Instruction/ maintenance manual of the product FM10A Ramsey Electronics
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FM STEREO TRANSMITTER Ramsey Electronics Model No. FM10A • Great for transmitting your tape deck or CD play er throughout the house, yard or even your car. • Powerful enough for college or neighborhood ra dio stations - in use all ov er the w orld.
P ARTIAL LIST OF AVAIL ABLE KI TS RA MSEY TRA NSM ITT ER KITS • FM25, M P3FM FM Stereo Transmitters • AM1 A M Transmitter • TV6 T elevision Transm itter • FM100 Professional FM Ster eo Tran sm.
FM10A FM STEREO TRANSMITTER Ramsey Pu blication No. MFM10A Manual Price Only: $5.00 TABLE O F CONTENTS Introd uction to the FM10A ........ ............. ............ ...... 4 FM10A Circuit Descrip tion ........ ............... .............. .. 5 Sche matic Di agra m .
INTR ODU C TION The Ram sey FM10A is a true STER EO FM broadcast transmitter, w hich any person may bu ild an d use in accordance with the rules of y our nation’s telecomm unications au thority. For U.S. r esidents, that author ity is the Federal Communications Commission (FCC).
CIRCUIT DESCRIPTION A quick glance at the Schematic Diagram show s that the custom FM stereo transmitter IC (U1) is at the hear t of the FM10A. The control of U1 is determined by its surrounding circuitr y . Potentiometers R1 and R4 allow for adjustment of input leve l.
PA RTS LIST CAPACITORS 4 10 pf disc capacitor (marked 10 or 10K) (C7,8,14,15) 1 18 pf disc capacitor (marked 18) (C16, see note below ) 1 22 pf disc capacitor (marked 22) (C16, see note be.
REQUIRED, NOT SUPPLIED: 9-volt alkaline or heavy -dut y battery Shielded stereo audio cables Line-lev el output au dio sou rce (suc h as a tape deck or CD pla yer) External antenna, small gauge coax and RCA plug, OR PC board mounted telescoping whip ante nna (included with the Ramsey CFM case and knob set.
ASSEMBLY INSTRUCTIONS Building your FM10A Stereo T ransmitter The following FM10A step-by -step assembly and adjustment directions are written with newcomers in mind.
• SOLDER ALL wires or pi ns of th e part, whether t he t wo wires of a resistor or the 18 pins of an IC socket. • Nip or "trim" all excess wires extending bey ond each solder connection, taking care that w ire trimm ings do not be come lodged in PC board solder conn ections.
Wiring the audio input circuits We encourage you to peek at the schematic diagram and learn the functions of the following parts. Howeve r, the sequence of installation is in the order of convenience and speed. If y ou wish, insert the parts groupings as one operation, then solder and nip all connections.
17. Install glass bead diode D1. 18. Install glass bead diode D2. 19. Install glass bead diode D3. 20. Install R7, the small yellow trimmer potentiome ter marked "104". 21. Install C19, the 470 µF electrolytic. Be sure to position for correct polarity .
35. Install R1 0, 10K ohm s [bro wn-black-orange]. The following t wo capacitors have the identical functions of coupling the RF output from the collector of Q1 to the RF output jack (J3) and also the mounting point provided if you wish to use an on-board whip a ntenna.
FM10A freque nc y range selection Capacitor C16 sets the frequency r ange of the FM10A. Values for C16 are as fo llo ws : Desired Transmitter Frequency Range C16 Value Lower end of FM band .......... (88-94 MHz) .... 27 pf Middle portion of FM band ..
ADJUS TIN G YOUR FM1 0 A TRANSMI TTE R Keep all tests very brief until y ou have carefully chosen an open operating frequency in the FM broadcast band.
USING THE FM10A WITHIN THE HOME A most practical use for the FM10A would be to c onnect it to the main stereo system within a la rge home so th at whatever is playing on the main system can also be tuned-in on portable FM ra dios in other rooms, the garage or out in the yard.
negative battery wire. The resistor is omitted if y ou are using a 1.5 volt battery for prolonged short-range operation. EXPERIMENTAL "BROADCASTING" PROJECTS To use the FM10A successfully as.
Although many sources exist for audio mixers, the Radio Shack No. 32 - 1105 is the least expensive commercial device currently available. Bear i n mind that specifications and model numbers for su ch accessory equipment can change from y ear to year.
Ham radio books and m agazines are filled w ith ant enna principl es and ideas which can be adapted to your application. Also, you may wish to loo k at Radio Shack book No.
APPENDIX A: FCC RUL ES AND INFORMATION The Rules of the FCC (Federal Communications Commission) and yo ur kit built FM Stereo Transmitter. An interim explanation of applicable FCC regulations supplied as a personal assistance to FM10A builders, b y Dan F.
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 appea r in the current edition of Part 15. Previous editions of Part 15 discussed "wire less microphones" (such as Ramsey FM-1, FM-4, etc.
space for several different FM statio ns, this is a "generous" limitation designed to a ccommodate cruder FM devices. Properly built and adjusted, the FM10A kit operates w ell with in this li mit. In fact, its signal should sound no "w ider" than any other FM station when listening on an ordinary F M radio.
APPENDIX B: UNDERSTANDING LEGAL "FIELD STRENGTH" A "microvolt" is one-millionth of one volt and designated "µV" in the following explanations. The new FCC Part 15 Rules specify a maximum "Field Strength" of your transmitted signal.
broadcast on a school campus, campgr oun d or local neighbo rhood, as long as you do not cause interference to broadcast reception. “Why talk about acres"? There are three reas ons to transla te our look at "fie ld strength" into "acres".
In fact, the most significant distance in the above chart is the 1.9 µV signal strength permissible at 1260 feet (about 1/4 mile), co vering a cir cular area of about 114 acres. A quick glance at st ereo FM receiver specifications shows typical sensitivity of 1.
4. Check your intended operating frequency ver y carefully, as clearly explained in this instruction m anua l, to ensure yo u will not cause interference to reception of licensed broadcasting. 5. If you receiv e ANY com plaint ab out your trans missions interferin g with broadcast reception, stop or change your operation IMMEDIATELY.
[1] This device may no t c ause harmful interference, and [2] this device must accept any interf erence rece iv ed, including interference that may cause undesired operation. Final comment A well-inform ed person will see to day's FCC Rules to be evolving and progressively less-restrictive.
The Ramsey Kit Warranty Please read carefully BEFORE calling or writing in about your k it. Most problems can be solved w ithout contacting the factory . Notice that thi s is not a "fin e print" w arranty. We want y ou to unders tand your rights a nd ours too ! All Ramsey kits will w ork if assembled p roperly.
Manual Price Only: $5.00 Ramsey Publica tion No. MFM10A Assembly and Instruction manual for: RAMSEY MODEL NO. FM10A FM STEREO TRANSMITTER RAMSEY ELECTRONICS, INC. 793 Canning Parkway Victor, New York 14564 Phone (716) 924-4560 Fax (716) 924-4555 www.ramseyelectr onics.
An important point after buying a device Ramsey Electronics FM10A (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Ramsey Electronics FM10A yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Ramsey Electronics FM10A - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Ramsey Electronics FM10A you will learn all the available features of the product, as well as information on its operation. The information that you get Ramsey Electronics FM10A will certainly help you make a decision on the purchase.
If you already are a holder of Ramsey Electronics FM10A, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Ramsey Electronics FM10A.
However, one of the most important roles played by the user manual is to help in solving problems with Ramsey Electronics FM10A. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Ramsey Electronics FM10A along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
