Quantcast
AUTOMATIC DIRECTION FINDER (ADF)

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
The barometric switch in the RAWS auto- matically resets its altitude reference pressure to ground level before flight. When 700 feet above takeoff altitude has been reached, the switch actuates and changes the RAWS reliability circuit. At this point, the radar altimeter reliability signal is inhibited. This prevents nuisance warnings when the aircraft is flying above the operating range of the switch. AUTOMATIC DIRECTION FINDER (ADF) The Direction Finder Set, AN/ARN-83, is known as a low frequency automatic direction finder (LF/ADF). This system is a radio navigational aid that operates in the low-to-medium-frequency range. It continuously indicates the bearing to a selected radio station, acts as a manual direction finder, and as a conventional low-frequency radio receiver for voice and unmodulated transmissions. The LF/ADF is sometimes referred to as a radio compass. Major Components The AN/ARN-83 direction finder set consists of four major components. The y are the R-1391/ ARN-83 receiver, the C-6899/ARN-83 control panel, the AS-1863/ARN-83 loop antenna, and the ADF sense antenna. RADIO RECEIVER R-1391/ARN-83.— The radio receiver is remotely controlled from the ADF control. It does all processing of signals received by the loop and sense antennae and sends bearing information to the navigation indicator group. DIRECTION FINDER CONTROL PANEL C-6899/ARN-83.— The control panel controls all functions of the system (fig. 2-11). Selection of the three modes of operation is accomplished here. Manual control of the loop antenna is done using the LOOP knob. The tune knob tunes the receiver for the Figure 2-11-Direction finder control panel C-6889/ARN-83. station, and it is visually indicated through the frequency dial. The tuning meter indicates the strength of the receiver signal. The BFO switch causes a tone to be produced for tuning purposes. LOOP ANTENNA AS-1863/ARN-83.— This antenna is a flat, one-piece, sealed unit. It consists of four ferrite-cored coils arranged in a rectangle. Two coils line up parallel to the fore-aft axis of the aircraft, and the other two are perpendicular to the axis. Each pair of coils provides a signal that is sent to the receiver for processing. ADF SENSE ANTENNA.— The ADF sense antenna element is basically an aluminum panel connected to the input of the lightning arrester. This panel is encased in fiber glass and mounted flush with the fuselage. The loop antenna is physically mounted on the sense antenna. Functional Description There are three functional modes with the LF/ADF. These modes are (1) ADF mode, (2) loop mode, and (3) antenna mode. The direction finder set provides audio to the intercommunication system in all three modes of operation. ADF MODE.— In the ADF mode, the loop antenna signals are mixed with the nondirectional sense antenna signal in the receiver. This signal is then detected for audio to be sent to the headsets. The bearing coordinate data is produced by the receiver error correction servomotor network. This is then sent to the navigation indicator for display. LOOP MODE.— In the loop mode, the fixed loop antenna RF signal is modulated and detected in the receiver. The resulting audio error signal is used to produce an audio tone signal that is fed to the intercommunication system. The servomotor net work is then manually controlled to null the audio tone. At the null, the output of the receiver will represent relative bearing to the radio station. ANTENNA MODE.— This mode causes the system to act just like a normal radio receiver. It receives a voice or continuous wave (CW) signal at the sense antenna, which is detected and amplified by the receiver. The receiver then sends the audio to the ICS. In this mode of operation, there is no bearing data signal being developed. 2-12



Aviation News
Rolls-Royce to Support V-22 Engines
Rolls-Royce has received $39 million to support AE 1107C engines...
aviationtoday.com
Regional Scan: Latin America
Avianca Upgrades A320s With ROPS Flight display featuring the Airbus...
aviationtoday.com
Rockwell Collins Reports on Project Missouri Radio Test
[Avionics Today April 23, 2014] Rockwell Collins released a statement about...
aviationtoday.com
Regional Scan: Middle East & Africa
Thales, Qatar to Develop OPV-A Thales, Qatar Air Force officials...
aviationtoday.com
Kestrel Makes sUAS Automation Progress
[Avionics Today April 23, 2014] Lockheed Martin's announced progress with its...
aviationtoday.com
Boeing Stands Out Among Lockheed, Northrop 1st Quarter Results
[Avionics Today April 23, 2014] Three of the world's largest aerospace...
aviationtoday.com
QF16: Unmanned Viper Takes Flight
  A pilotless F-16 during flight. Photo: Boeing The U.S....
aviationtoday.com
The Future of Unmanned Flight
Just five years ago, the idea of the futuristic aircraft...
aviationtoday.com
Sikorsky Flies Optionally Piloted Black Hawk
[Avionics Today April 22, 2014] Sikorsky Aircraft Corp. announced a successful...
aviationtoday.com
Time to Rethink UAS in the US
The Federal Aviation Administration’s (FAA) treatment of very small UAS...
aviationtoday.com
FAA Announces First UAS Test Site Operational
The North Dakota Department of Commerce is ready to start...
faa.gov
Mercury Systems to Provide UAS Processing Modules
[Avionics Today April 21, 2014] Mercury Systems announced a new $3.2...
aviationtoday.com
Airbus Corporate Foundation, JetBlue and Luftfahrt ohne Grenzen send humanitarian aid to Haiti
Ten tonnes of medicine, sheets and blankets shipped on JetBlue...
airbus.com
Northrop Grumman Opens Aircraft Integration Center
[Aviation Today April 16, 2014] Northrop Grumman announced its dedication of...
aviationtoday.com
L-3 TCAS System Selected for KC-46A
[Avionics Today April 18, 2014] Boeing has selected the T3CAS Integrated...
aviationtoday.com
F-35 to Make First U.K. Flight in July
[Avionics Today April 18, 2014] This summer's Royal International Air Tattoo show...
aviationtoday.com
FAA Extends Deadline for Final Helicopter Safety Rule
April 17In response to industry feedback and so that the...
faa.gov
The 2014 AMC/AEEC Conference
[Avionics Today April 17, 2014] 2014 marks the 65th year...
aviationtoday.com
Lockheed Martin F-35 Fleet Tops 15,000 Flight Hours
[Aviation Today, April 16] Lockheed Martin’s F-35 Lightning 2 fleet...
aviationtoday.com
AirAsia to implement Airbus Managed Inventory service
• Automatically replenishing inventory levels at AirAsia facilities • Guaranteeing...
airbus.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +