AIRCRAFT RECEIVER KIT Ramsey Electronics Model No. AR2 A new and improved version of our popular Aircraft Receiver kit, this new model features an LCD display, scan function, and increased sensitivity, all in a rugged metal enclosure.
PARTIAL LIST OF AVAILABLE KITS: RAMSEY TRANSMITTER KITS • FM10A, FM25B, FM30, FM Stereo Transmitters • FM100B, FM35 Professional FM Stereo Transmitters • AM1, AM25 AM Broadcast Band Transmitters RAMSEY RECEIVER KITS • FR1 FM Broadcast Receiver • AR1 Aircraft Band Receiver • SR2 Shortwave Receiver • AA7 Active Antenna • SC1 Shortwave Converter RAMSEY HOBBY KITS • SG7 Personal Speed Radar • SS70C Speech Scrambler/Descrambler • TT1 Telephone Recorder • SP1 Speakerphone • MD3 Microwave Motion Detector • PH14 Pe
Ramsey Publication No. AR2 Manual Price Only $5.00 INSTRUCTION MANUAL FOR AIRCRAFT RECEIVER TABLE OF CONTENTS Introduction .......................................... 4 What You Can Expect to Hear ............ 4 Circuit Description................................ 8 Block Diagram ................................... 11 AR2 Parts List.................................... 14 Assembly Instructions........................ 16 AR2 Schematic Centerfold ................ 18 Antenna Considerations ....................
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.
ATIS – Automated Terminal Information System ATIS, is a repeated broadcast about basic weather information, runways in use, and any special information such as closed taxiways or runways. ASOS/AWOS – Automated Surface Observing System/Automated Weather Observing System This system is similar to ATIS but usually located at un-towered airports. Approach Control & Departure Control These air traffic radar controllers coordinate all flight operations in the vicinity of busy metropolitan airport areas.
routed via computers to the proper company, relieving some of the necessity for routine voice communication. With ACARS, routine items such as departure reports, arrival reports, passenger loads, fuel data, engine performance data, and more can be retrieved from the aircraft at automatic intervals. The transmission will sound like a short data burst to the ABM1 user. THOSE FAST-TALKING PILOTS AND CONTROLLERS! Aviation communication is brief but it is clear and full of meaning.
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CIRCUIT DESCRIPTION Radio Basics: We’ll take the circuit section by section; the letters show which part of the block diagram we’re explaining in each section. The AR2 is a simple super-heterodyne receiver. A heterodyne receiver is a receiver that first converts the desired received frequency into an IF frequency, or Intermediate Frequency.
have to be set at 118.300 MHz + 10.700 MHz or 129.000MHz. It would then be sent to the mixer and on the output there would be 129.000MHz (LO), 118.3MHz(Fr), 247.3MHz(Sum) and 10.700MHz (IF). (See Figure 1) After the mixer we use a narrow-band filter (E) to reject everything but the 10.7MHz IF signal output from the mixer. This works well because 10.7MHz is far from the next highest frequency, 118.3MHz, so it’s easy to reject everything but the signal of interest.
AM + 450kHz Detector + Audio Out Since the AR2 is a relatively complex (and educational!) product, it’s easiest to show you how things work by using a block diagram and explaining the different sections. This is a simplified block diagram, but is suitable for our needs. Block A. RF band pass pre-filter. This is one of the two filters that helps reject image frequencies.
Display /Control Microcontroller K A 118-139MHz Antenna AR2 • 11 L J PLL B RF Amp C RSSI 10.25MHz Vtune 118-139MHz VCO IF1 Mixer D 12V F IF AMP 10.25MHz Reference 12V Regulator M E 10.
Block G. This is the main detector, AGC, 2nd LO, reference oscillator, and filtering all wrapped into one part. Block H. 2nd IF filtering. This section is for further attenuating adjacent signals. The goal is to reduce signals 25kHz away more than 90dB, or the range of the AGC of the detector component. Two cascaded 450kHz filters are used here on top of the 10.7MHz ceramic filter. Block I.
being “imposed” on the VCO. It also provides some amplification to give the VCO 0-12V of tuning from a 5V PLL part. Block K. The microcontroller is the “brains” of the entire project. This 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 scanning functions and the user interface, so don’t underestimate what goes on inside this little device! Block L.
