Instruction/ maintenance manual of the product QAMP40 Ramsey Electronics
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QAMP-40 • 1 Ramsey Electronics Model No. QAMP40 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 ri g! This nifty little amp will add some “punch” to any QRP transmitter.
QAMP-40 • 2 P A RTI A L LIST OF A V A IL ABLE KITS RA M SEY T RA N SMIT TE R K ITS • FM10, FM25B FM Stereo Transmi tters • FM100 Super Pro FM Transm itter • MR6 Model Rocket Tracking Transmitt.
QAMP-40 • 3 Ramsey Publication No. MQAMP40 Price $5.00 TABLE OF CONTENTS Introduction to the QAMP40 ........... 4 How it works ............... .................... 4 Parts list .... ....................... .............. 5 Tips and notes .... ......
QAMP-40 • 4 INTR ODU CTIO N The Ram sey QAMP series of QRP power ampl ifiers are com pact 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 w ill switch the unit in and out of the antenna line.
QAMP-40 • 5 PARTS LIST FOR THE QA MP40 QRP POWER AMPLIFIER CAPACIT O RS: 1 100 to 220 µ f electroly tic capacito r [C1] 1 10 µf el ectroly tic cap acitor [C2] 4 .
QAMP-40 • 6 "THE RAMSEY LEARN-AS-YOU-BUILD ASSEMBLY STRATEGY" Take a look at the part s layout diagram . There is quite a lot to the construc tion of the QAMP40. It's easier than it seems once y ou get going, especially after you have installed a few of the "landmark" components.
QAMP-40 • 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 bod y of th e part snugly against the top side (component side) of the PC board.
QAMP-40 • 8 16. In stall diode D4, 1N4002 style blac k epoxy diod e. Check positioning of the banded end. 17. Install jumper JMP2. Use a piece of scrap componen t lead wire bent into a "staple" shape and inserted into the board like a component.
QAMP-40 • 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 part s (R8,9 and C11, 12) form parasitic suppress ion networks across each transistor to suppress any tendency for high frequency oscillation in the power amplifier.
QAMP-40 • 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 pre pare all those part s now for fu rther assem bly .
QAMP-40 • 11 Tin each end w ith 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 o ne more turn through the core, continuing on in the same direction as before.
QAMP-40 • 12 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.
QAMP-40 • 13 3. Connect a dummy load to J1, the amplifier RF output. In a pinch, a light bulb m ay be used - see the section, "Ve rifying RF Power Output." 4. Temporarily install a jumper from the collector of Q3 to ground . 5.
QAMP-40 • 14 VERIFYING TRANSMITTER RF OU TPUT The most important thing to know is wh ether your transmitter is delivering some meas urable and reassuri ng level of RF pow e r. Then y ou can continue on to adding the QRP a mplifier and checking out the w h ole set-up .
QAMP-40 • 15 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 y ou use a wattmeter characterized for the HF .
QAMP-40 • 16 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 m ore than that, recheck the bias setting (see the secti on "INITIAL TESTS").
QAMP-40 • 17 case and hardw are set w i ll give your unit that nice finished look and increase its resale value. These sturdy black instrument cases a r e supplied w ith n eatly lettered front and rear panels, switch knobs, rubber feet and mounting screws.
QAMP-40 • 18.
QAMP-40 • 19 The Ramsey Kit Warra nty Please read carefully BEFORE calling or writing in about your kit. Most problems can be solve d without contacting the factory . Notice that thi s is not a "fine print" w ar ranty. W e w ant you to unders tand your righ ts and ours too ! All Ramsey kits w ill work if assembl ed properly .
QAMP-40 • 20 Q A MP40 20 WATT LINEAR AMPLIFIER Quick Re ference Page Gu ide Introduction to the QAMP40 .......... .4 How it works ........................... ........4 Parts list ................. ........................ .5 Tips and notes .........
An important point after buying a device Ramsey Electronics QAMP40 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Ramsey Electronics QAMP40 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Ramsey Electronics QAMP40 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Ramsey Electronics QAMP40 you will learn all the available features of the product, as well as information on its operation. The information that you get Ramsey Electronics QAMP40 will certainly help you make a decision on the purchase.
If you already are a holder of Ramsey Electronics QAMP40, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Ramsey Electronics QAMP40.
However, one of the most important roles played by the user manual is to help in solving problems with Ramsey Electronics QAMP40. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Ramsey Electronics QAMP40 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
