Universal Printed-circuit Board


Quoted from the article:
"The simple square layout makes it easy to cut out. Notice the fat ground bus. This is a big help in achieving stability in RF equipment. In my layouts I usually make any unused board space a part of the ground bus, rather than etch it away. You save etchant and gain stability.

Circle B is the location for a 5/16-inch hole for TV type slug-tuned coils, or a 3/8-inch hole to clear the mounting tabs on compression trimmers. If you allow the tabs to protrude through the board at this point, it's advisable to scrape away the copper foil so the tabs are not grounded. Just a tiny chamfer is sufficient.

Locations A and C are for the leads of compression trimmers. These are usually 25/32-inch apart. By relocating A and C to the right so their center line lies 9/16-inch from the right edge of the board instead of 3/4-inch, and drilling them 7/8-inch apart instead of 25/32-inch you can accommodate the small surplus Erie ceramic trimmers. If you make up boards in advance these holes can be left undrilled so that the board can fit any combination of output parts later."

"Fig 9 shows the mounting of the little Radio Shack transformers. The mounting tabs are pushed through the holes and bent over. It's best to solder one or both tabs to the ground foil. This will result in a quieter circuit. Use 4-40 screws to mount the boards. Spacers can be scrounged from broken rotary switches, switching TV tuners, 1/4-inch OD steel or copper tubing, etc. Keep the input and output sections apart when laying out the boards. If you lay out a multi-stage board, don't use a U-shaped layout! This is asking for trouble. Keep the circuit in a straight line from input to output."

Return to Amateur Radio Receivers || LED Mosfet Receiver || Send E-Mail


Last Update: 05/12/97
Web Author: David White, WN5Y