Ramsey Electronics QAMP30 manual

QAMP-30 • 1 Ramsey Electronics Model No. QAMP30 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. • W orks great with Ram sey QRP rigs o r any other 1 -2 watt transmitter s • Built-in T/R relay aut[...]

QAMP-30 • 2 RA M SEY T RA N SMIT TE R K ITS • FM100B Professional FM Stereo Transmi tter • FM25B S y nthesized Stereo FM Transmitter • MR6 Model Rocket Track ing Transmitter • TV6 Tele v ision Tra nsmitter RAMSE Y RECEIV ER KITS • FR1 FM Broa dcast Receiver • AR1 A ircraft Band Recei ver • SR2 Shortwa v e Receiver • SC1 Shortwav e[...]

QAMP-30 • 3 Ramsey Publication No. MQAMP30 Price $5.00 TABLE OF CONTENTS Introduction to the QAMP30 ........... 4 How it works .................. ................. 4 Parts list .... ....................... .............. 5 Tips and notes .... ........................... 6 QAMP30 assembly instructions ..... 6 Initial testing ..... ............ ...[...]

QAMP-30 • 4 INTR ODU CTIO N The Ram sey QAMP series of QRP power ampl ifiers are co mpact 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. W hen [...]

QAMP-30 • 5 PARTS LIST FOR THE QA MP30 QRP POWER AMPLIFIER CAPACIT O RS:  1 100 t o 220 µf el ectroly tic capaci tor [ C1]  1 10 µ f elect rolytic c apacit or [C2]  4 .1 µf disc capaci tor ( m arked . 1 or 104) [C3 ,8,10, 13]  2 330 ρ f disc capac itor (marked 330 or 331) [C4 , 7]  2 560 ρ f disc capac itor (marked 560 or 561)[...]

QAMP-30 • 6 "THE RAMSEY LE A RN-AS- YOU-BUILD ASSEMBL Y STRATEGY" Take a look at the parts layout diagram. There is quite a lot to the constru ction of the QAMP30. It's easier than it seems once you get going, especially after you have installed a few of the "landmar k" components. Once these "landmark" componen[...]

QAMP-30 • 7 • If helpful, ge ntly bend the part’s wire lead s 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, whether t he 2 wir es of a resis tor or the 3 or 4 wires of a transistor. • Trim all excess wires extending beyond each s[...]

QAMP-30 • 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 compon ent lead wire bent into a "staple" shape and inserted into the board like a com ponent. Jumpers act as electronic "bridges" carr y ing signals over PC board circuit[...]

QAMP-30 • 9 These last four parts (R8, 9 and C11,12) form parasit ic suppression ne tworks across each transistor to suppress any tendency for high frequency oscill ation in the pow er am plifier.  32. Install C3, another .1 µf disc ca pacitor (m arked .1 or 104). Both of these capacitors by pass the center tap of the ferrite transf or mers t[...]

QAMP-30 • 10 W e 're almost finished. All w e need to do now is install a few remaining parts that have to be handmade - for that "old-wor ld craf tsmanship" touch ! W e'll prepare all those parts now for further assembly . W e give you plen ty of enameled wire, but if you mess up, you can get a w hole 50' spool of it f r[...]

QAMP-30 • 11 amount of wire cut for t his task is the proper amount. If you have too little or too much, then you have not wound the core correctl y . Tin each end with solder as before. Tin all the w a y up to the core body. Th is winding is the primary of transformer T2.  44. Cut off anothe r length of wire, 8 inch es long. Wind 1 turn throu[...]

QAMP-30 • 12  47. Locate the sm aller trans form er (T2) and install it snu gly on th e PC board.  48. In stall the larger tra nsformer (T1) into the indicated location o n the PC board.  49. In stall L1, a 15 turn to roid inductor wound previously. If desired, a small dab of hot melt glue, bat htub sealer, or caulk m ay b e used to secu[...]

QAMP-30 • 13  3. Connect a dummy load to J1, the amplifier RF out put. 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. Apply power to the amplifier but do not turn on the transmitter. Measure the cu rrent drawn by th[...]

QAMP-30 • 14 VER IFYIN G TR ANSM ITTE R RF O UTPU T The most important thing to know is whether your transmitter is delivering some measurable and reassuring level of RF power. Then y ou can contin ue on to adding the QRP amplifier and checking out the whole set-up. Ideally , you have a sm all RF wa ttmeter, already inserted in the antenna line, [...]

QAMP-30 • 15 Amateur radio magaz ine s and handbo ok s provide a varie t y of circuits for RF wattme ters and relative field-strength indicators, in cluding m ethods of using your VOM as an indicating device. CQ magazine for March 1990 offers an article by KB4ZGC on how to make a highly accurate yet inexpen sive dumm y load and w attm eter capabl[...]

QAMP-30 • 16 If you hear an AC hum on the transmitted signal, usual causes are RF getting back in to the power suppl y or a bad VSW R on the ante nna. These short checks in no way detail any and all problems that can rear their ugly head, bu t should get you on the way to solving most errors. We'd like to be able to f oresee a pr oblem a bu [...]

QAMP-30 • 17 W hile w e be lieve that th e Ramsey enclosur e and knob option is a f ine value for finishing off your Ramsey kit, w e are happy to give you a couple of additional suggestions and our reasons for them. If yo ur first goal is economy and rugged portability, you w ill find t hat the circuit board can be mounted nicely in a standard VH[...]

QAMP-30 • 18[...]

QAMP-30 • 19 Amateur radio magazines and handbooks provide a variety of circuits for RF wattmeters and relative field -strength indicators, including methods of using your VOM as an indicating device. CQ magaz ine for March 1990 offers an article by The Ramsey Kit Warra nty Please read carefully BEFORE calling or writing in about your kit. Most p[...]

QAMP-30 • 20 Q A MP30 20 WATT LINEAR AMPLIFIER Quick Re ference Page Gu ide Introduction to the QAMP-30 .......... 4 How it works ........................... ........ 4 Parts list .............. ....................... .....5 QAMP-30 assembly instructions ..... 6 Initial testing .... . ..... ....................... 12 Verifying RF output power ..[...]