook
Handbook N.-Weehawken_VHF Issue No:-A Date:-05/08/05
Page:-
61 of 75
7.11.4 25kHz step size switch functions
Switch
Number
Synthesiser offset added when switch in UP
position
1 +25kHz
2 +50kHz
3 +100kHz
4 +200kHz
5 +400kHz
6 +800kHz
7 +1.6MHz
8 +3.2MHz
9 +6.4MHz
10 +12.8MHz
11 +25.6MHz
12 +51.2MHz
13 +102.4MHz
14 +204.8MHz
15 +409.6MHz
16 +819.2MHz
7.11.5 Programming Example
Frequency required: 454.000MHz
Channel spacing: 12.5kHz
Synthesiser offset: -21.4MHz
The Local Oscillator frequency is therefore:
454.000 – 21.4 = 432.600MHz
Dividing the LO frequency by the channel spacing of 0.0125MHz:
432.600 = 34608
0.0125
This is an integer value, therefore it is OK to proceed.
Local Oscillator
Frequency
Switch settings
16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
432.600 MHz
1 0 0 0 0 1 1 1 0 0 1 1 0 0 0 0
Switch setting: 0 = switch DOWN (ON, frequency ignored )
1 = switch UP (OFF, frequency added )