VHF/UHF Airborne Blade Antenna
30 to 88 MHz, 108 to 174 MHz and 225 to 512 MHz
The 21-50-44 is a tri band VHF/UHF communications antenna intended for use on high speed aircraft, suitable for use with multi-mode radios such as AN/ARC-210. Its construction is from precision machined aluminium alloy with high strength glass/epoxy inserts. Having a low profile diamond shape raked blade structure minimizes drag for high speed applications and presents a low Radar Cross Section (RCS). The aluminium structure also lends itself to the application of certain types of ‘stealth’ radar absorbing material.
The electrical design comprises a UHF sleeved unipole, the upper element of which acts as a "choke" enabling a capacitive horizontal rod with selective resistive matching to operate as a top loaded VHF monopole, decoupled from the UHF section. A small in-line passive matching unit (part number 21-80-50), supplied with the antenna matches VSWR in the low VHF band.
Designed and constructed to meet MIL-STD-810C environmental conditions, the 21-50-44 is a drop-on footprint replacement for UHF blade type AT-256, having a single N-type Female connector. The antenna is normally finished in lusterless grey urethane paint.
30 - 88 MHz
108 - 174 MHz
225 - 512 MHz
30 - 88 MHz -23 dBi rising to -8 dBi
108 - 174 MHz -5 dBi min +1 dBi average
225 - 512 MHz +1 dBi average
30 - 88 MHz ≤ 2.5:1
108 - 117 MHz ≤ 3.0:1
118 - 174 MHz ≤ 2.5:1
225 - 450 MHz ≤ 2.5:1
451 - 512 MHz ≤ 5.0:1
|Impedance (nominal)||50 Ohms|
|Power||25 Watts CW|
|Radiation Pattern||Omni directional in azimuth|
|Antenna RF Connector||N Female|
|Antenna Shell Type||Diamond shaped aluminum alloy with fiberglass inserts|
|Height||12.42 inches (315 mm)|
|Weight||3.5 lbs (1.59kg) (including 21-80-50 matching unit)|
|Base Plate Shape||Diamond shape drilled to replace AT-256|
|Fixing Holes||6 x Ø 0.200 inches (5mm) holes, counter sunk at 100° Ø 0.39 inches (9.9mm)|
- Matching Unit Urethane Lusterless Black
- Antenna - Urethane Lusterless Grey
- Other finish options are available.
- Please specify finish required when ordering.