User manual RAMSEY FT146

[. . . ] FT146 Here's a simple hard-working transmitter that's ideal for repeaters, Fox-hunts, remote bases, Packet - you name it!Fun and educational to build - you'll be on-the-air in an evening!· · · · · · · · · · Direct, true FM for excellent voice and data quality. Both Data and mike audio inputs Solid 5 watt RF output - add our PA-146 for 40 watts Crystal controlled with 146. 52 MHz crystal included Built-in test points for easy tune-up. [. . . ] Now we call for something unusual - soldering the transistor case to the PC board. Run a neat "flow" of solder around the transistor case to the PC board ground plane. The SD1127 Solder can to PC board power transistor is designed by Solder side of the manufacturer to be soldered board directly to a PC board ground Component side of plane for heat sinking and proper b d VHF performance. This part is different from other metal can transistors in that the case is connected internally to the emitter rather than the collector. This provides much higher gain at VHF frequencies. FT146 · 17 112. Be sure to observe polarity - especially with this part since it is directly across the power supply and if reversed, could overheat so fast, so much that it could explode!Install D5, 1N4002 style black epoxy diode, observe correct orientation of the banded end. Correctly identify the Short lead here cathode side lead which is the Leave leads long R13 shorter of the two. Install the LED, leaving full lead length extending above the board so that the LED can be positioned later into the front panel indicator hole. This allows the use of an Icom/Yaesu/Radio Shack microphone plugged into jack J2. This completes our assembly of the FT146 two meter FM transmitter. Now's a good time to give your masterpiece a good going over, being especially alert for any: · bridged over solder joints, · misplaced components, · transistors or diodes placed incorrectly, · electrolytic capacitors installed incorrectly. TESTING, ALIGNMENT AND ADJUSTMENT To prepare your FT146 for testing, you'll need the following items: 1. Other microphones may be used providing you mate them correctly to the FT146. Since there are such a wide variety of microphone types and styles, we cannot provide exact hook-up wiring for every case. Hook-up is very simple, follow the basic instructions in the "Microphone Considerations" section. If you do not already have a set of plastic or nylon coil alignment tools and do expect to build more ham radio or electronic hobby projects, such tools are worth having and can be found inexpensively at any electronics store including Radio Shack. While a metal Hex key wrench will fit the coil slug, the metal itself will detune the FT146 · 18 coil drastically whenever it is inserted into the coil. You may use a metal hex key if you are aware of this effect and are willing to remove the hex key from the coil after each adjustment. Although not recommended, with a little patience and sandpaper, a useable tool may be formed from a piece of wood or plastic rod. If you do make your own tool, be very careful to fully engage the slug because they are very brittle and any wedging or skewed turning will break it!Small flat blade screwdriver or alignment tool for trimmer capacitors C12, C43, and modulation pot R13. Proper cable to connect from FT146 transmitter (RCA phono) to dummy load. [. . . ] The very fact that your kit includes this new manual is your assurance that a team of knowledgeable people have field-tested several "copies" of this kit straight from the Ramsey Inventory. If you need help, please read through your manual carefully, all information required to properly build and test your kit is contained within the pages!DEFECTIVE PARTS: It's always easy to blame a part for a problem in your kit, Before you conclude that a part may be bad, thoroughly check your work. Today's semiconductors and passive components have reached incredibly high reliability levels, and it's sad to say that our human construction skills have not! [. . . ]