Ramsey Electronics Model No. FM-100 Now here’s the ultimate radio transmitter for all of you home brew DJs out there! This all-in-one stereo transmitter has all the features you will ever need for transmitting for a school radio station, around your yard, or even around the block.
PARTIAL LIST OF AVAILABLE KITS RAMSEY TRANSMITTER KITS • FM100 Professional FM Stereo Transmitter • FM25 Synthesized Stereo FM Transmitter • MR6 Model Rocket Tracking Transmitter • TV6 Television Transmitter RAMSEY RECEIVER KITS • FR1 FM Broadcast Receiver • AR1 Aircraft Band Receiver • SR2 Shortwave Receiver • SC1 Shortwave Converter RAMSEY HOBBY KITS • SG7 Personal Speed Radar • SS70A Speech Scrambler • BS1 “Bullshooter” Digital Voice Storage Unit • AVS10 Automatic Sequential Video Switcher • WCT20 Cable
Ramsey Publication No. MFM-100 Price $10.00 KIT ASSEMBLY AND INSTRUCTION MANUAL FOR FM-100 PROFESSIONAL STEREO TRANSMITTER TABLE OF CONTENTS Introduction ......................................4 How does it work ..............................5 Parts List ...........................................13 Assembly Index ................................16 Section Layout ..................................17 Display Layout ..................................18 Main Board Layout............................
INTRODUCTION TO THE FM-100 First we will begin with a little history of stereo transmitters at Ramsey Electronics to give you some idea how we arrived at the FM-100 as our latest stereo transmitter. We have many people call us each day asking questions about our earlier versions of transmitters such as the FM-25 and the FM-10a. Most are questions concerning drifting, sound quality, and transmitting distance.
HOW DOES IT WORK? Here is where we get into a little circuit analysis. If you just want to plug it in and start broadcasting, you can skip this section and read the FCC regulations section. Otherwise there is some insight into why and how this FM-100 works. We will use the schematic located at the center of the manual to analyze the circuit. We will begin with the power supply since it is the most common circuit we will see.
lit. While this may not be the most efficient method of lighting a display, it is the least noisy. U3, the MM5451 is just a large serial shift register made for driving LED segments. Well, the display wouldn’t do much without a smart device to send it some meaningful data. In this case we are using a Motorola microcontroller (U4) to do the job for us.
If you are a close observer, you will notice that U4 derives its clock signal from the PLL. The PLL has a nifty feature of a buffered divided crystal output to drive external devices such as microcontrollers. This is another part of the 32 bits we send to the microcontroller other than the divide by N info. When first powered on, the XCLK line is at the lowest possible divide by C frequency, which is 6MHz / 16 or 375KHz.
The second neat feature is the voice detection capability. Voice detection is used with the auto AGC feature of the FM-100. Essentially pin 8 of U7 goes high when there is a varying signal level seen on the microphone, as compared to the constant level of background noise. When pin 8 goes high, it turns JFETS Q5 and Q6 on which act like voltage controlled pots. The more they are turned on, the less resistance is seen from source to drain.
Part of the output of U11:A is observed for the level indicators. IC U11:B, D4, R54 and C60 comprise a peak hold detector. Part U11:B and D4 make up a real diode, meaning there is no .7 volt drop normally associated with a diode because it is accounted for in the feedback of the opamp. The “real diode” will charge C60 quickly on positive going signals, but it doesn’t discharge it. The discharge cycle is left up to R54. The larger the value, the longer in time the peak hold function is.
MICROCONTOLLER DESCRIPTION The coding of the microcontroller is set up for a simple process of changing frequency. As you will see, there is more than meets the eye, but it’s not so complex when you give it a look. We will start with two given conditions: 1) The unit is powered up, and 2) The unit has been set in setup mode. In this state the tens decimal point is blinking and your frequency may be changed. 1. User presses FREQ UP button. 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.
Since this is a “professional” transmitter, we sincerely hope you put this together in a professional manner. This project will not work as well as you wished if you just slap it together without following good assembly techniques, and follow all instructions. No matter how clear we may think our manual is, if you have any questions give us a call at the factory instead of jumping to conclusions, we will be happy to help you with any problems.
