Ramsey Electronics 2 1/2 Watt Super Sleuth Audio Amplifier manual

• Audio b ooster amps f or r adios, Walk mans etc. • Replacement amplifiers • High sensi tivi ty long dis tance l iste ning amplif ier f or ‘B ig Ear s upe r sleuth ’ sno opin g! • Mini PA systems • Tel ephone am plif ier s • Intercom systems • Anywhe re som e quic k audio am pli ficat ion to speaker level is need ed Keep several [...]

INTROD UCTI ON TO THE BN9 The BN9 is a high gain miniature am plifier w ith all sorts of possible a pplications, limited only by your imagination. Its s mall size and econo mical pric e make it a useful addition to many projec ts and re- pairs. The BN9 has an amplificat ion gain fa ctor of 3000 with as muc h as 2 1/2 w atts of audio pow er output. [...]

BN9 PARTS LIST ❒ 2 .01µF ceram ic disk capacitor s (C1, C2 ) ❒ 3 4.7µF or 10µF electrol yt ic capa citors (C 3,C4,C 6) ❒ 1 100µF to 500µF elect rolytic capacitor (C5) ❒ 1 220K ohm resistor (red-red- yellow) (R1) ❒ 1 10K ohm resistor (brown-black-orange) (R2) ❒ 1 NPN transis tor, 2N3904 (Q1) ❒ 1 LM380 audio amplifier IC (U 1) +8 t[...]

BN9 PC BOARD ASSEM BLY As you can see this is a fairly simple and straightforward project, but be careful ! Don’t rush and improperly mount a part or leave long lead leng ths on components. As all good technici ans and experimenters know, part s must be mounted f lush to th e P C board. N ot only fo r mechanical strength and looks, but also to pr[...]

ASSEMBLY OF THE BN9 ❒ 1. Orient the circuit board as shown in the Parts Layout Diagram. ❒ 2. Install U1, th e LM-3 80 IC into the P C boa rd, making sure that all 14 pins are in their proper holes. Also note in which direc tion the not ch is or iented in the Parts Layout Diagram. Mak e sure U1 is moun ted in th e same w ay when you sold er it i[...]

The following electrolytic c apacitors are polarize d and must be insert ed with proper orientat ion to the polarity markings . Usually the capac itors are marked wi th a side stripe to indicate the ne gative (-) pin or rarely a plus symbol to indi cate the plus side. NOTE: The Parts Layout Diagram des ignates the holes where the posi tive (+) lead[...]

INIT IA L T ESTS: ❒ 1. Connect up 8 t o 15 volts of DC power. For s i mplicity use a red wire for posit ive (+) and a black wire for negative (-). Wait! check pola rity before sw itching on the supply. ❒ 2. Connect any speaker ranging fr om an impedance of 3 ohms to 45 ohms. Speak ers in the 4 to 8 ohm region are best suited for th is ki t and [...]

MICROPHONE AND A UDIO INPUT CONSIDERATION You may choose almost any transducer to convert soun d int o an electrical signal fo r your BN9. Some of the transduc ers are as follows; ceramic, crystal, dynamic, or even another speaker! You may also use audio from any other source as well (oth er than a zillion w att per channel pow er amp!) G A I N CON[...]

Problem: Output drops out and then bu ilds up again each time volume control is advanced. Solution: You are running w ith too muc h input power. Ch ange circuit for lower gain operation or re- duce input level. Problem: Very strong AC hum. Solution: Input may not be shielded or c onnected proper ly. Check all of your c onnections to make su re you [...]

Solution: Mo torboati ng is a sound like the “putt-put t-putt” of a two cycle motor boat . While it may be a novel idea for a simple kit, it’s not exactly what we have in mind here. This is usually noticed at higher audio levels due to the power drawn from the power source. The power sourc e (such a s a battery) can’t quite deliver the pow [...]

BN9 A PPLICA T ION IDEA S: 1. High s ensitiv ity listenin g dev ice Compon ents required: • Small microphone such as RAMSEY MC1, mini-electret mike. • 5K to 100K potent iometer for volume control. • 10K resistor (brown-black-orange) • .01uf Ceram ic capa citor NOTE: T o make a full-perform ance “bi g ear” li stenin g sy stem, use a snow[...]

2. Intercom Com ponents re quired: • DPDT s witch (m omentary m ost practi cal) • Two 8 ohm speakers • Your choice of enc losures IN OU T Low gai n B N -9 Re mo t e Local 3. Min i pub lic add ress amp lifier Com ponents requ ired: • 8 Ohm PA speaker or horn spea ker • 5K to 100 K Po tentio meter • Electret microphone or other microphone[...]

IN OU T H o rn S p e a k e r Hi g h Ga i n B N- 9 4. A uxiliary amplifier for mini re ceiv ers Compon ents required : • 8 Ohm sp eaker • 5K to 100 K Po tentio meter • 10 ohm resistor To Rece iv e r IN OU T 10 Low gai n B N- 9[...]

P r obe 200V IN OU T 5. Signal Tracer T est Probe Components req uired: • .01uF C eramic ca pacito r rated a t at le ast 200V for tu be ci rcuits • 5K to 100K Potentiom eter • Shielded test probe with ground clip • 8 ohm speaker or earphone OTHER APPLIC ATIONS With a little ingenuity you c an use the preceding setups to custom design your o[...]

The Ra msey Kit Wa rranty Please read c arefull y BEFOR E callin g or wr iting in a bout your kit. Mos t proble ms can be solved without c ontacting th e fac tory. Notic e that t his is no t a "fin e print" w a rrant y . We want y ou to underst and y our rights a nd ours too! Al l Ra msey kits will w ork if assembled properly . The very f[...]

Published by Ra mse y Electronics, Inc. Copyright 1994 All rights reserved. Ramsey Electronics, Inc. 590 Fishers Station Drive Victo r, NY 14564 Phone (585) 924-4560 Fax (585) 92 4-4555 www.ramseykits.com Call or write for our full line cat alog! RA MSEY T R A NSMITT ER KIT S · FM10, FM25B FM Stereo Transmitters · MR6 Model Rocket Track ing Trans[...]