Sample Radio Projects by Others

 

These are sample radios you can find on the internet

 

Transistor TRF

This is a tube superhet with spider web antenna coil by Daves Radios

 

 

 

 

 

 


Classic Armstrong superhet design


Typical schematic of a superhet radio


Another radio example – hand built

 

Shortwave superhet schematic

Test Post #2

Dave’s Homemade Crystal Radios


Spider Coils Galore

Hello crystal radio fans. Glad you stopped by today. I always like telling my story. For those that have passed 50, this story will most likely sound familiar. That is, we are yearning to relive our childhood. Well, for a small sum of money I was able to do the same.

A “crystal set” is a radio receiver that requires no batteries, or household electric current to operate. It has no apparent power supply. I will tell you at the end of this article how this radio gets it’s power.

The crystal set was the first radio for broadcast reception. Back then, these radios used a galena crystal (a piece of rock that acted as a semiconductor to recover the audio from radio frequency waves). Since then, the semiconductor diode has replaced the galena in most designs as it is one less thing that the user has to fiddle around with.

Since the crystal set is self powered, headphones are required for listening. This ain’t your son’s ghetto blaster. The sound is quite faint but still easy to hear.