RAMSEY FM-100 PARTS LIST Semiconductors 1 MC145170 Serially programmed PLL (U2) 1 BA1404 Stereo generator IC (U6) 2 LF347 Quad low noise opamps (U11,8) 1 68HC705J2 Custom programmed microcontroller (U4) Marked FM-100 1 X2402 serial EEPROM (U1) 2 LM3915 Log bar-dot bargraph display drivers (U12,U5) 2 MAX291 8th order Butterworth lowpass switched capacitive filters (U9,10) 1 MC2830 Voice activated switch with AGC (U7) 1 MM5451 Serial shift register display driver (U3) 1 79L08 -8 volt voltage regulator (TO92 p
7 4 4 1 1 3 47K ohm resistors (yellow-violet-orange) (R21,28,34,54,67,72,79) 75K ohm resistors (violet-green-orange) (R45,52,77,81) 100K ohm resistor (brown-black-yellow) (R7,51,75,91) 150K ohm resistor (brown-green-yellow) (R46) 220K ohm resistor (red-red-yellow) (R25) 1M ohm resistors (brown-black-green) (R3,38,48) Ceramic capacitors 1 5pF ceramic capacitor (marked 5 or 5K) (C15) 4 10pF ceramic capacitors (marked 10 or 10K) (C18,27,32,82) 2 27pF ceramic capacitors (marked 27 or 27K) (C1,2) 4 47pF cerami
Miscellaneous 1 38KHz crystal (Y2) 1 Mini speaker (SP1) 2 Stereo RCA jacks (J5,6) 1 6 pin Molex connector (J10) 1 4 pin Molex header (J11) 4 5 pin headers (J1,3,7,8) 5 DPDT Push button switches (S1,2,3,4,5) 1 20 pin IC socket 1 3.
PROJECT ASSEMBLY Here we go! To make assembly easier and to stick by the “Learn As You Build” strategy, we will section off the project into different major circuit groups. We will begin with the smaller display board to perfect your assembly skills before we continue with the more crowded sections of the board. Following is a list of all the sections in the manual that we will be going into: [A] Display Board .................................... 18 [B] Part Preparation ................................
SECTION LAYOUT ON MAIN BOARD FM-100 Page 17
DISPLAY BOARD LAYOUT Parts Values Parts Layout Note: Gray components are on the reverse side of the board.
A. DISPLAY BOARD We will begin with the display board oriented in the direction shown. Be sure not to confuse the sides of the board where the parts go. On the board you will see the side marked FRONT, which is where most parts are mounted. We will begin with lower parts and work up to the higher ones. Don’t use sockets for these parts since they need to fit between the front panel and the PC board. 1A. Install R87, a 1K ohm resistor (brown-black-red). 2A.
towards U3 before soldering all 18 pins. 11A. Install D2, one of the small red LEDs. You will notice that if you look A Same height as DS1+DS2 K 1/4" straight at the LED there is a flat side. This indicates the Cathode side of the LED. The Cathode side is also indicated by the shorter of the two leads. Make sure to install the flat side or the shorter lead in the same way as shown in your diagram. They only light up if they are installed correctly.
MAIN BOARD PART VALUES FM-100 Page 21
MAIN BOARD PART LAYOUT FM-100 Page 22
B. PART PREPARATION Well, there isn’t a heck of a lot to do in these next couple of stages, but these steps will help the rest of the kit go smoothly if we get them over with now. 1.) Create L4: Using the small red torroid core and the piece of enameled wire provided with your kit, make a coil consisting of 9 turns. To do this simply thread the wire through the torroid core 9 times as shown here. When done winding, use a hot soldering iron and fresh solder to tin the ends of the wire.
C. MICROPHONE AMPLIFIER 1C. Orient the board in the same direction as shown in the parts layout diagram. 2C. Install R24, a 33K ohm resistor (orangeorange-orange). 3C. Install R70, a 10K ohm resistor (brownblack-orange) 4C. Install R17, a 10K ohm resistor (brownblack-orange) 5C. Install R48, a 1M ohm resistor (brownblack-green). 6C. Install U7, the MC2830 voice detector IC. Make sure the part is oriented correctly before soldering, and that all 8 pins are through the board. 7C.
D. AUDIO MIXER 1D. Install R83, a 10K ohm resistor (brownblack-orange). 2D. Install R88, another 10K ohm resistor (brown-black-orange) 3D. Install R86, a 1K ohm resistor (brown-blackred) 4D. Install R91, a 100K ohm resistor (brownblack-yellow). 5D. Install R65, a 22K ohm resistor (red-redorange). 6D. Install R50, a 1K ohm resistor (brown-blackred). 7D. Install R80, a 10K ohm resistor (brownblack-orange). 8D. Install R85, a 10K ohm resistor (brown-black-orange). 9D.
it. Don’t let this confuse you, so make sure the flat side of the transistor is in the same orientation as shown in the parts layout. 22D. Install C81, a .01uF ceramic capacitor (marked .01, 10n, or 103). This cap is used to filter out noise on the gates of Q5 and Q6. 23D. Install Q5, another BS170 FET. Make sure and mount the flat side in the same orientation as shown in the layout. 24D. Install U8, one of the LF347 quad low noise opamps.
E. SWITCHED CAPACITOR FILTERS 1E. Locate the center of the board where this group of parts is to go. 2E. Install R45, a 75K ohm resistor (violetgreen-orange). 3E. Install R53, a 1K ohm resistor (brownblack-red). 4E. Install R52, a 75K ohm resistor (violetgreen-orange). This part stands upright. 5E. Install R81, a 75K ohm resistor (violetgreen-orange). Another stand-up. 6E. Install R66, a 15K ohm resistor (browngreen-orange).
18E. Install C44, a 10uF electrolytic capacitor, check the polarity before soldering! 19E. Install C67, a 10uF electrolytic capacitor (polarity). 20E. Install C75, a .001uF ceramic capacitor (marked 102 or .001). 21E. Install C74, a .0047uF ceramic capacitor (marked .0047 or 472). 22E. Install C70, a 100pF ceramic capacitor (marked 100 or 101). 23E. Install C66, a .1uF ceramic capacitor (marked .1 or 104). 24E. Install C65, a 10uF electrolytic capacitor.
F. PEAK HOLD AND ACTIVE FILTERS 1F. Install R79, a 47K ohm resistor (yellowviolet-orange). Stands upright. 2F. Install R75, a 100K ohm resistor (brownblack-yellow). Stands upright. 3F. Install R72, a 47K ohm resistor (yellowviolet-orange). Stands upright. 4F. Install R76, a 1K ohm resistor (brownblack-red). Stands upright. 5F. Install R67, a 47K ohm resistor (yellow-violet-orange). Stands upright. 6F. Install R58, a 15K ohm resistor (brown-green-orange). Stands upright. 7F.
16F. Install J8, a 5 pin jumper header. Make sure and leave the longer leads facing up, with the shorter ends soldered to the board. This is where the connection is made to the front panel. 17F. Install C71, a 10uF electrolytic capacitor. Check polarity! 18F. Install C60, another 10uF electrolytic capacitor. 19F. Install C68, a .1uF ceramic capacitor (marked .1 or 104). 20F. Install C64, a 100pF ceramic capacitor (marked 100 or 101). 21F. Install C51, a .1uF ceramic capacitor (marked .1 or 104). 22F.
G. TRANSMITTER This is where we definitely want to have clean soldering skills and proper mechanical mounting of parts. If you need a review, shoot back to the start of the manual in the “STRATEGY” section for tips. Make sure all your parts are flush to the board and not waving in the breeze. You will not only lose performance if parts aren’t installed correctly, but your kit may not work at all. Have patience and follow all directions and you should have no trouble at all! 1G.
9G. Install R16, a 100 ohm resistor (brown-black-brown). 10G. Install R11, a 470 ohm stand up resistor (yellow-violet brown). Be sure to install it exactly as shown in the parts layout. We will be using the exposed end later during testing procedures. 11G. Install R36, a 270 ohm resistor (red-violet-brown). 12G. Install R40, a 10K ohm stand up resistor (brown-black-orange). 13G. Install R32, another 270 ohm resistor (red-violet-brown). 14G. Install R73, a 51 ohm stand up resistor (green-brown-black).
29G. Install C21, a .01uF ceramic capacitor (marked .01, 10n or 103). 30G. Install C20, a .01uF ceramic capacitor (marked .01, 10n or 103). 31G. Install C24, a .001uF ceramic capacitor (marked .001 or 102). 32G. Install C26, a .001uF ceramic capacitor (marked .001 or 102). 33G. Install C85, a 47pF ceramic capacitor (marked 47 or 47K). 34G. Install C82, a 10pF ceramic capacitor (marked 10 or 10K). 35G. Install C84, a 47pF ceramic capacitor (marked 47 or 47K). 36G. Install C28, a .
These capacitors give the crystal the proper loading so that it operates on the correct frequency. In the FM band, our crystal can be off by as much as .01% and most tuners will pick it up just fine. As this crystal is set up, it will be within .001%, which is 10X better, and that’s without tuning! 55G. Install C34, a 220pF ceramic capacitor (marked 220K or 221). 56G. Install C7, a .001uF ceramic capacitor (marked .001 or 102). 57G. Install C11, a 10uF electrolytic capacitor. Check polarity!!! 58G.
H. MICROCONTROLLER This section is a little vague in what’s entailed. The microcontroller really controls the entire circuit, but this section deals with the parts which are fairly exclusive to the controller itself. We’ll wait until later to install the switches because they get in the way while we’re installing the rest of the parts. 1H. Install R21, a 47K ohm resistor (yellow-violet-orange). 2H. Install R20, a 1K ohm resistor (brown-black-red). 3H. Install R18, a 1K ohm resistor (brown-black-red). 4H.
17H. Install D1, a 1N4148 type diode (orange glass body with black stripe on one end). Install it in the same orientation as shown in the parts layout diagram. 18H. Install U4, the IC with the sticker FM-100 into the socket.If your chip has a dot or notch, orient as shown in the parts layout diagram. If your chip has a large “1” on one end, this end is oriented as though it were a notch. It should be placed at the end of the socket closest to R19.
J. JACK AND SWITCHES: Now our project will begin to look complete as we install the jacks and switches. We only have one component section to go after we complete this, so be sure not to lessen the effort you put into making a nice neat project out of this. 1J. Install S4, an unmodified switch that we left alone in section B. Make sure when mounting all of your switches that they are pressed firmly to the board so that they will align properly in the case holes when completed. 2J.
12J. Install J6, the other stereo RCA jack. When installing, make sure it is installed to nicely meet up with J5 and that it is flush with the PC board as well. 13J. Install J11, a four pin Molex header connector. Make sure the short ends are the ones installed in the PC board. That takes care of all of the jacks and switches. Now we want to give the FM100 a thorough check over with the most picky eye that you possess.
K. POWER SUPPLY Oh yes! the final section of our project and then on to testing and playing! Don’t rush now, this section has many parts that are very critical in orientation, especially the large electrolytic capacitors. If they are installed in reverse, the electrolyte in the capacitor begins to boil creating a grand amount of pressure inside a metal can part. Even though they have stress relief on the tops, they still tend to explode like a firecracker.
9K. Install D6, a 1N4002 type diode. Make sure the striped end is installed correctly! 10K. Install D7, the last 1N4002 type rectifier diode. Again check the striped end for correct installation. 11K. Install VR4, the 79L08 -8 volt regulator. Make sure the flat side of the part is oriented as shown. This part “smoothes” out the raw DC from C55. 12K. Install C56, a 10uF electrolytic capacitor.
19K. Install C86, a 3300uF electrolytic capacitor. Notice how there are three holes available for the negative side of the capacitor. Only one of these needs to be used by the capacitor. These holes just make allowances for various lead spacings, just use the best fit. Make sure and check polarity! 20K. Install C52, the other 3300uF electrolytic capacitor. Again make sure the part is installed in the correct orientation. 21K. Install VR2, the 7808 +8 volt power regulator.
L. 1 WATT MODULE 1L. Note the position of C92 on the PC board. Do not install any part in this position. 2L. Install R33, a 1K ohm stand up resistor (brown-black-red). 3L. install D5, a 1N4148 type diode (small glass orange body with black stripe on one end). Make sure and mount the stripe in the same direction as shown in the parts layout. 4L. Install R39, a 1K ohm resistor (brownblack-red). 5L. Install C91, a 100pF ceramic capacitor (marked 100 or 101). 6L. Install C79, a .
4M. Your 110VAC line cord has three wires; black, white, and green. The black wire does not have a factory installed Molex pin on it; this is the HOT side of the power connection. Strip and tin the end of the black wire. 5M. Locate the female Molex connector and insert the white linecord wire, as shown, into the jack. You will notice there is a small catch tab on one side of the pin. Insert the pin into the Molex jack so the tab faces the side with the slotted holes.
silkscreened side of the panel. Mount the plastic nut between the silk screened side of the case and the cap. Make sure the plastic nut is tightened well on the inside so it doesn’t become loose later. 9M. Bend the pre-tinned end of the 3” piece into a quarter loop so that it holds onto the solder tab of the fuse holder for soldering. Solder the wire to the end tab of the fuse holder. 10M.
N. FRONT PANEL ASSEMBLY 1N. Align the front panel PC board with the holes in the front panel assembly. 2N. Check the LEDs for proper installation height and positioning. If they are misaligned, now is a good time to correct that. 3N. Using 3 of the the 4-40x1/4 screws, mount the board securely to the front panel. 4N. Admire your work up to this point. (WOW!) O. PC BOARD MOUNTING AND CASING To make testing of the PC board easier, it is convenient to have the PC board mounted to the bottom of the case.
P. FINAL TESTING AND CALIBRATION We’re almost ready to plug it in. We will need the following equipment to give it a true test. A DMM or voltmeter. A sound source such as a CD player or tape deck. A microphone with the appropriate jack. A receiver (preferably digital tuner). The tuning tool sent with your kit. 1P. Adjust R15, R23 and R35 to their center positions. 2P. Make sure the power switch is off. Plug in your FM-100 to 110 volts. 3P. Turn on the FM-100.
14P. Plug your microphone into the microphone jack, and crank up the microphone gain. 15P. Press the MIC button, verify the MIC LED turns on. 16P. Talk into the microphone; you should hear sound from the receiver and the LED meters should indicate sound. 17P. Connect your sound source to either J5 or J6, the stereo RCA jacks. 18P. Play some tunes through the unit and make sure the controls on the front are working. 19P. Press the AUTO AGC button once, the MIC ON LED should blink rapidly.
Q. FINAL CASE UP 1Q. Install the antenna grommet so the antenna does not short to the case. 2Q. Install the top case half using the self tapping case screws. 3Q. Install one small sheet metal screw into each of the holes for the RCA jacks on the back panel. This prevents physical damage to the RCA jacks. 4Q. Use the four sticky pad feet on the bottom of the case in each corner. 5Q. Install all five switch buttons on the end of each switch. 6Q.
TROUBLESHOOTING PROBLEM: Nothing happens at all when I turn it on. SOLUTION: Check your fuse. If it is blown you will want to check section L for rear panel wiring or section K for the power supply. Use a volt meter to check your power supply voltages. Verify that there is +8, +5, and -8 volts on the outputs of the regulators. Also check U2 pin 3 for a 1.5MHz clock signal. PROBLEM: Everything works, but only some or no lights light up on the front.
SOLUTION: Make sure it’s not coming from your other components in combination with this unit. Some components don’t deal with RF very well. We once had a CD player that wouldn’t even play with low power RF nearby. Try using ferrite beads around the audio connectors. You can find the beads in computer accessory magazines and electronic magazines. PROBLEM: Unit doesn’t store last frequency. SOLUTION: Don’t forget to get out of setup mode to set the frequency before shutting off the power.
ADJUSTING YOUR FM-100 TRANSMITTER: Keep all tests very brief until you have carefully chosen an open operating frequency in the FM broadcast band. 1. Transmitting Frequency: After finding a suitable "open" frequency in the 88-108 MHz FM band, adjust the frequency by first getting the FM-100 into setup mode by pressing both FREQ keys at the same time. Then use FREQ UP and FREQ DOWN keys until you hear the carrier frequency on a nearby FM radio.
USING THE FM-100 WITHIN THE HOME: A most practical use for the FM-100 would be to connect it to the main stereo system within a large home so that whatever is playing on the main system can also be tuned-in on portable FM radios in other rooms, the garage or in the yard. This connection consists of using shielded audio cables to connect the auxiliary "line audio" output of your cassette deck, CD player or other stereo device to the audio inputs of the FM-100.
ANTENNA IDEAS: Although use of the included whip antenna is recommended, you may want to use an external antenna to get a more uniform coverage. Use an external antenna mounted on the rear F connector to expand your coverage. Ramsey Electronics now offers an antenna called the “Tru-Match FM Broadcast Antenna”. This antenna has been specifically tested and designed for the FMseries of micropower transmitters, and will help you get the most out of these products.
ANTENNA ALTERNATIVES: If your situation involves a single large building or multi-level home where reception from the FM-100 antenna may tend to be uneven because of walls and other VHF path obstacles, you might set up the FM-100's output in a "carrier-current" configuration. If you know how, then do so - safely.
USING YOUR FM-100 • Setting the frequency: [1] Press both FREQ UP and FREQ DOWN at the same time. You should hear a confirming low then high tone. The 10’s digit decimal point should blink. [2] Press and hold a FREQ button; the frequency should scroll through the values. [3] When frequency is acceptable, press both FREQ UP and FREQ DOWN. You will hear three short quick beeps to let you know the data is written to non-volatile memory.
APPENDIX A: FCC RULES AND INFORMATION The Rules of the FCC (Federal Communications Commission) and your kit built FM Stereo Transmitter. An basic introduction of applicable FCC regulations. This basic introduction is just that: basic and introductory. A complete and thorough explanation of the FCC rules requires a reading of the regulations contained in the “Code of Federal Regulations, Part 15.
Here are the primary "dos and don'ts" picked from the current FCC Rules, as of May, 1990. This is only a brief look at the rules and should not be construed to be the absolute complete legal interpretation! It is up to you to operate within the proper FCC rules and Ramsey Electronics, Inc. cannot be held responsible for any violation thereof. 1. In the past, no "two-way communications" use of the 88-108 MHz FM broadcast band was permitted. This prohibition does not appear in the current edition of Part 15.
a. The transmitter must NEVER be tuned to a frequency above 108 MHz, specifically the band 108-121.94 MHz, FCC Rule 15.205 lists this band as restricted, due to potential interference with aircraft navigation equipment. b. The "bandwidth" of your transmission is limited to 200 KHz, centered on the actual operating frequency. Since 200 KHz is enough spectrum space for several different FM stations, this is a "generous" limitation designed to accommodate cruder FM devices.
DISTANCE FROM TRANSMITTER ANTENNA METERS FEET FIELD STRENGTH (µV) TOTAL RECEPTION AREA 3 10 250 314 FT 6 20 125 1256 FT 12 39 63 4800 FT 24 78 31 19113 FT 48 157 15 1.8 ACRES 96 315 7.5 7.2 ACRES 192 630 3.8 28.6 ACRES 384 1260 1.9 11.4 ACRES 768 2520 .95 458 ACRES 1536 5036 .5 1830 ACRES APPENDIX B: UNDERSTANDING LEGAL "FIELD STRENGTH" A "microvolt" is one-millionth of one volt and designated "µV" in the following explanations.
In all cases, the field strength of a signal decreases in direct proportion to the distance away from the antenna. Power decreases by the square of distance: for every doubling in distance, the signal power is quartered, but the field strength voltage is only halved. Using this theory, we can construct a simple chart to show the maximum permitted performance of a non-licensed FM band transmitter.
about 114 acres. A quick glance at stereo FM receiver specifications shows typical sensitivity of 1.7 µV before considering high-gain antennas or preamplifiers. Your non-licensed signal can provide serious competition to a public broadcast station fifty miles away, a station which someone in your neighborhood may have set up a special antenna to enjoy. Calibrated "field strength meters" such as described in the ARRL Radio Amateur's Handbook can detect signals down to about 100 microvolts.
SUMMARY The present edition of Part 15 of the FCC rules does not provide detailed guidance on ALL aspects of using a low-power transmitter such as the FM100. The main point is that you may not cause any interference whatsoever to licensed broadcast services and that you must be willing to put up with any interference that you may experience. Lawful use suggestions for the FM-100 1. Build and adjust this kit strictly according to the published instructions. 2. Use the whip antenna supplied. 3.
intended for non-licensed operation under Part 15 Rules. You will find such notices written up for the front or back of the instruction manual for nearly any computer or video accessory that you have seen in recent months. Consult the Part 15 Rules for the exact wording of such notices.
Final comment A well-informed person will see today's FCC Rules to be evolving and progressively less-restrictive. Even though today's technology is far more complex than what was possible at the time of the Communications Act of 1934, the FCC rules are becoming more relaxed, giving radio experimenters more and more opportunities to explore many frequency bands, using many communications modes, with no need for a formal license of any kind.
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.
PROFESSIONAL FM STEREO TRANSMITTER KIT Quick Reference Page Guide Introduction ..................................... 4 How does it work ............................. 5 Parts List .......................................... 13 Assembly Index ............................... 16 Section Layout ................................ 17 Display Layout ................................ 18 Main Board Layout .......................... 21,22 Schematic Centerfold ..................... 34,35 Troubleshooting ...................
