Collins VHF-20 Documentation Page

Rockwell-Collins VHF-20 series

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5 March 2025

The Microline series of radios were targeted to the General Aviation community. 
There were two known generations of the Microline series.
The 250 and with the 251 being the later version.
The radios were rated at 10 watts compared to the VHF-20 series at 20 watts.
The 250 Version came in three versions. The standard 250, the 250E, and the 250S.
The 250 and the 250E were 720 channel radios in 25 Khz steps.
The 250E (designed for Europe) had 360 channels in 50 KHz steps.

The 251 series are drop-in replacements for the 250 series. 
The 251x series also came in 6 sub versions depend on the panel color.

The power requirements were 14 Vdc at 4.5AH in the transmit mode and 0.8 in the receive mode.
If the radio was installed in a 28 Vdc aircraft, Collins made a power convertor, the PWC-150 that would regulate the 28 Vdc to 14 Vdc.

The VHF-20 was the first generation of the commercial system after the 618M series. The VHF-20 then evolved to the VHF-21 and later into the VHF-22 version. The VIR-30, the navigation receiver also evolved more or less at the same time. There was the VIR-30 which over time, became the VIR-31 and then the VIR-32.

313n2 Control Head

Rockwell-Collins VHF Control Unit

FEATURES 	

    * Analog control for airborne communications, navigation, and DME
    * Digital binary (2x5 wire) frequency selection as per ARINC 410
    * Models available with 20 or 40 channel ILS capability (see table below)
    * Models available with frequency range from 118 or 116 TO 135,149, or 151 (see table below)
    * Models available with black knobs and either black or gray panel colors (see table below)
    * Models available with 5 or 28 Volt and red or white lighting (see table below)
    * Product improved versions (-5XX series) available with modular switch assemblies and 
      flexible printed circuit board to replace most of point-to-point wiring and seperate 
      switch wafers used in -00X models (see table below)
    * -5XX series contain internal diodes for tandem tuning (see table below)

	
SPECIFICATIONS 			
Environmental: 		RTCA paper 100-54/DO-60; RTCA paper 120-61/DO-108 	
TSO: 			C34a, C36a, C37a, C38a, C40a, C66
Size: 			2.625"H x 5.750"W x 5.00"L 	
Weight: 		1.9 lbs.
Temperature: 		-55 to 70C (operating) 	
Altitude: 		Up to 45000 feet (operating)
Operating Power: 	27.5 VDC +-10% 	
Freq. Selection: 	ARINC 410, digital binary code (2x5 wire) (313N-2D Control for Radio and Navigation)

