«LL -Er S'GFS MOT VAS-ED 53C OHVS all capacitors mot marked afie 0 oq< uf

Fig, 2. Layout of PC Board.

meats can be made. I find it best to draw the layout on the copper side of the board in pencil and then fill in those portions of the circuit board to be retained with the resist paint supplied in the kit. Actually any type of model airplane paint works quite satisfactorily, The pc board is next placed in a small plastic or glass container and covered with the etching solution. (Not used in all kits,) The etching process takes 20 to 30 minutes, during which time the solution should be agitated by rocking the plastic container back and forth. When the etching process is completed the board is washed with water.

f ollowing the etching process the resist paint may be removed with lacquer thinner or carefully scraped from the board. After lhe paint is removed, the board should be cleaned with steel wool or fine sandpaper. After the board is cleaned the resistors and condensers can be mounted as indicated in Fig, 2. The transistors, crystal socket and coils are then mounted. As mentioned previously, the Drain and Source are interchangeable so you don't have to worry how the transistors are installed as long as the Gate is connected to the proper terminal, he transistors require a supply of 12 volts dc. This can be obtained from a small battery pack or a standard 12 volt power supply. The unit requires 18 mA, if intermittent use is contemplated the battery pack will be satisfactory, but if you plan to have the unit on for long periods of time, a standard power supply is suggested. The unit is mounted in a small chassis box

With the unit connected to the receiver, antenna and power supply, the coils can be adjusted for maximum noise in the receiver. This should allow the reception of signals and the coils can be peaked on the receiver "S" meter. In some areas channel 2 may cause some interference. If this is a problem in your area, a tuned circuit consisting of a 45pF trimmer and 5 turn coil V* inch in diameter can be installed between the rf input and the antenna jack to trap out the channel 2 signal. My thanks to Don Bidwell, for his photographs of the converter,

0 0

Post a comment