Synopses & Reviews
Some people think store bought is always better. Even when talking about radios. Some guys think you could never build a regenerative receiver as good as the National's old SW-3, for instance. That's bunk. You should be able to build something every bit as good, if not better. And the ideas needed to do that are here.
First, we start out with a demonstration receiver that will hit you with many ideas, some of which you'll want to try. This receiver is a four tube regenerative with an RF amplifier (TRF). The original configuration uses two audio tubes with audio filter in the back end to drive headphones, but the filter turned out to be more selective than needed. The second version uses a simpler audio filter, and the second audio tube is replaced by a power tube that will drive a loudspeaker to surprising volume. You'll see how a National PW dial drive is mounted upside down for breadboard use, how "plug-in" coil forms are fabricated, and more.
Next, the shortwave converter idea of Vol 3 is taken to next step: a modern tube and a crystal controlled oscillator. When this unit was put in front of the TRF receiver, 15 meter (21 mhtz) amateur band signals came flooding in from all over the planet, loud, stable, and distinct. The two units together with a simple tube transmitter could put you on the higher DX bands.
Then to make tube experimentation easier and larger projects possible, we build a quality power supply capable of providing a wide range of voltages at high current levels.
Finally we explore slide rule dials. These simple, inexpensive fabrications of string and pulleys were used in millions of old broadcast radios, and they worked beautifully. You'll see how one was built from aluminum plate and simple pulleys that could be mounted on a homebuilt receiver. The result is a slow motion dial drive with a long bandspread dial that makes your homebuilt receiver fun to use and will impress the socks off your half-wit relation.