Table of Contents
Advertisement
Quick Links
40 MTR 20 WATT QRP
LINEAR AMPLIFIER KIT
Ramsey Electronics Model No.
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!
QAMP-40 • 1
QAMP40
Advertisement
Table of Contents
Related Manuals for Ramsey Electronics QAMP40
Summary of Contents for Ramsey Electronics QAMP40
- Page 1 40 MTR 20 WATT QRP LINEAR AMPLIFIER KIT Ramsey Electronics Model No. 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”...
- Page 2 1994 by Ramsey Electronics, Inc. 590 Fishers Station Drive, Victor, New York 14564. All rights reserved. No portion of this publication may be copied or duplicated without the written permission of Ramsey Electronics, Inc. Printed in the United States of America. QAMP-40 • 2...
- Page 3 AND INSTRUCTION MANUAL 40 METER QRP CW POWER AMPLIFIER KIT TABLE OF CONTENTS Introduction to the QAMP40 ... 4 How it works ... 4 Parts list ... 5 Tips and notes ... 6 QAMP40 assembly instructions ... 6 Initial testing ..12 Verifying RF output power ...
-
Page 4: Introduction To The Qamp40
INTRODUCTION The Ramsey QAMP series of QRP power amplifiers are compact 10 to 20 watt RF amplifiers for QRP CW transmitters. These amplifiers are made to be driven by transmitters in the ½ to 2 watt range. Built-in to the power amplifier is a sensitive T-R relay which will switch the unit in and out of the antenna line. -
Page 5: Parts List
CAPACITORS: 100 to 220 µf electrolytic capacitor [C1] 10 µf electrolytic capacitor [C2] .1 µf disc capacitor (marked .1 or 104) [C3,8,10,13] 560 ρf disc capacitor (marked 560 or 561) [C4,7] 330 ρf disc capacitor (marked 330 or 331) [C5,6] .001 µf disc capacitor (marked .001 or 102 or 1000) [C11,12] .01 µf disc capacitor (marked .01 or 103 or 10 nf) [C9] RESISTORS:... -
Page 6: Tips And Notes
Take a look at the parts layout diagram. There is quite a lot to the construction of the QAMP40. It's easier than it seems once you get going, especially after you have installed a few of the "landmark" components. Once these "landmark"... - Page 7 Insert the part, oriented correctly, into its correct holes in the PC board. If helpful, gently bend the part’s wire leads or tabs to hold it in place, with the body of the part snugly against the top side (component side) of the PC board. •...
- Page 8 16. Install diode D4, 1N4002 style black epoxy diode. Check positioning of the banded end. 17. Install jumper JMP2. Use a piece of scrap component lead wire bent into a "staple" shape and inserted into the board like a component. Jumpers act as electronic "bridges"...
- Page 9 30. Install C12, another .001 µf disc capacitor (marked .001 or 102). 31. Install C8, .1µf disc capacitor (marked .1 or 104). These last four parts (R8,9 and C11,12) form parasitic suppression networks across each transistor to suppress any tendency for high frequency oscillation in the power amplifier.
- Page 10 We're almost finished. All we need to do now is install a few remaining parts that have to be handmade - for that "old-world craftsmanship" touch! We'll prepare all those parts now for further assembly. We give you plenty of enameled wire, but if you mess up, you can get a whole 50' spool of it from Radio Shack (278-1341).
- Page 11 Tin each end with solder as before. Tin all the way up to the core body. This winding is the primary of transformer T2. 44. Cut off another length of wire, 8 inches long. Wind 1 turn through the core, loop out 1 inch, twist together and run one more turn through the core, continuing on in the same direction as before.
-
Page 12: Initial Testing
Secondary leads (wound previously) 1 turn with loop then 47. Locate the smaller transformer (T2) and install it snugly on the PC board. 48. Install the larger transformer (T1) into the indicated location on the PC board. 49. Install L1, a 19 turn toroid inductor wound previously. If desired, a small dab of hot melt glue, bathtub sealer, or caulk may be used to secure the toroids. -
Page 13: Verifying Rf Output Power
3. Connect a dummy load to J1, the amplifier RF output. In a pinch, a light bulb may be used - see the section, "Verifying RF Power Output." 4. Temporarily install a jumper from the collector of Q3 to ground. 5. - Page 14 VERIFYING TRANSMITTER RF OUTPUT The most important thing to know is whether your transmitter is delivering some measurable and reassuring level of RF power. Then you can continue on to adding the QRP amplifier and checking out the whole set-up. Ideally, you have a small RF wattmeter, already inserted in the antenna line, capable of accurately measuring low output power in watts.
-
Page 15: Troubleshooting Hints
KB4ZGC on how to make a highly accurate yet inexpensive dummy load and wattmeter capable of showing 1/10-watt differences in RF power. If you use a wattmeter characterized for the HF frequency region, it will not give accurate results at the much higher two meter frequencies, although it will be quite adequate for go/no-go testing. -
Page 16: Enclosure Recommendations
check are the bias circuitry and RF path through the relay. The amplifier should draw about ¼ amp with no signal applied. If you see more than that, recheck the bias setting (see the section "INITIAL TESTS"). If you hear an AC hum on the transmitted signal, usual causes are RF getting back into the power supply or a bad VSWR on the antenna. -
Page 17: Parts Layout Diagram
case and hardware set will give your unit that nice finished look and increase its resale value. These sturdy black instrument cases are supplied with neatly lettered front and rear panels, switch knobs, rubber feet and mounting screws. While we believe that the Ramsey enclosure and knob option is a fine value for finishing off your Ramsey kit, we are happy to give you a couple of additional suggestions and our reasons for them. -
Page 18: Schematic Diagram
QAMP-40 • 18... -
Page 19: Ramsey Kit Warranty
'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 believe we packed an incorrect part or omitted a part clearly indicated in your assembly manual as supplied with the basic kit by Ramsey, please write or call us with information on the part you need and proof of kit purchase. -
Page 20: Table Of Contents
Desoldering Braid Ramsey RTS08 • Digital Multimeter Ramsey M133 Price: $5.00 Ramsey Publication No. MQAMP40 Assembly and Instruction manual for: RAMSEY MODEL NO. QAMP40 40 METER 20 WATT LINEAR AMPLIFIER KIT RAMSEY ELECTRONICS, INC. 590 Fishers Station Drive Victor, New York 14564 Phone...
Need help?
Do you have a question about the QAMP40 and is the answer not in the manual?
Questions and answers