We are organizing a game for students where we are transmitting the daily objectives and hints over from an FM transmitter. Is there a way to limit basic radios to only be able to pick up a certain signal? For instance, 88.3 is not taken in our city, so would have the least amount of interference. We would like to limit it so that the student will dial through the stations (that will all be blocked) until they find the station that actually is broadcasting from a short distance away.
I hope that makes sense 🙂
Best Answer
The radio tuning dial will be some form of a variable component (potentionmeter, variable capacitor). The radio I built had a tuning capacitor attached to the tuning knob.
If you don't want to hot glue the dial in place like Olin suggests, you could turn the dial to 88.3, then remove the variable capacitor and measure its capacitance (probably using an LCR meter). Then replace it with a set capacitor of the read value. The process would be the same if your radio uses a different tuning component, just replace with a set value of that component.