Archive for September, 2015

Pastime Projects High Voltage Power Supplies

September 3, 2015

Pastime Projects (www.pastimeprojects.com) manufactures amateur radio kits. Two of our most favorite are the “Remember When” slat board 6V6 kit which was featured in the 1948 (and elsewhere) ARRL Amateur Radio Handbook. This simple transmitter used a 6V6 (or 6L6) vacuum tube on a chassis made of orange crate wood. It was designed for the amateur radio operator to send CW (code) on 80 or 40 meters.
Our more recent kit uses a metal chassis and an improved oscillator kit introduced in the 1960’s Handbooks. It was more stable, easier on crystals, and oscillated on 80, 40 and other bands by switching plug-in coils. Ours uses a 50 ohm link coupled output which matches today’s antennas, antenna tuners, low pass filters, and dummy loads.
These circuits, as first published, were often accompanied by a power supply design which used a 5 volt rectifier vacuum tube. We chose to use modern solid state silicon rectifiers instead. This eliminated the need for a 5 volt winding on the transformer, and the added heat, light, current demand, vacuum tube, tube socket and so
on associated with the rectifier tube.
The result is a simpler less costly power supply for you to build and enjoy. Best regards, Glenn Brown W8JZI for pastimeprojects.com