Homemade one tube shortwave receiver
Ja! The Deutsche Welle has a good signal tonight!
This is my first one tube shortwave radio. This is a "regen" type radio using one 1T4 tube. The radio tunes the 49 meter shortwave broadcast band. It tunes from about 5.8 to 6.4 mhz. I wanted to tune a larger range, but since I didn't have a vernier system nor room for a bandspread capacitor, I decided to use a narrow tuning range. I have some hand capacitance problems also. That is, the radio changes frequency slightly when I put my hand near the tuning dial. Looks like it is time to get out some shielding.
The front panel is made from a piece of 1/8 inch Garolite®. Garolite® can be cut on a table saw, but sometimes the edges tend to chip, so a fine tooth blade would probably work better.
The base of the radio is a piece of stained 3/4 inch oak. This makes the radio look nicer on the inside. Using wood screws I mounted the components to the board. I then wired according to the diagram.
The batteries consist of one D battery for the filament and five 9 volt batteries wired in series. Not shown in the diagram is a DPST switch to act as a power switch. I understand the batteries, especially the 9 volters last a long time. If you want to run the set on AC, at least the B+ part, my thought is to get three - 12 volt dc wall wart power supplies and connect them in series. With the light load of the radio, the voltage should be somewhere near 45 volts. Let me know if you build one of these sets
73, Dave - N2DS