Note: The CTL-20 is able to control ONE Collins VHF-20A series radio

Part Number 	Nav/Comm/DME Control Description:
522-2447-025 	20 ch. ILS, DME control, comm freq. range 118-135.975, black panel & knobs, 28V red lighting
522-2447-035 	20 ch. ILS, DME control, comm freq. range 116-149.975, black panel & knobs, 28V red lighting
522-2447-048 	20 ch. ILS, DME control, comm freq. range 118-135.975, black panel & knobs, 28V white lighting
522-2447-050 	20 ch. ILS, DME control, comm freq. range 116-151.975, black panel & knobs, 28V red lighting
522-2447-051 	20 ch. ILS, DME control, comm freq. range 116-151.975, black panel & knobs, 28V white lighting
522-2447-056 	20 ch. ILS, DME control, comm freq. range 116-151.975, black panel & knobs, 28V red lighting
522-2447-057 	20 ch. ILS, DME control, comm freq. range 116-151.975, gray panel, black knobs, 5V white lighting
522-2447-058 	20 ch. ILS, DME control, comm freq. range 116-151.975, black panel & knobs, 28V white lighting
522-2447-059 	20 ch. ILS, DME control, comm freq. range 116-151.975, gray panel & knobs, 28V clear lighting
522-2447-225 	40 ch. ILS, DME control, comm freq. range 118-135.975, black panel & knobs, 28V red lighting
522-2447-235 	40 ch. ILS, DME control, comm freq. range 116-149.975, black panel & knobs, 28V red lighting
522-2447-248 	40 ch. ILS, DME control, comm freq. range 118-135.975, black panel & knobs, 28V white lighting
522-2447-250 	40 ch. ILS, DME control, comm freq. range 116-151.975, black panel & knobs, 28V red lighting
522-2447-251 	40 ch. ILS, DME control, comm freq. range 118-135.975, black panel & knobs, 28V white lighting
522-2447-256 	40 ch. ILS, DME control, comm freq. range 116-151.975, black panel & knobs, 28V red lighting
522-2447-257 	40 ch. ILS, DME control, comm freq. range 116-151.975, gray panel, black knobs, 5V white lighting
522-2447-259 	40 ch. ILS, DME control, comm freq. range 116-151.975, gray panel & knobs, 28V clear lighting
522-2447-260 	40 ch. ILS, DME control, comm freq. range 118-135.975, black panel & knobs, 28V red lighting
522-2447-263 	40 ch. ILS, DME control, comm freq. range 117-135.975, black panel & knobs, 28V red lighting
522-2447-264 	40 ch. ILS, DME control, comm freq. range 116-151.975, black panel & knobs, 28V red lighting
522-2447-269 	40 ch. ILS, DME control, comm freq. range 118-135.975, black panel & knobs, 5V white lighting
522-2447-270 	40 ch. ILS, DME control, comm freq. range 116-151.975, black panel & knobs, 5V clear lighting
522-2447-271 	40 ch. ILS, DME control, comm freq. range 118-135.975, black panel & knobs, 28V white lighting
522-2447-272 	40 ch. ILS, DME control, comm freq. range 117-135.975, black panel & knobs, 5V clear lighting
522-2447-273 	40 ch. ILS, DME control, comm freq. range 116-151.975, gray panel & knobs, 5V white lighting
522-2447-556 	40 ch. ILS, DME control, comm freq. range 116-151.975, black panel & knobs, 28V red lighting 
                with product improvements as above
522-2447-557 	40 ch. ILS, DME control, comm freq. range 116-151.975, gray panel, black knobs, 5V white lighting, 
                with product improvements as above
522-2447-563 	40 ch. ILS, DME control, comm freq. range 117-135.975, black panel & knobs, 28V red lighting 
                with product improvements as above
522-2447-564 	40 ch. ILS, DME control, comm freq. range 116-151.975, black panel & knobs, 28V red lighting 
                with product improvements as above
522-2447-571 	40 ch. ILS, DME control, comm freq. range 118-135.975, black panel & knobs, 28V white lighting 
                with product improvements as above

Rockwell Collins VHF Radio series (all are transceivers)

792-6657-001    VHF-20 Older version
792-6657-002    VHF-20 Older version
792-6657-003    VHF-20 Older version
792-6657-004 	VHF-20 Older version (we have personally tested this version)

622-1879-001 	VHF-20A	117.000-135.975 frequency range with +-8 kHz IF bandpass filtering 
		and is compatible with +-8 kHz offset carrier systems 
622-1879-002 	VHF-20A 117.000-135.975 frequency range with +-15 kHz IF bandpass filtering 
		and is compatible with +-15 kHz offset carrier systems 

622-1334-001 	VHF-20B	116.000-151.975 frequency range with +-8 kHz IF bandpass filtering 
		and is compatible with +-8 kHz offset carrier systems 
622-1334-002 	VHF-20B	116.000-151.975 frequency range with +-15 kHz IF bandpass filtering 
		and is compatible with +-15 kHz offset carrier systems 

Note:		The VHF-20C is a direct replacement for the VHF-20A and has the 8.33 KHz channel spacing.
		However, you must use a new control head (CTL-22C) rather than the analog and early digital unit.

