background image

AR2 

 4  

INTRODUCTION TO THE AR2 AVIATION RECEIVER KIT   

 
The Ramsey AR2 Aviation Receiver is a new design of our original Ramsey 
AR1 Aircraft Receiver. The AR1 has been built and loved for years by 
hobbyists with an interest in both aviation and electronics. The AR2 design 
takes the best of the AR1 and adds scanning functions, and a slick metal case 
for superior noise reduction. It is characterized by exceptional sensitivity, 
image rejection, signal-to-noise ratio and stability. It is designed for casual 
"listening in"- on both ground and air communication, for both commercial 
airlines and general aviation. The AR2 has been built by folks of all ages and 
skill levels, and in less time than it takes to fly solo! 
 

118-136 MHz, WHAT YOU CAN EXPECT TO HEAR 

 
A basic fact about the VHF Aviation Band which even licensed pilots can 
overlook or forget is that communications are in the AM mode, not FM, as in 
the case of the FM broadcast band immediately below it, and the VHF public 
service and ham bands immediately above it. 
 
No matter where you live you will be able to receive at least the airborne side 
of many air traffic communications. You'll hear any aircraft you can see, PLUS 
planes up to 100 miles away and more, since VHF signals travel "line of 
sight." An airliner at 35,000 feet altitude is still line of sight to your antenna. 
Similarly, whatever ground stations you may hear are also determined by this 
"line of sight" characteristic of VHF communication. If there are no major 
obstacles between your antenna and an airport (tall buildings, hills, etc.) you'll 
be able to hear both sides of many kinds of aviation communication. Be 
prepared for them to be fast and to the point, and for the same airplane to 
move to several different frequencies in the span of a few minutes! Here's a 
brief listing of the most common types of services in the NAS (National 
Airspace System) with which pilots communicate: 
 
Clearance Delivery 
At most metropolitan airports a pilot communicates with the FAA on a 
frequency called "Clearance Delivery" to obtain approval or clearance of the 
intended flight plan. This communication is done before contacting ground 
control for taxi instructions.  
 
Ground Control 
From the control tower, ground movements on ramps and taxiways are 
handled on the “Ground Control” frequency.  
 
Control Tower 
Runway and in-flight maneuvers near the airport, usually within three miles 
(takeoffs, local traffic patterns, final approaches and landings) are on the 
“Control Tower” frequency.  

Summary of Contents for AR2WT

Page 1: ...control towers centers and planes en route Very sensitive picks up planes 100 miles away Great project for all pilots and flight students Clear concise step by step instructions carefully guide you t...

Page 2: ...Meter LC1 Inductance Capacitance Meter RAMSEY AMATEUR RADIO KITS HR Series HF All Mode Receivers DDF1 Doppler Direction Finder Kit QRP Series HF CW Transmitters CW7 CW Keyer QRP Power Amplifiers RAMS...

Page 3: ...No AR2 Manual Price Only 5 00 TABLE OF CONTENTS Introduction 4 What You Can Expect to Hear 4 Circuit Description 8 Block Diagram 10 AR2 Schematic Centerfold 12 Antenna Considerations 16 Modes of Opera...

Page 4: ...l hear any aircraft you can see PLUS planes up to 100 miles away and more since VHF signals travel line of sight An airliner at 35 000 feet altitude is still line of sight to your antenna Similarly wh...

Page 5: ...pilot on the status of incoming or outgoing aircraft but the pilot remains responsible for landing and takeoff decisions Typical CTAF frequencies are 122 7 122 8 and 123 0 MHz Unicom frequencies are u...

Page 6: ...a cleared to outer marker Contact Tower 118 7 The local Approach Control is saying that the Piper Seneca with the N number tail number ending in 432L is cleared to continue flying an instrument approa...

Page 7: ...AR2 7...

Page 8: ...will have two different frequencies on the inputs which results in four signals on the output The received frequency is connected to one input and the local oscillator or LO is supplied to the other...

Page 9: ...The band pass filter certainly helps and gets rid of all but the strongest image signals outside the band Now that we have our filtered 10 7MHz IF at the output of the IF filter we can do some simple...

Page 10: ...rence 10 25MHz Vtune VCO 118 139MHz 118 139MHz 10 7MHz 450kHz Audio Detector IC Simplified Display Control RSSI IF1 Mixer IF2 Mixer IF AMP RF Amp Detector Antenna Speaker A B C D E F G H Audio Amp I J...

Page 11: ...can be tuned using what is called a varactor diode in the oscillator section A varactor diode is a reverse biased diode that changes capacitance according to the reverse voltage The higher the voltag...

Page 12: ...AR2 12...

Page 13: ...AR2 13...

Page 14: ...a C value of 410 This means the reference clock of 10 25MHz is divided by 410 to give a divider output of 25kHz This value remains constant throughout the AR2 circuit To receive 118 3MHz we have to s...

Page 15: ...is device programs the PLL to get the frequencies desired handles the jog dial by interpreting it s pulses and then writes the data to the displays Quite a bit of coding is required to handle the scan...

Page 16: ...action from the wire but if you re more than a few miles away a decent roof mount job is the way to go A low cost TV antenna works well even better if rotated 90 degrees remember aircraft antennas are...

Page 17: ...eld strength of the signal RSSI 2 Lighting Control Mode This mode allows a user to access an external circuit to remotely control runway lights in small airports by keying the radio at the frequency t...

Page 18: ...te frequency memories from scanner 3 16 Setup Scanner 4 Mode Allows you to save and delete frequency memories from scanner 4 17 Setup skip timer Allows you to select the amount of time to keep a parti...

Page 19: ...uency is already in the list a sign will appear in the lower right to indicate it is already in the list if it is not Press and release the jog dial to add a frequency not in the list Press and releas...

Page 20: ...opinions comments and additions you d like to see in future publications Please submit comments or ideas to Ramsey Electronics Inc or email us at techsupport ramseymail com Attn Hobby Kit Department...

Page 21: ...AR2 21 These pages intentionally left blank...

Page 22: ...AR2 22...

Page 23: ...nd received five extra 1K resistors you can pretty much be assured that the 1K ohm resistors are actually the missing 10 K parts Hum m m I guess the red band really does look orange Ramsey Electronics...

Page 24: ...n Expect to Hear 4 Circuit Description 8 Block Diagram 10 AR2 Schematic Centerfold 12 Antenna Considerations 16 Modes of Operation 17 Warranty 35 Manual Price Only 5 00 Ramsey Publication No AR2 Assem...

Reviews: