WSR-1A WEATHER SATELLITE RECEIVER Ramsey Electronics Model No.
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Ramsey Publication No. WSR-1A Price $5.00 KIT ASSEMBLY AND INSTRUCTION MANUAL FOR WSR-1A WEATHER SATELLITE RECEIVER KIT TABLE OF CONTENTS Introduction to the WSR-1A ............. Parts list ........................................... Strategy and Tips ............................. Circuit Description ............................ Construction ..................................... Schematic ........................................ Casing it up ...................................... Initial Testing .........
INTRODUCTION TO THE WEATHER SATELLITE RECEIVER The days of guessing the weather by looking at the clouds overhead have just ended. Now you can look at the clouds from above! This project will allow you to receive pictures from satellites 600 km overhead.
sensors are facing away from the earth, it sends the infrared data. The user then sees the data as two images side by side, on the left the visible light data is seen, and on the right, infrared data is seen. In between the images are synchronization pulses that help computers to align the individual lines precisely. These particular satellites continuously transmit an FM signal modulated with a 2400Hz tone. This tone is very precise in frequency so the image seen is aligned properly.
RAMSEY WSR PARTS LIST Semiconductors 1 LM386 Audio Power Amplifier (U1) 1 MC13135 FM Demodulator (U2) 1 MC145170 Digitally controlled Phase Locked Loop (U3) 1 MC68HC705K1 Microcontroller (U4) 1 74HC138 3 to 8 Line Decoder (U5) 1 LM358 Operational amplifier (U6) 1 BB505 Varactor Diode (D1) 5 2N3904 NPN transistors (Q3,Q4,Q5,Q6,Q7) 3 2SC2498 or 2570 NPN transistors (Q1,Q2,Q8) 8 Red mini LEDs (D2,D3,D4,D5,D6,D7,D8,D9) 1 7805 5 Volt regulator (VR1) Resistors 1 4.
RAMSEY WSR PARTS LIST Capacitors cont... 4 22pF ceramic capacitors (marked 22) (C29,C44,C45,C53) 1 15pF ceramic capacitor (marked 15) (C30) 2 10pF ceramic capacitors (marked 10) (C31,C32) 1 220pF ceramic capacitor (marked 220, or 221) (C52) 1 2 or 2.2pF ceramic capacitor (marked 2 or 2.
RAMSEY “LEARN-AS-YOU-BUILD” ASSEMBLY STRATEGY Be sure to read through all of the steps, and check the boxes as you go to be sure you didn't miss any important steps. Although you may be in a hurry to see results, before you switch on the power check all wiring and capacitors for proper orientation. Also check the board for any possible solder shorts, and/or cold solder joints.
WSR-1A CIRCUIT DESCRIPTION The Weather Satellite Receiver is a fairly complex receiver as compared to most of the other receiver kits that are sold. This receiver contains circuitry found in very high end receivers and transceivers. This is due to the high accuracy of reception required to be able to continuously monitor various satellite transmissions, and be right on frequency every time.
allows only frequencies in the needed range to come through. By doing this, it reduces the noise produced by a weak reception, since noise covers the entire audio spectrum, but we are only interested in the spectrum around 2400Hz. After the audio filtering, the audio is first tapped to go to a decoder card on a PC. This way the adjustment of the volume will not alter the level of the voltage going to the PC.
CONSTRUCTION OF THE WEATHER SATELLITE RECEIVER Sort out all of your parts to begin with, making sure you have all of the parts required. You can use old egg cartons to hold various parts to make them easier to find. We will begin building the kit from the back side of the board where all the jacks will eventually be placed. Make sure to mount parts on the correct side! You will want to use the parts layout diagram to assist you in finding where the parts go. 1. Install J4, the power jack.
15. Install C26, a .001uF ceramic capacitor (marked .001, 1n, or 102). 16. Install R15, a 1K ohm resistor (brown-black-red). 17. Install R13, a 100K ohm resistor (brown-black-yellow). 18. Install D1, a BB505 varactor diode (orange glass body with printed characters marking the part number). This varactor diode allows the phase locked loop to operate by adjusting the reverse bias voltage on this diode. This diode is the capacitive part of the local oscillator, and L8 is the inductive part.
29. Install C32, a 10pF ceramic capacitor (marked 10). 30. Install R38, a 270 ohm resistor (red-violet-brown). 31. Install C31, another 10pF ceramic capacitor (marked 10). 32. Install C29, a 22pF ceramic capacitor (marked 22). 33. Install L8, a 84885-5 variable inductor (smaller metal case with green plastic.) This coil is the inductive part of the voltage controlled oscillator of the PLL. 34. Install C54, a .01uF ceramic capacitor (marked .01, 103, or 10n), located near J5. 35.
49. Install C18, a 100pF ceramic capacitor (marked 100 or 101). 50. Install C11, another 39pF ceramic capacitor (marked 39). 51. Install C17, another 100pF ceramic capacitor (marked 100 or 101). 52. Install C8, a 2pF or 2.2pF ceramic capacitor (marked 2, or 2.2). 53. Install L4, a four turn wire wound inductor (can’t miss em, they look like tight springs!) 54. Install L5, another four turn inductor.
64. Install R7, a 1K ohm resistor (brown-black-red). 65. Install R8, a 68K ohm resistor (blue-gray-orange). 66. Install R16, a 22K ohm resistor (red-red-orange). 67. Install C28, a .1uF ceramic capacitor (marked .1, 104, or 100n). 68. Install C33, a .1uF ceramic capacitor (marked .1, 104, or 100n) 69. Install R24, a 1K ohm resistor (brown-black-red). 70. Install TP4 with a 1/2” piece of scrap component lead. Small loop fo 1/2" test probes. 71. Install C34, another .
80. Install C15, a 100uF Electrolytic capacitor. Pay close attention to the polarity markings! 81. Install L7, the LB53303HK variable shielded coil. (silver metal case with orange plastic). Solder all of the leads including the metal case pins securely to the board. 82. Install R37, a 10K ohm trimmer pot (yellow adjustment marked 103). 83. Install R17, a 470 ohm resistor (yellow-violet-brown). 84. Install R6, a 10K ohm resistor (brown-black-orange). Now we begin assembly of the audio stages.
101. Install C16, another 10uF electrolytic capacitor. Check polarity! 102. Install R14, a 3.3K ohm resistor (orange-orange-red). Now it is time to begin installing the microcontroller and associated circuitry. If you haven't already, take a break and grab a Coke, relax, and get ready to finish up the rest of your weather satellite receiver. Also check your previous work for solder bridges and cold solder joints. 103. Install C52, a 220 pF ceramic capacitor (marked 220, or 221) 104.
7805 Topside PCBoard 117. Install VR1, the 5 volt regulator. Make sure the tab is facing the PC board when it is bent over as shown in the diagram. If you wish you can lightly solder the tab to the topside of the circuit board for mechanical stability. Don’t worry about overheating the part, regulators and almost all parts nowadays are very tolerant to soldering temperatures. 118. Install R19, a 10K ohm resistor (brown-black-orange). 119. Install C51, a 10uF electrolytic capacitor.
you will see some polarity markings. The pin marked with the positive symbol (+) is inserted in the hole that is not touching the ground plain on the top side of the board. 131. Install J3, the RCA type jack. This is where you will get the 2400Hz audio without going through the volume control. 132. Install J1, the 3.5mm stereo jack. This jack is originally for stereo hookup, but only one channel is being used, so a mono male jack will work fine for connection.
138. Now it is time to install the LED indicators, D2 - D9. These are a little tricky since they will have to have long enough leads to reach the holes in the display panel of the case and knob set. Look at the diagram to assist you in placing these parts. If diodes are installed backwards they do not light. Identify which lead is which in the following diagram, and make sure and mark the cathode (k) lead of your LEDs with a marker if you are in question.
Align the main board with the display board and notice how the pads on each board line up with each other. To assist with assembly, as well as provide mechanical stiffness, solder a piece of scrap wire supplied with the kit between the jumper point on the main board and the display board. Be sure that the PC boards are seated at right angles. Daughter PC board Magnif ied v iew Solder f illet betw een PC boards Main PC board Solder f illet betw een PC boards 143.
CASING IT UP 1. Locate the case and knob parts. The following is what you should have: 1 Rear panel with square hole 1 Front panel with the volume hole 4 Machine screws 2 Plastic panel holders 1 Top section of case 1 Bottom section of case 3 Decorative push button caps 2 Knobs 2. Slide the PC board into the slots on the aluminum bottom piece of the case, parts side up. 3. Using the front panel, line up the LEDs to their respective holes. 4.
INITIAL TESTING To begin initial testing we will need a few items to make the job a little easier on ourselves. Gather these things together and we will begin. “Diddle Stick” plastic alignment tool (for coils) 12VDC Power supply or battery Appropriate jacks and connections for hookup A signal generator (not required) Frequency counter Voltmeter 1. Connect 12VDC power to your WSR-1 through J4 making sure that the center lug is positive.
9. Turn the volume up 1/4 clockwise. You should be hearing some noise from the speaker buzzer. If not, check to make sure that lead TP1 is connected to lead TP2 on the circuit board. 10. Adjust the slug in L7 first for greatest noise, then adjust L4 and L5 for even more noise. Adjust volume if necessary. Repeat these steps until optimized. To adjust L4 and L5, stretch and contract the coils with your nonmetallic tuning tool until noise is stronger.
TROUBLESHOOTING TIPS PROBLEM: Very little noise from the speaker when adjusting the coils. Adjusting has little effect. SOLUTION: Check Y2 for proper frequency, and then check TP4 for about 0.4 volts then channel 1 is selected (see step 6 of initial testing). If you don't have either of these, your problem lies in the PLL not operating as it should. Check around the local area using your parts list and schematic as a guide. We bet you will find a cold solder joint or a solder bridge somewhere.
ANTENNAS There are several considerations when deciding what antenna to use with your WSR-1. As with almost everything there are some sacrifices to be made with each gain. Here are a few ideas, pros and cons that you can go by when choosing a suitable antenna. The crossed Yagi antenna is a popular form of antenna for polar orbiting satellite reception. This antenna is about the size of a TV antenna, has greater gain, yields stronger signals, and must be aimed towards the satellite as it passes.
The last practical usable type is the volute VHF antenna. It looks like a twisted set of wire, but it is quite effective for receiving satellites, since it doesn’t have as many nulls and peaks due to polarization of RF signals. These are a little tough to assemble out of household equipment, but are widely available through weather satellite antenna companies. Notice that a dish is not required for these frequencies.
BUILDING AN ANTENNA (for your WSR-1 weather satellite receiver) We will show you the dimensions and the connections required as well as the materials we used to make a turnstile antenna, but if more information is needed, we advise you to look into an ARRL handbook, or one of the many antenna books out on the market. Look at Fig A, the antenna wiring diagram. You'll notice that there are two different types of coaxial cable involved.
13.13 in TURNSTILE WIRING DIAGRAM 13.13 in 13.13 in 13.
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PREAMP INSTALLATION This part assumes that you have completely assembled your preamp that came with this kit. This preamp operates off of the power from your weather satellite receiver through the antenna cable of your radio, so care has to be taken so that you don’t short out any connections. Installation of the preamp is fairly simple, yet there are a few considerations you will wish to look into before you continue.
HOW TO RECEIVE A TRANSMISSION The easiest way to receive a transmission is to know when one is coming, and what format it will be in. There are several different satellite formats out there, but the most common and useful is NOAA. For now we will describe how to get NOAA transmissions and display them on a PC. Other satellites will follow as you gain more insight into what is going on.
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SPECIFICATIONS Sensitivity ...................................................... 1uV or -107dBm without preamp -122dBm with preamp (15 dB gain) Outputs ......................................................... 1 adjusted speaker output 1 set line level output 1 tape recorder control output Power ............................................................ 12VDC @ .20A Filtering, input ............................................... Two section helical filter Filtering, first IF ............................
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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.
WSR-1A Weather Satellite Receiver Quick Reference Page Guide Introduction to the WSR-1A ................... Parts list ................................................. Circuit Description .................................. Construction .......................................... Schematic .............................................. Initial Testing ......................................... Trouble Shooting ................................... Antennas ...............................................
