Ramsey Electronics SA7 manuale d’uso

SA7—1 BROADBAND RF PREAMP ———— 100 KHz - 1.3 GHz • High gain - 2 0 dB Bro adband coverage. • Exce llen t rev ie w in F eb. 90, 73 Ma gazi ne. • Two stage feedback d esign ensures stable o peration. • Runs on 12-15 VDC @ 15 mA . • Com plete with a pplic at ions and hook-up i nstr uction s. Perk up that old receiver! Great fo r sc[...]

SA7—2 SA 7 I N T R OD UC TIO N: A "preamplifier" gives an initial boost, measured in decibels, to the level of a signal before it is processed by tuned circuits, filters, amplifiers, mixers, detectors or other circuit stages. Preamps may be designed for either RF or audi o use and may be either t uned or broadbanded. T he SA7 is indeed [...]

SA7—3 P ARTS SUPPLIED WITH SA7 KI T Capacitors  1 2.2 pF capacitor [axial style, green body with red bands] (C6)  1 4.7 or 5 pF di sc capacitor (C1)  3 .01 uF disc [marked .01 or 103 or 10 nF] (C2,3,5)  1 4.7 to 10 uF electrol ytic capacitor (C4) Resistors  1 47 ohm SMT (surface mount tech nology)"chip" resistor (R6)  [...]

SA7—4 REQUIRED, NOT SU PPLIED  8-15 VDC power source  your choice of powe r on-off switching  RF input and output connectors (your choice of type)  enclosure of your choice, if SA7 is not mounted inside receiver or counter, etc. SA7 layo ut[...]

SA7—5 SA7 PRE-A MP ASSEMB L Y PROCEDURE Soldering 15 parts to a PC board is not a big job, but good performance of the SA7 r equires attention to keeping all leads as short and neat as possible. The order of the parts in stallation is not critical for this and other small kits, so the purpos e of following the suggested order of assemb ly is just[...]

SA7—6  5. Install C5, .01 uF. Notice that C5 lines up with the DC voltage supp ly points on the PC board. If you have y our red (+) and bl ack (-) supply wires ready, they could be installed now while correct polarity is on your mind.  6. Install R4, 1K ohms (brown-black-red) . Note that this r esistor is inst alled vertically, with the res[...]

SA7—7 Installation of C6 and R6. The styl e of these components might be new to you, but don't be concerned. We' ll get them in right. Having inst alled all the conventional re sistors according to color code, note that the remaining resistor-like part is mark ed with 6 bands; the firs t two at one end should both be red. This is the 2.[...]

SA7—8 Procedure for installing SMT R6: 1. Unpack from cardboard protective holder and study how R6 is made, usi ng the magnifier if necessary. 2. Notice that bot h ends are metallic - these are the soldering points. 3. Lightly pre-tin the PC boar d trace point s where R6 is to be positioned. Do not make too h eavy a solder build up. 4. Holding R6[...]

SA7—9 USING YOUR SA7 PRE-A MP The very best way to find out what your S A7 can do, and also cannot do, is to set one up right from the beginning with the input and out put conne ctions most practical for your uses. If you are building it with no specific or "dedicated" use in mind, we suggest that you set up its connec tions to serve as[...]

SA7—10 FINAL NOTES A BOUT BRO A DBAND PRE- A MPS Yes, the Ramsey SA7 or PR2 RF pre- amp will give that prom ised boost to the signal st rength of that distant FM broadcast station that your wife, sist er or dad wants to tune in without so much static. However, if there is a strong local station 20 KHz up or down t he band, reme mber that station [...]

SA7—11 BROADBAND "ACTIVE A NTENN A" For situations where a shor t or indoor receiving antenna is nee ded, the SA7 preamp will give considerably improved performance even if the antenna is little more th an a collapsible whip or sh ort length of wire. For a well-engineered active antenna kit for bot h HF and VHF, at a breakthrough low pr[...]

SA7—12 AN T SA 7 Fr e q . = 6. 28 L x C 1 A d di ng a t uned R F in put[...]

SA7—13 WA R N I N G : Under no circumstances should transmitter power be applied to the SA7. Although this seems common-sense, most receivers are in transceiver configuration and one slip of the mike key will blast your little SA7 to La-La Land.[...]

SA7—14 The Ramsey Kit Warranty Please read carefu lly BEFORE ca lling o r writin g in a bout your ki t. Most pr oblem s can be sol ved w ithout contact ing t he fact ory. Notice that this is not a "fine print" wa rr anty. We want you to understand your rights and ours too! All Ram sey kits will work if assemble d properly. The ve ry fac[...]

SA7—15 Ramse y Electroni cs projec t kits a re packed with pri de in the U SA. If you bel ieve we packed an in correc t part or om itted a pa rt clearly indicated in your assembly manual as supplied with the ba sic kit by Ramsey , please write or call us with information on the part you need and proo f of kit purchase 3. FACTORY REP AIR OF ASSEMB[...]

SA7—16 Published by Ramse y Electronics, Inc. Copyright 1994 All rights reserved. Ramsey Electronics, Inc. 590 Fishers Station Drive Victor, NY 14564 Phone (585) 92 4-4560 Fax (585) 92 4-4555 Call or write for our full line cat alog! RAMSEY TRANSMITTER KITS • FM 10A FM Stereo Transmitter • TV6 Television Transmitter RAMSEY RECEIVER KITS • F[...]