Ramsey Electronics PA1 manual

PA-1 • 1 2 METER RF POWER AMPLIFIER KIT Ramsey Electronics Model No. P A 1 • Work s with a ny ra dio; m obile , fixed or han dheld • 8 to 10 tim es the po wer gain: 10 watt s out for e very 1 watts in, 20 watts out for every 2 w att s in, 30 w att s out for every 3 w atts in! • Easy c onnecti on to a r adio • Operat es on 12 - 14 volt s D[...]

PA-1 • 2 P ARTIAL LIST OF AVAIL ABLE KITS RA MSEY T RA NSMIT T ER KI TS • FM10, FM25B FM Ster eo Transmitter s • FM100 Super Pr o FM Transmi tter • MR6 Model Rocket Track ing Transmitter • AM1, AM25 AM Transmitter s RAMSE Y RECEI VER KI TS • FR1 FM Broa dcast Receiver • AR1 A ircra ft Band Receiver • SR2 Shortwa v e Recei ver • HF[...]

PA-1 • 3 2 METER RF POWER AMPLIFIER KIT Ramsey Publication N o. PA1 Price $5.00 TABLE OF CONTENTS Kit Building Tips ......................... ...... 5 Parts list ............. ................. ............. 5 Assembly .. ................. ................. ...... 6 Parts Layout Diagram ................ ...... 6 Schematic Diagram ................[...]

PA-1 • 4 PA1 AMPLIFIER All of us at Ramse y say T HANKS for yo ur interest in building the world's most popular 2 Meter amplifier pr oject. Successful construction and installation of your PA1 amplifier can give your handheld 2 Meter transceiver an RF power boost b eyo nd the performance of many fixed and mobile units. BEFORE you begin bu il[...]

PA-1 • 5 KIT BUILDING TIPS Use a good soldering t echniqu e - let your solderin g iron ti p gentl y heat the traces to which you ar e solder ing, heatin g both wires and pads sim ultaneous ly. Apply the solder on the iron and the pad when the pad is hot enough to melt the solder. Th e finis hed joint shou ld look like a dr op of water o n paper, [...]

PA-1 • 6 ASSEMBLY DIRECTIONS: ❒ 1. Simply EXAMINE the PA1 circuit board. Notice w hich way is up or down in accord with our published drawing. Notice that ALL components are surface-mounted (tack-solde red) to one side of the PC board. There are NO component- mounting holes! ❒ 2. Taking care that your soldering tip is clean , pre-tin all m ou[...]

PA-1 • 7[...]

PA-1 • 8 ❒ 5b. Tack-solder C1, one of the Mica compression trimmer capacitors, using enough he at for a solid, go od connection . ❒ 6. Install C3, the other compression trimmer, j ust like C1. ❒ 7a. Bend the leads of C2, the round trimmer capacitor, at right angles so that it can also sit in a level and flat position. The two leads at one e[...]

PA-1 • 9 ❒ 11a. Using the #18 enameled wire , wind a 5-turn coil f or L3. The inside diameter is also 1/4", the turns s hou ld be close-wound, and the ends should be 1/4-inch long. Using a sm all knife or sandpape r, scrape the insulation from each end, tin the bare ends with solder, and gently bend the ends as needed so the coil sits in i[...]

PA-1 • 10 make a suitable HEATSINK for Q1 and in stall it before proceeding. A piece of heavy aluminum or copper the sam e size as the PA1 circuit board will work fine. Even when securing Q1 to such a heatsink, do not use too much force. Observe the correct orientation o f Q1 on the actual circuit board when mountin g it to t he heatsink. The col[...]

PA-1 • 11 INITIAL TESTING Required for testing: • 1 to 5 watt 2 Meter transmitter or transceiv er. • 12 volt DC power source, 5 amp minimum. • RF wattmeter suitable f or VHF use. • Correct cable s and conn ectors. • 50-ohm 30-50 w att dummy load (use antenna for testing only in accordance with appropriate frequency selectio n, transmiss[...]

PA-1 • 12 TRANSMIT-RECEIVE [" T-R"] SWITCHING CONSIDERATIONS: T-R switching of a single antenna with a 2 Meter transceiver and the PA1 RF amplif ier may be accomplished in an y of these wa ys: • 1. Internal conn ections to you r transceiver, making use of its built-in T-R switching circuit or relay. • 2. External T-R relay controlle[...]

PA-1 • 13 CUSTOMIZING YOUR PA1 INSTA LLATION: Since it's up to you to supply the en closure, connectors and any desired operating conveniences, it's likely that each one of those thousands of PA1s in use today has its own personality. For some good ideas, take a look at "Turn Your HT into a 40W 2M Mobile Rig" b y N8KDD in 73 M[...]

PA-1 • 14 A NOTE FOR EXPERIENCED BUILDERS ON LINEAR OPERATION FOR SSB, AND OTHER EMISSION TYPES: Please undertake this conversion ONLY if you understa nd the theo ry and practice involved. Ot herwise, p lease get h elp from another ham e xperienced in amplifier design. This conversion chang es the power transistor form Class C to "biased on&[...]

PA-1 • 15 PA1 WA RRANTY NOTICE: The PA1 k it is the only item in th e entire Ramsey product line that is not covered under any warra nty. Beca use of the variety of ways in which this kit can be constructed and mounted mechanically , we cannot offer any kit repair service. So, if this kit appears too comple x for your abilities, please return it [...]

PA-1 • 16 PA1 2 METE R RF POWER AMPLIF IER Quick Referenc e Page Guide Kit Building Tips ..................... ........... 5 Parts list .................... ................. ....... 5 Assembly ........ ............. ................. .... 6 Parts Layout Diagram ....................... 6 Schemati c Diagram ..... ................. .... 7 Testing .[...]