Ramsey Electronics AA7 инструкция обслуживания

AA7 • 1 ALL BAND HF , VHF , UHF ACTIVE ANTENNA Ramsey Electronics Model No. AA 7 • Great fo r perking up s canner reception. • Dual preamp HF-VHF/UHF front panel s witching. • Circuit based on true active antenna research. • Performance rivals units costing many times more ! • Front panel RF gain contr ol. • Uses Dual Gat e MOSFET te [...]

AA7 • 2 PARTI A L LIST OF A V A IL ABLE KITS RA MSEY TRA NSMIT TER K IT S • FM10, FM25B FM Stereo Transmi tters • FM100 Super Pr o FM Transmitter • MR6 Mod el Rocket Tracki ng Transmitter • AM1 , AM 25 AM Tr a ns m i t te r s RAMSEY RECEIVER KITS • FR1 FM Broa dcast Receiver • A R1 A ircraft Band Receiver • SR2 Shortw ave Receiver ?[...]

AA7 • 3 AA7 ACTIVE ANTENNA KIT Rams ey Publication No. MAA7 Manual Price Only: $5.00 TABLE OF CONTENTS Introduction to the AA7 .................... ................. ........ 4 Circuit and Device Description ....................... ........... 4 Active Antennas: Circuits W ith a Purpose . ............... 5 Parts List .. .................... .....[...]

AA7 • 4 INTR ODU CTI ON TO THE AA7 We believe that you will discover and ag ree with us that your new AA7 is the best VALUE in a true re ceiver antenna. In its s implest form, an “act ive antenna” is a small ante nna going throug h an RF pr eamplifier to a receiver. Generall y , the ac tual ant enna ma y be of several diff erent styles: • b[...]

AA7 • 5 The dual-g ate MOSFET amp lifier circuit (Q 1), selected with S1 in the “o ut” position is designated the HF preamp circuit, due to the exce ptionally low noise level of its operation. This is ideal for enhan cing weak C W -SSB signals. This amplif ier perform s the true “a ctive antenna” fu nction of the AA7. The 2SC2 498 amplifi[...]

AA7 • 6 figure of the amplifier circ uit which amplifies the signal from the ante nna rod before it gets to th e receiver's RF input. We mention these things, with no need to get into a lot of engineering detail, just to let you know that "Active Antennas" are a serious topic a mong contemporary re ceiver designers, and that w e di[...]

AA7 • 7  Needle Nose Pliers (RS64-1844)  Small Diagonal Cutters (RS64-1845) ADDITIONAL SUGGESTED IT EMS  Soldering Iron Holder/Cleaner (RS-64-2078)  Holder f or PC Board/P arts (RS64-2094)  Desoldering Braid (RS-2090) ASSEMBLY INSTRUCTIONS The f ollowing assembly step s are given in ac cord with the LEARN-AS- YOU-BUILD philosophy f[...]

AA7 • 8[...]

AA7 • 9 AA 7 PA RTS LAYO UT D IAG RAM[...]

AA7 • 10 • SOLDER ALL wires or pins of the part, whether the 2 wires of a resistor or the 3 or 4 wires of a transistor. • Trim or Nip all excess wires extending beyond each solder connection, taking care that wire trimm ings do not beco me lodged in PC-board solder connections. Soldering the AA7 Printed Circuit Board  1. Install J1, the RF[...]

AA7 • 11  14. Install R3, 100K [brown-black-yellow].  15. If you have co mpleted Steps 4 through 14 correctly, you now have the 4 holes for Q1 surrounded by other parts, mak ing it easy to find! Examin e Q1, the dual-ga te MOSFET. The sch ematic diagram shows why it has 4 leads. Insert Q1 so that the square tab is pointing directly at JMP2,[...]

AA7 • 12  24. BEFORE connecting battery or conducting any tests, PLEASE recheck each of the pr eceding steps, looking es pecially for: • quality of solder conne ctions • correct orientation of Q1 and Q2 • correct orientation of the electrolytic C4 • correct battery wire polarit y • correct values f or resi stors and ca pacitors INITI[...]

AA7 • 13 rather than only a re ceive r or scanner, make sure it is not possible to transmit by accidentally pressing a mike button or CW keyer. Transmitted RF into the AA7 is likely to ruin on e o r both of the transistors. Transisto r Placement Information: Both transistors may be ordered from Ramsey Electronics, but they also may be found at a [...]

AA7 • 14 Unusual oscillations in receiver: So me portable receivers not enclosed in metal cases may break into oscilla tion wh en conne cted to any RF preamplifier. Try reducing the AA7 gain control and make sure good grounds are on the interconnecting coax cables. Receiver overload ing, heterodynes, images: A preamplifier will intensify any prob[...]

AA7 • 15 The Ramsey Kit W arranty Please read c arefully BEFORE call ing or writi ng in abo ut your kit. M ost pro blems can be solved without contacting the facto ry. Notice that thi s is not a "fin e print" warranty. We want you to u nderstan d your rights a nd ours to o! All Ramsey kits w ill work if assemble d properly. The very fac[...]

AA7 • 16 AA7 AC TIV E AN TENN A Quick Reference Page Guide Introduction to the AA7 ................ .................... . 4 Circuit and Device Description ............ .............. 4 Active Antennas: Circuit s With a Purpose . ....... 5 Schematic Diagram .................. .................... .... 6 Parts Layout Diagram ..... ................[...]