AR2 PARTS LIST: CAPACITORS 2 3.3 pF ceramic capacitors [marked 3.3] (C25,28) 1 5 pF ceramic capacitor [marked 5] (C23) 1 10 pF ceramic capacitor (C32) 2 22 pF ceramic capacitors(C24,38) 1 56 pF ceramic capacitor (C63) 1 62 pF ceramic capacitor (C54) 4 82 pF ceramic capacitors (C30,31,33,34) 4 100 pF ceramic capacitors (C1,2,3,6) 15 1nF disc capacitors (marked .001 or 102) (C10,12,15,22,26,27,29,35,37,39,42,53,55,56,65) 7 0.01 µF disc capacitors [marked .
SEMICONDUCTORS 1 1N4000 series diode [any value from 1N4000 to 1N4007] (D1) 1 2SC2570A NPN UHF transistor (Q1) 2 2N3904 NPN transistors (Q2,3) 1 LM7812 12 volt regulator (VR1) 1 78L05 5 volt regulator [looks like a transistor, marked 78L05] (VR2) 1 BB505 varactor diode [marked BB505.
ASSEMBLY INSTRUCTIONS In ALL PC board assembly steps, our word "INSTALL" means to do this: • Insert the part, oriented or "pointed" correctly, into its holes in the PC board. • If helpful, gently BEND the part's wire leads or tabs to hold it into place, with the body of the part snugly against the top side ("component side") of the circuit board. • Solder ALL wires or pins of the part.
8. Install C12, another 1nF disc capacitor (marked .001 or 102). This part also needs to be mounted on the opposite side of the PC board. 9. Install J6, one of the 8 pin dual row connectors. This part is placed from the back of the board, the side you’ve been soldering so far. The Here at the shop we typically insert a number of parts through the board, bend the leads out so that they stay put, and solder a group of parts all at one time.
SCHEMATIC CENTERFOLD AR2 • 18
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progress is not a bad thing and when you come back you'll have fresh eyes and renewed vigor to finish. Hey, we all like to take frequent breaks here at the factory . . . but management isn’t as kind to us as you can be to yourself! 14. Install U6, one of the LMC6482AIN ICs. It’s located near the center of the PC board. You’ll see the PC board silkscreen shows a notch on one end of the part; this corresponds to the notch on the IC and shows you which way to place the part.
Now we’ll start installing the other components, starting at the front of the PC board and working our way around. This will make it easier to find the parts you’re placing. There’s no polarity on the disc capacitors or resistors. You can make the board look more professional by having all the writing on the caps and all the tolerance bands on the resistors point in the same direction. But the kit will work just as well no matter which way these parts face. 21. Install C18, 0.01 µF disc capacitor (marked .
with the number on it and you’ll see the outline showing where to place this flat side on the PC board silkscreen. Bend the center lead out to fit in the holes and push the part down close the circuit board without forcing. Solder the transistor. 34. Install R12, 47K standup ohm resistor (yellow-violet-orange). 35. Install C23, 5 pF ceramic capacitor (marked 5). 36. Install C43, 0.1 µF disc capacitor (marked .1 or 104). 37. Install C40, 20 nF ceramic capacitor (marked 20M). 38.
three leads. 56. Install C48, 35 pF trimmer capacitor (round red part with adjustment). This part can be installed either way. 57. Install C54, 62 pF ceramic capacitor (marked 62). 58. Install R18, 22K ohm standup resistor (red-red-orange). The silkscreen for this part is hard to see but you know it’s in the area; use the Layout Diagram to locate it if you need to. Be very careful with the red and orange color bands on resistors, and also the violet/brown bands.
76. Install C28, 3.3 pF ceramic capacitor (marked 3.3). 77. Install L2, an 11 turn air coil. 78. Install C33, 82 pF ceramic capacitor (marked 82). 79. Install C27, 1nF disc capacitor (marked .001 or 102). 80. Install C55, 1nF disc capacitor (marked .001 or 102). 81. Install C50, 10 µF electrolytic capacitor. Remember to place the longer positive lead in the hole marked with a ‘+’ sign. 82. Install C49, 0.1 µF disc capacitor (marked .1 or 104). 83. Install C57, another 0.1 µF disc capacitor (marked .
97. Install VR1, the LM7812 12 volt regulator. The hole in the large metal part of the regulator is there so that you can attach the part to the board with a screw and nut. This provides a better heatsink for the regulator. Bend the leads down so that the part can lay flat on the circuit board, then solder the part in. 98. Install D1, the 1N4000 series diode (any value from 1N4000 to 1N4007). The white or gray band on the part should be lined up with the white band on the circuit board. 99.
