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QAMP20 • 1 

Ramsey Electronics Model No.     QAMP20 

 

Need a little extra boost for your QRP rig? Believe it or not, 20 watts is only 
about an ‘S’ unit below a 100 watt rig! This nifty little amp will add some 
“punch” to any QRP transmitter.

 

 

Works great with Ramsey QRP rigs or any other 1-2 watt 
transmitters 

Built-in T/R relay automatically switches between receive and 
transmit                       

Runs on 12 volts DC at 2 to 4 amps; ideal for field day or battery 
operation 

Multistage low pass filter for a clean signal 

Operates all modes: CW, SSB, or AM 

Fast, easy, and fun 2 hour assembly 

Informative manual answers questions on theory, hook-ups, and 
uses - enhances resale value too! 

Clear, concise assembly instructions carefully guide you to a 
finished kit that works the FIRST time! 

 

20 MTR 20 WATT QRP 

LINEAR AMPLIFIER KIT 

 

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Содержание QAMP20

Страница 1: ...elay automatically switches between receive and transmit Runs on 12 volts DC at 2 to 4 amps ideal for field day or battery operation Multistage low pass filter for a clean signal Operates all modes CW...

Страница 2: ...r HR Series HF All Mode Receivers QRP Series HF CW Transmitters CW7 CW Keyer CPO3 Code Practice Oscillator QRP Power Amplifiers RAMSEY MINI KITS Many other kits are available for hobby school Scouts a...

Страница 3: ...ctions 7 Initial tests 12 Verifying RF output power 13 Troubleshooting tips 15 Using the QAMP20 16 Parts layout diagram 17 Schematic diagram 18 Ramsey kit warranty 19 KIT ASSEMBLY AND INSTRUCTION MANU...

Страница 4: ...P amplifier is very simple with most of the magic being done by just a few parts the pair of MOSFET transistors and the ferrite wideband transformers Transformer T2 matches the 50 ohm amplifier input...

Страница 5: ...70 ohm resistors red violet brown R8 9 1 51 ohm resistor green brown black R10 1 2 2 K ohm resistor red red red R11 1 5 K potentiometer marked 502M R4 SEMICONDUCTOR DEVICES 1 Zener diode 6 2 volt gray...

Страница 6: ...the problems we find here at the factory are due to faulty assembly no matter how experienced the builder may be it s especially tough to tell a 30 year experienced ham that he goofed Before you run...

Страница 7: ...RCA phono jacks Solder all 4 pins on each securely as these connectors will be subjected to some stress when coax cables are connected to them 3 Install J3 PC mount DC power jack 4 Install relay K1 N...

Страница 8: ...or proper operation Generally capacitors have their lead marked with a black stripe while PC boards have the hole indicated 22 Install D1 6 2 volt Zener diode gray body with a black band This diode pr...

Страница 9: ...nother 180 f disc capacitor marked 180 or 181 38 Install wire jumper JMP1 Use a scrap piece of component lead wire 39 Locate the MOSFET power transistors and prepare the leads for insertion into the P...

Страница 10: ...t or a magic marker We don t want to confuse it with the other two toroid coils wound just before 43 Winding T2 Locate the smaller of the two 2 hole ferrite cores Cut off one 11 inch length of enamele...

Страница 11: ...le or too much then you have not wound the core correctly Tin each end with solder as before Tin all the way up to the core body 46 Cut off another length of wire 9 inches long Wind 1 turn through the...

Страница 12: ...for testing you ll need the following 1 Multimeter capable of measuring voltage and current 2 12 volt DC power source of at least 3 amp capacity 3 Suitable dummy load and resonant antenna 4 QRP trans...

Страница 13: ...r transmitter with good amateur practice YOUR POWER SUPPLY AND RF OUTPUT POWER For optimum performance one or two volts of extra DC supply power can make quite a difference in any RF power amplifier F...

Страница 14: ...m 2 to 25 volts RMS depending on various factors Typically 1 watt power levels are achieved in the 5 to 7 volts RMS range 5 watts at 12 to 15 volts and 10 watts at 20 to 25 volts A good test bulb for...

Страница 15: ...e for this occurring Any prolonged parasitic emissions may also overheat and destroy other components in the amplifier TROUBLESHOOTING HINTS The QRP power amplifier is very straight forward and simple...

Страница 16: ...r QRP operation and an amplifier is not a band aid for a poor antenna system For maximum performance a QRP station must include the following 1 A resonant antenna dipole or quarter wave vertical 2 Goo...

Страница 17: ...keyer etc The controls are easily mounted at one end of such a box It may be necessary to cut away the molded posts which secure the tape itself These storage boxes come in several styles so pick one...

Страница 18: ...QAMP20 18...

Страница 19: ...h be assured that the 1K ohm resistors are actually the missing 10 K parts Hum m m I guess the red band really does look orange Ramsey Electronics project kits are packed with pride in the USA If you...

Страница 20: ...Quality Electronics Kit was designed and packed in the USA REQUIRED TOOLS Soldering Iron Ramsey WLC100 Thin Rosin Core Solder Ramsey RTS12 Needle Nose Pliers Ramsey MPP4 or RTS05 Small Diagonal Cutte...

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