Radio Shack 20-423 owner manual Specifications, Channels of Operation

ˆSpecifications

Frequency Coverage:
Ham	29–30 MHz (5.0 kHz Steps)
VHF Lo	30–50 MHz (5.0 kHz Steps)
Ham	50–54 MHz (5.0 kHz Steps)
Air	108–136.9875 MHz (12.5 kHz Steps)
Government	137–144 MHz (5 kHz Steps)
Ham	144–148 MHz (5 kHz Steps)
VHF Hi	148–174 MHz (5 kHz Steps)
Ham/Government	380–450 MHz (12.5 kHz Steps)
UHF Lo	450–470 MHz (12.5 kHz Steps)
UHF Hi (T)	470–512 MHz (12.5 kHz Steps)
Channels of Operation	200 Channels and 20 Monitor Memories
Sensitivity (20 dB...............................................................................................................S/N):	0.5 ∝V
29–54 MHz
108–136.9875 MHz	1.0 ∝V
137–174 MHz	0.5 ∝V
380–512 MHz	0.7 ∝V
Selectivity:
±10 kHz	–6 dB
±18 kHz	–50 dB
Spurious Rejection	50 dB (FM at 154 MHz)
Scanning Rate	Up to 25 Channels/Second
Search Rate	Up to 50 Steps/Second
Delay Time	2 Seconds
Intermediate Frequencies (IF):
1st	10.7 MHz
2nd	455 kHz
IF Interference Ratio (10.7 MHz)	70 dB at 154 MHz
Squelch Sensitivity:	Less than 0.5 ∝V
Threshold
Tight (FM)	(S+N)/N 25 dB
Tight (AM)	(S+N)/N 20 dB
Antenna impedance	50 Ohms

30 Specifications