Radio Shack Pro-60 - Scanner Operation Basics; Setting Volume and Squelch; Searching for Frequencies

Referenee Frequeney Ose. Alignment
Control Setting
Test Instrument Connection
Adjust Result
OFFNOLUME control: ON. Connect the frequency counter
TC102
Adjust TC102 so the frequency
SQUELCH control: CCW. to TP101. See Figure 4. is 1123.200000 MHz ± 200 Hz.
Select channel 1.
Unit
TP101
Frequenc. Counter
UnderTest
,J,.
Figure 4
Note: If no frequency counters capable of measuring 1200 MHz are available, use a frequency counter capable of
measuring 20 MHz. Follow the instructions below so the frequency counter can do an appropriate adjustment.
1. The frequency counter for measurement should be accurate within 1 Hz.
2. Be sure a 2 pF capacitor is connected to the end of the cable of the signal line. The unit would be destroyed if
you did not use this capacitor.
If a capacitor other than the 2 pF capacitor is used, or if the capacitor is connected anywhere other than the
end of the measurement cabie, correct measurement will never be obtained because of the effects on the oscil-
lator.
3. Be sure the coaxial cable for measurement is as short as possible (shorter than 1 meter) to avoid stray capaci-
tance effects.
4. Test point locations and adjustment frequency range are as follows:
Pin 15 of IC101 and C188 (10 pF) are connected to a through hole, as shown in "Alignment and Test
Points"
(Page 9). Connect a 2 pF capacitor at a through hole pattern location and then adjust TC102 so that the frequency
range is 12.799937 MHz
±2 Hz.
2 pF
Unit
0-
H
Frequency Counter
Under Test
,J,.
Figure 5
NFM/AM Diseriminator Coi! Alignment
Control Setting Test Instrument Connection Adjust Result
OFFNOLUME control: ON. Connect the signal generator T301
Set the signal generator
SQUELCH controt CCW. to the Ant. connector and the frequency to 512 MHz, 100
JlV
Select channel 1. DC SSVM to TP301. output (no mod.), and adjust
See Figure 6. T301 to 1±0.1 volt on the DC
SSVM.
-11-