Codan 8550

8550 series automatic tuning antenna system

New Release in 5/1986

The 8550 series automatic tuning antenna systems

comprise the 8555 and 8556 whips (2.5 metres)— 

covering the operating frequency range of 2 to

11 MHz and 3.5 to 18 MHz respectively—the 8551

antenna control unit, and the 8552 tuner-controller.


The system, using a microprocessor controlled

stepper motor to provide continuous tuning over the

frequency range of the whip, has been designed for

multi-frequency land mobile applications.


Typical tuning time from one channel frequency to another 6 seconds.


On installation, no further tuning or technician

programming Is required—the system being fully automatic.


The type 8555 and 8558 automatic tuning whip

antennas are identical in physical dimensions

differing only in their operating frequency range.

The whips are centre loaded and are constructed

from anodised aluminum alloy tubing with a

waterproof lower section housing the control

devices, and a mid section spring knuckle.


The 8551 antenna control unit is the interface between

the whip antenna and transceiver and contains the

microprocessor and controlling electronics. As there

are no external operator controls, the unit can be

installed in any convenient position within the

vehicle. The 8551 can be used for either single or

dual whip installations.


The 8552 tuner-controller will be available for those

installations where transceivers other than the

Codan transceiver type 8525 series are used.


Frequency range

8555  2 to ll MHz         Moonraker model AT17

8556   3.5 to 18 MHz   Moonraker model AT318

Channel capacity

Continuously variable

Power rating

120 watts PEP

Power consumption

100 mA—static

2A—tuning 3ypica{)

(1 2V DC nominal—supplied from transceiver)


Anti-vibration mount ½” Whitworth stainless steel stud, 30 mm long, supplied with nut and washers

Control and coaxial cable

Type 8555 and 8556 whip: 6 metres tong

Type 8551 Control unit: 2 metres long

Input impedance 50 ohms: VSWR 1.5:1

Size and Weight

8555 and 8556

2.5  metres long X 80 mm dia: 3 kg


230 mm W X 119mm  D X 58mm H 0.7Kg

(includes mounting bracket)

Sketched outline of the 8550-Circa 1986