User's Guide

DANIELS
ELECTRONICS LTD
TM
CI-PM-3 Paging Modulator Instruction Manual 3-7
The delay calculations for any paging transmitter site in a multiple-transmitter system, with
distances measured from the site of interest back to the BASE TX, becomes:
Delay
(Site of Interest)
=(d
(Furthest Site)
(km) - d
(Site of Interest)
(km)) × 3.33 µ sec
or
=(d
(Furthest Site)
(mi) - d
(Site of Interest)
(mi)) × 5.37 µ sec
To set the delay value: Once the required delay has been calculated for a particular paging site, refer
to Table 4-3 delay settings:
a) Locate the DELAY (µsec) value which is closest to the calculated value.
b) Set surface mount jumpers JU31, JU32, JU33, and JU35 according Table 4-3 in section 4.3.
Data Delay Adjust: To set delay values other than those listed in Table 4-3:
1. Set the oscilloscope for 1.0 V/Div (vertical) and 0.5 µs/Div (horizontal). Select channel 1 as
trigger input and set Trigger Slope to positive.
2. Monitor the test data signal at TP9 on channel 1 of the oscilloscope and the output signal at
TP5 on channel 2.
3. Adjust the oscilloscope for maximum horizontal display of the distance between the signals’
leading edges. Adjust tuning capacitor C55 until the output signal’s leading edge on channel 2
is delayed from the input signal’s leading edge on channel 1 by the desired delay amount.
Example: To set a delay of 44 µsec:
i) Set oscilloscope horizontal resolution to 5 µsec/div.
ii) Install surface mount jumpers JU31B, JU32A, JU33A and JU35E (refer to Table 4-3).
iii) Monitor TP9 on channel 1 of the oscilloscope. Monitor TP5 on channel 2 of the oscilloscope.
Adjust C55 for 8.8 horizontal divisions between the signals’ leading edges
(8.8✕5 µsec = 44 µsec delay).