Double Trace Extension For Vlf Add-On Unit

EE January 1988 onto the board, regulator ICI and power diode D3 are bolted back to back onto a common heat-sink as shown on the component overlay. Do not forget to keep the heat-sink electrically insulated from the metal tab of D3 with the aid of a thick mica washer and a plastic bush. It is possible to use the Type BYV28 diode in position D3. This device is housed in an axial SOD64 enclosure, however, and requires a different mount- ing method than the TO220 style 8R05 from SGS. The BYV28 is mounted up- right, but the anode lead is not bent down until is has been soldered to a cable eye. The eye is then insulated and fitted onto the heat-sink as detailed above. Whatever diode or mounting system is used, check the insulation with a continuity tester! Push the leads of ICI and D3 into the respective holes un- til the heat-sink rests securely onto the board surface. Solder the leads and cut off their excess lengths. Now fit the re- maining components, Li, CI, C6, C7, C8, DI and D2....