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AA7

 

  

14

 

Unusual oscillations in receiver:

  Some portable receivers not enclosed in 

metal cases may break into oscillation when connected to any RF 
preamplifier. Try reducing the AA7 gain control and make sure good  
grounds are on the interconnecting coax cables. 
 

Receiver overloading, heterodynes, images:

  A preamplifier will intensify 

any problems with selectivity and image rejection due to poor receiver 
design. 
 

ACTIVE ANTENNA COMPARISONS

 

 

   The author of this AA7 instruction manual has conducted extensive side-
by-side comparisons of the AA7 with the Heathkit HD-1424 and MFJ 
Enterprises, Inc. Model 1020A active antennas, both of which have band-
switched tunable preamplifiers as well as an understandably higher selling 
price. If all three units are compared, each using only its on-board whip 
extended to equal heights, the two tunable units do produce a stronger 
signal. We would hope so!  However, attaching about two more feet of wire 
to the AA7's whip resulted in it delivering the strongest signal. Similarly, 
increasing the antenna lengths of the other units resulted in increased signal 
strength. It becomes a question of how much you wish to pay for the shortest 
possible indoor antenna! The AA7's  competition performs well, but we are 
sure you will appreciate the AA7's versatility and budget pricing. 
 

THE AA7'S ENCLOSURE: THE FINISHING TOUCH 

 

   The Ramsey Electronics custom case, panel and knob kit is optional for 
the AA7 as it is for all of our standard major PC-board kits.  In it’s case, the 
finished AA7 will be attractive and virtually indestructible, so that the world of 
radio can be at your fingertips wherever you go. Use of our factory enclosure 
also enhances the resale value of your AA7. 
 

A FINAL SUGGESTION

 

 

   A small antenna is most effective whenever it can be outdoors and clear of 
any surrounding metal building structure. You may wish to use a mix of 
personal ingenuity and hardware store/junk-box parts to make a simple 
remote whip that can be quickly mounted on windows, windowsills, balcony 
rails, or handy points on cars, RVs, etc. We hope you will enjoy your AA7 in 
a wide variety of listening and monitoring situations. 
Kit building is FUN!  Ramsey has a wide variety of nifty kits.  Ask for our free 
catalog, where there are plenty more kits ideally suited for you!     

Summary of Contents for AA7

Page 1: ...ludes internal telescopic whip antenna plus auxiliary antenna input jack for jazzing up existing antennas Clear concise assembly instructions carefully guide you to a finished kit that works FIRST tim...

Page 2: ...wave Motion Detector ML Music Lights Kit LC1 Inductance Capacitance Meter RAMSEY AMATEUR RADIO KITS HR Series HF All Mode Receivers QRP Series HF CW Transmitters CW7 CW Keyer QRP Power Amplifiers RAMS...

Page 3: ...pose 5 Parts List 6 Assembly Instructions 7 Schematic Diagram 8 Parts Layout Diagram 9 Initial Tests 12 Using your AA7 12 Troubleshooting Guide 13 Active Antenna Comparisons 14 The AA7 s Enclosure 14...

Page 4: ...If what you want is a great quality active antenna for a whole lot less than others sell it for the answer is obvious The Ramsey AA7 active antenna An active antenna is a compromise between what is id...

Page 5: ...r hooked to a piece of wire The AA7 was designed with reference to research carried out by Ulrich L Rohde and T T N Bucher who co authored Communications Receivers Principals and Design New York McGra...

Page 6: ...7 F to 10 uF electrolytic capacitor C4 RESISTORS 1 100 ohm brown black brown R4 2 100K ohm brown black yellow R3 R6 1 220K ohm red red yellow R2 1 1M ohm brown black green R1 1 10K ohm PC mount poten...

Page 7: ...solder A cardboard box cut so that it is flat tends to work well if you do not have such a surface conveniently available Always use caution operating and storing a hot soldering iron We like to live...

Page 8: ...AA7 8...

Page 9: ...AA7 9 AA7 PARTS LAYOUT DIAGRAM...

Page 10: ...nstall R6 100K brown black yellow next to C3 NOTE Save the extra wires nipped away from C3 R6 and similar parts You will use them to make jumper wires 5 Notice that Q2 the 2SC2498 transistor is instal...

Page 11: ...ts the antenna jack J1 and the receiver jack J2 directly together when in the turned off position Solder all six points of the switch 20 Install receiver jack J2 Solder all four points of the jack 21...

Page 12: ...nice about the AA7 is that using it is simple enjoyable and immediate We have two suggestions that will increase your enjoyment of the AA7 right from the beginning 1 Prepare a reliable coaxial cable w...

Page 13: ...current limiting resistor of about 1K ohm to the closest PC board ground point Note This can be locations such as the black wire of the battery the mounting case of either jack but it CANNOT be the an...

Page 14: ...hs of the other units resulted in increased signal strength It becomes a question of how much you wish to pay for the shortest possible indoor antenna The AA7 s competition performs well but we are su...

Page 15: ...g part problem If you re missing five 10K ohm resistors and received five extra 1K resistors you can pretty much be assured that the 1K ohm resistors are actually the missing 10 K parts Hum m m I gues...

Page 16: ...00 Ramsey Publication No MAA7 Assembly and Instruction manual for RAMSEY MODEL NO AA7 ACTIVE ANTENNA KIT REQUIRED TOOLS Soldering Iron WLC100 Thin Rosin Core Solder RTS12 Needle Nose Pliers MPP4 or R...

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