For better results, assemble the circuit on a good-quality glass epoxy board and house the transmitter inside an aluminium case. Shield the oscillator stage using an aluminium sheet.
Coil winding details are given below:
L1 4 turns of 20 SWG wire close wound over 8mm diameter plastic former.
L2 2 turns of 24 SWG wire near top end of L1. (Note: No core (i.e. air core) is used for the above coils)
L3 7 turns of 24 SWG wire close wound with 3mm diameter air core.
L4 7 turns of 24 SWG wire-wound on a ferrite bead (as choke)
In the electrical sector, a schematic diagram is usually used to describe the design or model of equipment. Schematic diagrams are usually utilized for the maintenance and repair of electronic and electromechanical devices / units. Original schematics were made by hand, using standardized templates or pre-printed adhesive symbols, but nowadays Electrical CAD computer software is often used.
In electronic design automation, until the 1980s schematics were virtually the only formal representation for circuits. More lately, using the progress of computer system technology, other representations were introduced and specialized computer languages were developed, because with the explosive development of the complexity of electronic circuits, classic schematics are getting less practical. As an example, hardware description languages are indispensable for contemporary digital circuit design.