Kr86 Pilots Guide 352vu

BENDIX KING KR86

ADF

PILOT’S GUIDE

This manual has been compiled by RAAC based on following reference document: ----published by: ----FOR USE BY RAAC- ONLY !!!

Antwerp, Revision 1.0, September 2005

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EQUIPMENT DESCRIPTION.

Figure 1. Operating Controls. The Bendix King KR86 ADF is a -mounted, digitally tuned automatic direction finder. It is designed to provide continuous 1 kHz digital tuning in the frequency range of 200 kHz to 1,799 kHz and eliminates the need for mechanical band switching. The system is comprised of a receiver, a built-in bearing indicator and a combined loop and sense antenna. Operating controls and displays for the Bendix King KR86 ADF are shown in Figure 1. The audio systems used in conjunction with this radio for speaker-phone selection are shown and described in other RAAC-avionics brochures. The Bendix King KR86 ADF can be used for position plotting and homing procedures, and for aural reception of amplitude-modulated (AM) signals. With the function selector knob at ADF, the Bendix King KR86 ADF provides a visual indication, on the bearing indicator, of the bearing to the transmitting station relative to the nose of the airplane. This is done by combining signals from the sense antenna with signals from the loop antenna. With the function selector knob at ANT, the Bendix King KR86 ADF uses only the sense antenna and operates as a conventional low-frequency receiver. With the function selector knob at BFO, a 1000 Hz tone beat frequency oscillator is activated, permitting coded identifier of stations transmitting keyed CW signals (Morse code) to be heard. The Bendix King KR86 ADF is designed to receive transmission from the following radio facilities: commercial AM broadcast stations, lowfrequency range stations, non-directional radio beacons, ILS com locators.

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OPERATING INSTRUCTIONS. Turn-on. Rotate the ON/OFF/VOL knob [3] clockwise from the detented “OFF” position. The unit will be activated and will be ready to operate. Rotation of this control also adjusts audio volume. The KR 86 has “audio muting” which causes the audio output to be muted unless the receiver is locked on a valid station. Frequency Selection. The frequency to which the ADF is tuned is displayed in the window [1] at all times. The frequency is selected using the frequency select knobs [2] which may be rotated either clockwise or counterclockwise. The most left one selects 100-kHz increments of receiver frequency; the middle one selects 10-kHz increments; and the right one selects 1-kHz increments. Operating Modes. The ADF mode is selected when the operating mode selector [4] is set in the left “ADF” position. ADF activates the bearing pointer [7] of the KR86 indicator, causing it to move without hesitation to point in the direction of the station relative to the aircraft heading. The com card [6] on the KR86 indicator may be rotated as desired by using the heading/test knob [5] to indicate either relative, magnetic, or true heading of aircraft if correctly aligned with the lubber line [8]. Antenna (ANT) mode is selected when the operating mode selector [4] is set in the middle “ANT” position. The KR86 will behave as a standard communication receiver using only the sense antenna. ANT provides improved audio reception from the station tuned and is usually used for identification. The bearing pointer [7] in the KR86 indicator will be de-activated and will remain steady during ANT reception. Some stations are unmodulated and use an interrupted carrier for identification purposes. The BFO mode, activated when operating mode selector [4] is set in the right “BFO” position, permits the carrier wave and the associated Morse code identifier broadcast on the carrier wave to be heard. ADF Test (PRE-FLIGHT OR IN-FLIGHT) Push the heading/test knob [5] to test bearing reliability. While pushed in TEST, slews the bearing pointer [7] clockwise; when released, if bearing is reliable, the bearing pointer [7] should move without hesitation back to the original bearing position. Excessive sluggishness, wavering or reversals indicate a signal that is too weak or a system malfunction.

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Erroneous ADF Bearings Due to Radio Frequency Phenomena. Station Overlap Occasionally the same frequency may be allocated to more than one station in an area. Certain conditions, such as Night Effect, may cause signals from such stations to overlap. This should be taken into consideration when using AM broadcast stations for navigation. Sunspots and atmospheric phenomena may occasionally distort reception so that signals from two stations on the same frequency will overlap. For this reason it is always wise to make positive identification of the station being tuned, by switching the function selector to ANT and listening for station call letters. Electrical Storms In the vicinity of electrical storms, an ADF Indicator pointer tends to swing from the station tuned toward the electrical discharges. Location of the storm can be useful information, but the erratic behavior of the pointer should be taken into . Night Effect This is a disturbance particularly strong just after sunset and just after dawn. An ADF indicator pointer may swing erratically at these times. If possible, tune to the most powerful station at the lowest frequency. If this is not possible, take the average of pointer oscillations to determine relative station bearing. Mountain Effect Radio waves reflecting from the surface of mountains may cause the pointer to fluctuate or show an erroneous bearing. This should be taken into when taking bearings over mountainous terrain. Coastal Refraction Radio waves may be refracted when ing from land to sea or when moving parallel to the coastline. This should be taken into when operating near coastal areas.

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SPECIFICATIONS.

FEATURES • • • •

mount ADF receiver with built-in ADF indicator Digitally tuned solid state receiver Tuning speed is typically 0.1 second from time frequency is selected Typically used with KA-42B combined loop/sense antenna for easy 2-piece installation

SPECIFICATIONS Size:

6.25"W x 2.60"H x 9.05"L

Weight:

3.1 lbs.

Design:

All solid state, convection and radiation cooled

Applicable Documents:

FAA Minimum Operation Characteristics (MOC) RTCA Document DO-137

Frequency Range:

200KHz to 1799KHz in 1 KHz increments

Receiver Selectivity:

6dB bandwidth: +-1.0 KHz min ; 55dB bandwidth: +-6 KHz max

Bearing Accuracy:

+ 3 degrees from 70 uV/m to 0.5 V/m RF input signal level

Power Requirements:

13.75 VDC at 0.5 amps (ADF Mode) 0.35 amps (ANT Mode)

Temperature Range:

-15 to +55C (continuous)

Altitude Range:

Up to 30,000 feet

Receiver Senstivity:

100uV/m max for s+n/n = 6dB (ADF mode)

Indicator Speed:

6 seconds typical with indicator 175 deg. off bearing and 70 uv/m to 0.5 v/m rf input signal level

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