Service manual

Answer: This scanner uses 16 switches set to either 1 or 0 to program the frequency. Here is the formula, with an example to work with:
Take the display and divide it into groups of 4 bits each:
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16
1 2 3 4
Group 1 is as follows:
Band MHz 1 2 3 X
VHF Lo 30-50 0 0 0 0
VHF Hi 150-172 0 0 1 120
UHF LO 450-470 0 1 0 420
UHF Mid 470-490 0 1 1 440.0025
UHF Hi 490-512 1 0 0 460.0025
Bits 1, 2, and 3 are from the column 1, 2, and 3 above. To find bit 4, do the following:
(Freq - X +10.7) / 12.8
The answer is between 3 and 5. If the answer is 4 or greater, then bit 4=0. If the answer is less than 4, bit 4=1.
Subtract either 3 or 4 from the number to leave a positive number 0 and less than 1. Multiply by 16. Enter the whole part of the number as HEX
in group 2 above.
Subtract the whole number to leave a value again greater than 0 and less than 1. Multiply by 16 again. Enter the whole part of the number as
HEX in group 3 above.
Subtract the whole number to leave a value again greater than 0 and less than 1. Multiply by 10 this time. Enter the whole part of the number as
HEX in group 4 above.
Example: 40.125 MHz
The 1 2 3 bits = 0 0 0
000x xxxx xxxx xxxx
The formula yields 3.9707031, making bit 4 = 1
0001 xxxx xxxx xxxx
Subtract 3 from 3.9707031, yielding 0.9707031
Multiply 0.9707031 by 16, yielding 15.53125, and making group 2 = 15 (1111)
0001 1111 xxxx xxxx
Subtract 15 from 15.53125, yielding 0.53125
Multiply 0.53125 by 16, yielding 8.5, making group 3 = 8 (1000)
0001 1111 1000 xxxx
Subtract 8 from 8.5, yielding 0.5
Multiply 0.5 by 10, yielding 5, and making group 4 = 5 (0101)
The coding for 40.125 MHz is 0001 1111 1000 0101.
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Product: PRO-2020 Scanner Cat. No.: 200-0112
Question: What is the frequency range?