Part #: 822-1111-001

Model: VHF-21C

Collins Aerospace - 8.33 VHF Comm
product image
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 Delivery
$3,495.00 OH OUTRIGHT

SEA Repair Capabilities: No

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

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.
Southeast Aerospace exchanges are based on the return of an undamaged, economically repairable core unit with identical part number as the unit shipped to the customer. An "economically repairable" core is defined as one where the cost to repair/overhaul (or Repair Cap) does not exceed 80% of the original SV/OH exchange price billed. Should the Repair Cap exceed 80%, the customer will be billed the additional amount. In the event this amount exceeds the Outright Price for the unit, the customer would only be billed the difference between the Outright Price and SV/OH Exchange Price with the core returned as-is to the customer.

Here is an example of such a transaction:

$1000 Exchange Price charged to customer
$1000 x .8 = $800 Maximum Allowable core repair charge or Repair Cap

$2000 Cost to repair core unit
- $800 Less Core repair cap
$1200 Additional billing amount.

2200.00 Total Cost of transaction

Please Note:
SEA offers exchange on new items as well. However, repair cap as indicated above is still based on SV/OH exchange price.

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.