116. Install R36, 2.7k ohm resistor (red-violet-red). 117. Install C65, 1nF disc capacitor (marked .001 or 102). 118. Install R37, 10K ohm resistor (brown-black-orange). 119. Install C58, 2.2 µF electrolytic capacitor. Remember polarity! 120. Install C59, the other 2.2 µF electrolytic capacitor. Again, place it correctly or it won’t work when you fire up the kit. 121. Install C64, 0.01 µF disc capacitor (marked .01 or 103 or 10nf).
Now we’ll install some of the larger connectors and parts, then we’ll be ready for a final checkout of our assembly. And then . . . the moment of truth, applying power to your kit. 137. Install J7, BNC PC mount jack. Be sure the part is flat on the PC board before soldering. That will ensure a good fit when you assemble the case. Also, the ground leads on this part will require a bit more time so be patient when soldering them. 138. Install J9, 3.5mm stereo headphone jack.
and matching 1-64 hex nuts. Place the speaker into its position on the backside of the front panel between the power and squelch knobs with the speaker wires going up toward the top of the case. They’re going to loop over the front panel when we connect it later. Attach the speaker to the front panel using the screws and nuts, screws coming in from the front panel and nuts on the backside to look nice and neat. 148.
sure they’re oriented correctly using the dot or notch on the part and the notch marked on the PC board. Then take a look at all of the electrolytics to be sure they’re installed in the right way. Better to take a few minutes now than to have a part damaged or destroyed because you’re in a rush to apply power. ANTENNA CONSIDERATIONS An antenna for your AR1C can be as simple as a 21" piece of wire or a fancy roof-mounted aviation antenna.
Here’s where we separate the folks with test equipment from the folks who don’t have any. Either way your AR2 will receive the entire aircraft band quite nicely but if you’ve spent money on a signal generator we’re pretty sure you want to get some use out of it. Regular Tuning Mode: Without a signal source to work with you’ll have to tune in a frequency and adjust C48 as best you can. It’s not critical; you’ll still receive signals quite nicely if you don't adjust it but it may make them clearer if you do.
The AR2 uses an advanced way to access the many useful features built in to the unit. What looks like a volume control at first glance is actually a jog dial. No, it doesn’t go for a jog at the end of a long work day, instead it allows you to enter values digitally in a convenient way. There are a few modes of entry of using the jog dial: a. Turn clockwise and counter clockwise b. Press the knob and turn c. Press the knob briefly d. Press and hold.
10. Skip Scanner 2 Mode. This mode allows you to scan up to 20 frequencies saved in the Scanner 2 Setup mode, only this will automatically skip to the next frequency after a specified time. 11. Skip Scanner 3 Mode. This mode allows you to scan up to 20 frequencies saved in the Scanner 3 Setup mode, only this will automatically skip to the next frequency after a specified time. 12. Skip Scanner 4 Mode.
Standard Scanner Modes 1-4 and skip modes: Use the jog dial to select a frequency other than what is currently running. Press and release the jog dial to skip to the next active memory Press and hold the jog dial to prevent stopping at this frequency for the duration of the selection of this mode. Skipping to next channel will occur after timeout in skip mode only.
TROUBLESHOOTING Hopefully you’ll never need this section! If you have a problem with your kit, don’t panic. A sensible, logical approach and a clear head will usually point you to your trouble spot. The first thing to do is to look over the board again and check to be sure that: • • All parts have been installed unless you were instructed otherwise. All parts that have a polarity such as ICs, diodes, voltage regulators, and electrolytic capacitors are placed correctly.
The Ramsey Kit Warranty Please read carefully BEFORE calling or writing in about your kit. Most problems can be solved without contacting the factory. Notice that this is not a "fine print" warranty. We want you to understand your rights and ours too! All Ramsey kits will work if assembled properly. The very fact that your kit includes this new manual is your assurance that a team of knowledgeable people have field-tested several "copies" of this kit straight from the Ramsey Inventory.
TABLE OF CONTENTS Introduction ..........................................4 What You Can Expect to Hear.............4 Circuit Description ................................8 Block Diagram................................... 11 AR2 Parts List ................................... 14 Assembly Instructions ....................... 16 AR2 Schematic Centerfold................ 18 Antenna Considerations.................... 29 Setup and Testing ............................. 29 Troubleshooting .............................
