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 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 transmi...
Qamp-40 • 2 partial list of available kits ramsey transmitter kits • fm10, fm25b fm stereo transmitters • fm100 super pro fm transmitter • mr6 model rocket tracking transmitter • am1, am25 am transmitters ramsey receiver kits • fr1 fm broadcast receiver • ar1 aircraft band receiver • sr2 shortwave r...
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 ............................... 6 qamp40 assembly instructions .....
Qamp-40 • 4 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 uni...
Qamp-40 • 5 parts list for the qamp40 qrp power amplifier capacitors: 1 100 to 220 µf electrolytic capacitor [c1] 1 10 µf electrolytic capacitor [c2] 4 .1 µf disc capacitor (marked .1 or 104) [c3,8,10,13] 2 560 ρf disc capacitor (marked 560 or 561) [c4,7] 2 330 ρf disc capacitor (marked 330 or 331) ...
Qamp-40 • 6 "the ramsey learn-as-you-build assembly strategy" 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" c...
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 body of the part snugly against the top side (component side) of the pc board. • solder all wires or pins of the part, whethe...
Qamp-40 • 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" carrying signals over ...
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 parts (r8,9 and c11,12) form parasitic suppression networks across each transistor to suppress any tendency for high frequency oscillation in the ...
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 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' spo...
Qamp-40 • 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 ...
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. 49. Install l1, a 19 turn toroid inductor wound previously. If desired, a small dab of hot melt glue, bathtub sealer, or ca...
Qamp-40 • 13 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. Apply power to the amplifier but do not turn on the transmitter. Measure ...
Qamp-40 • 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, al...
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 you use a wattmeter characterized for the hf frequency region, it will not give accurate results at the much higher two meter frequencies, although i...
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 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 b...
Qamp-40 • 17 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 kno...
Qamp-40 • 18.
Qamp-40 • 19 the ramsey kit warranty please read carefully before calling or writing in about your kit. Most problems can be solved without contacting the factory. Notice that this is not a "fine print" warranty. We want you to understand your rights and ours too! All ramsey kits will work if assemb...
Qamp-40 • 20 qamp40 20 watt linear amplifier quick reference page guide introduction to the qamp40 ...........4 how it works ...................................4 parts list ..........................................5 tips and notes ................................6 qamp40 assembly instructions ........
