Picture of product VHF-21C

Part #: 822-1111-001

Model: VHF-21C


Collins Aerospace


8.33 VHF Comm

Part Number :


Image shown is VHF-22A due to similarities in appearance between units.

  • Proline II remote-mounted, multichannel VHF voice transceiver providing AM voice communications in the frequency range from 118.000-135.975 in 8.33 kHz increments
  • Intended as direct replacement for VHF-20 and VHF-20A units
  • Can be used with Proline II CTL-22C control
  • Accept either 2-out-of-5 parallel or RS-422A serial digital tuning data from frequency control unit
Weight: 4.7 lbs. Dimensions: 3.75"W x 3.36"H x 14.0"L
FAA TSO: C37c, C38c EUROCAE: ED-23, ED-24
FCC: Part 15, Part 87 Environmental: DO-160A, categories /A2E1/B/JY/ EXXXXXXZ/BZ/AZA, EUROCAE ED-14A
Temperature: -54 to 70C (operational) Altitude: 70000 ft.
Frequency Stability: +-0.0015% Frequency control: CSDB or ARINC 2-out-of-5
Power Requirements: Receive- 0.5A (14W) at 27.5 VDC; Transmit- 6.0A (165W) at 27.5 VDC Output Power: 16W minimum into a 52 ohm resitive load
Modulation: 85% modulation capability with less than 15% distortion; 95% limiting Sidetone: 100 mW into 600 ohm load
Duty cycle: 1-minute transmit; 4-minute receive Receiver Sensitivity: 3 uV for 6dB (s+n)/n
Receiver Selectivity: Typical 6dB at +-8 kHz, 60dB at +-17 kHz AGC: 3dB max variation, 5uV to 1V
Part NumberVHF Communications Transceiver Description:
822-1111-001 See details above


- 8.33 VHF Comm
Price Condition Status

Click on a question below to see the answer. If you have a question about this model that is not answered below, please contact questions@seaerospace.com

In relation to NE (New) parts, many OEMs change their prices and availability without any notice to dealers or the industry. Therefore, through the REQUEST or RFQ indication, we ask that customers contact us for the most accurate price and availability.

In relation to SV & OH parts, the used parts aftermarket in the aviation industry is not an infinite supply. It is a dynamic, constantly changing market that is significantly affected by and susceptible to highs and lows in supply and demand. Therefore, although we attempt to, at times, we are unable to predict the exact moment when an item may be available. Once again, through the REQUEST or RFQ indication on our website, we ask that customers contact us for the most current and accurate price and availability.

8.33 refers to the kilohertz (kHz) channel spacing for VHF communications radios required in certain types of airspace. Normal channel spacing for VHF comm radios is 25 kHz. Currently, 8.33 kHz channel spacing is only required above FL195 (19500 ft.) in the ICAO European region as of 15 March 2007.

8.33 channel spacing was introduced and implemented to help reduce VHF communication overlap and congestion in high traffic areas in Europe. With dividing 25 kHz by 3 (thus 8.33), many new communication frequencies were created. Only very specific radio equipment is capable of channeling, transmitting, and receiving in 8.33 kHz increments. Some of the more popular systems include the Rockwell Collins VHF-21/22/422/C/D and Bendix/King KX-165A (-0201), KY-196B. The Garmin GNS-430/530 series systems are capable of 8.33 also.

The VHF-21C will directly replace the VHF-20A (i.e. no rack or connector change). However, the original controls for the VHF-20A (ex. 313N-5A, CTL-20) are not capable of 8.33 kHz channeling. Therefore, you must replace the original control with the CTL-22C.