622-6389-001 	VHF-21A	720 channels with narrow selectivity, 16 watt output  
622-6389-002 	VHF-21A	720 channels with wide selectivity 
622-6389-011 	VHF-21A	760 channels with narrow selectivity 
622-6389-012 	VHF-21A	760 channels with wide selectivity 

622-6390-001	VHF-21B 
622-6390-002	VHF-21B

822-1111-001    VHF-21C Euro version with 8.33 KHz channels (118.0 to 135.975 MHz)

822-1112-001	VHF-21D replacement for the VHF-21B series and has 8.33 KHz spacing. (118-151.975 MHz)

Note: VHF-22 series require CTL-22 control heads

622-6152-001    VHF-22A 720 channels with narrow selectivity
622-6152-002    VHF-22A 720 channels with wide selectivity
622-6152-011    VHF-22A 760 channels with narrow selectivity
622-6152-012    VHF-22A 760 channels with wide selectivity
622-6152-021    VHF-22A 720 channels with narrow selectivity; with reduced VHF harmonics level
622-6152-022    VHF-22A 720 channels with wide selectivity; with reduced VHF harmonics level
622-6152-031    VHF-22A 760 channels with narrow selectivity; with reduced VHF harmonics level
622-6152-032    VHF-22A 760 channels with wide selectivity; with reduced VHF harmonics level

622-6153-001    VHF-22B With 118.000-136.975 frequency range
622-6153-002    VHF-22B With 118.000-151.975 frequency range
622-6153-021    VHF-22B With 118.000-136.975 frequency range; with reduced VHF harmonics level
622-6153-022    VHF-22B With 118.000-151.975 frequency range; with reduced VHF harmonics level

822-1113-001 	VHF-22C	Basic unit with 8.33 KHz 
822-1113-021 	VHF-22C Includes filtering for GPS as detailed above 
822-1113-023 	VHF-22C Includes filtering for GPS and reduced low frequency transmitter input audio response 

822-1114-001 	VHF-22D	 Basic unit with 8.33 KHz channel spacing
822-1114-021 	VHF-22D	Includes filtering for GPS as detailed above 
822-1114-023 	VHF-22D	Includes filtering for GPS and reduced low frequency transmitter input audio response 

622-7292-101	VHF-422A CSDB/429 Interface, 118-137 MHz, 25 khz channel spacing 
622-7292-121	VHF-422A CSDB/429 Interface, 118-137 MHz, 25 khz channel spacing, GPS interference immune 

622-7293-101 	VHF-422B CSDB/429 Interface, 118-152 MHz, 25 khz channel spacing 
622-7293-121 	VHF-422B CSDB/429 Interface, 118-152 MHz, 25 khz channel spacing, GPS interference immune 


Rockwell Collins VHF Navigation Radios (receiver)
Radio navigation system providing VOR, localizer, glideslope, and marker beacon outputs as 
well as VOR/ADF display for general aviation aircraft.  
Some units have 200 VOR/LOC channels and 40 glideslope channels. 
The VIR-30 series are compatible with standard 2-out-of-5 control units.  
Provides navigation outputs to interface with pictorial navigation systems, analog area 
navigation systems, and conventional flight control systems

VIR-30A Receiver (see http://www.seaerospace.com/collins/vir30a.htm) for more detail

622-0876-001 VOR/LOC/Glideslope/Marker Beacon Receivers 
622-0876-002 VOR/LOC/Glideslope Receivers 
622-0876-003 VOR/LOC/Marker Beacon Receivers 
622-0876-004 VOR/LOC Receiver ONLY 
622-0876-011 VOR/LOC/Glideslope/MB Receivers with rotor mod. for helicopter use 
622-0876-012 VOR/LOC/Glideslope Receivers with rotor mod. for helicopter use 
622-0876-013 VOR/LOC/MB Receivers with rotor mod. for helicopter use 
622-0876-014 VOR/LOC Receiver ONLY with rotor mod. for helicopter use 
622-0876-201 VOR/LOC/Glideslope/Marker Beacon Receivers with FM immunity mod. 
622-0876-202 VOR/LOC/Glideslope Receivers with FM immunity mod. 
622-0876-203 VOR/LOC/Marker Beacon Receivers with FM immunity mod. 
622-0876-204 VOR/LOC Receiver ONLY with FM immunity mod. 
622-0876-211 VOR/LOC/Glideslope/MB Receivers with rotor mod. for helicopter use and FM immunity mod. 
622-0876-212 VOR/LOC/Glideslope Receivers with rotor mod. for helicopter use and FM immunity mod. 
622-0876-213 VOR/LOC/MB Receivers with rotor mod. for helicopter use and FM immunity mod. 
622-0876-214 VOR/LOC Receiver ONLY with rotor mod. for helicopter use and FM immunity mod 






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