Science Buddies: "Ask an Expert"

Good afternoon,

After MUCH effort we finally got the radio to work however we only get 1 station 1010 wins and when we move the dial we only get 1010 wins. For a brief moment we were able to get 1 other station 820 (math station). Please help. We have invested DAYS into the project and we feel exhausted and frustrated.

Regards,
exhausted in New Jersey

Mbrennan0424 - Congratulations on getting a working crystal set. The performance of your set is very dependent on several factors. The capability of your antenna/ground system, distance from the AM stations in your vicinity and your location and the transmit power of the stations. The fact that you have found two sites suggests that your set is operating properly. The ability to be selective in tuning is a function of the 'Q' factor of your inductor and the variable tuning capacitor or inductor. There are things you can do to greatly improve this part of your system. You can look up the power output of your radio station on the internet. If your station is WINS on 1010 kHz, the transmitter site is said to be in Lyndhurst NJ. It operates a 50kW transmitter, making it capable of reception over much of the east coast.

This is what may be happening. If you are located within 20 miles of Lyndhurst, this station is virtually saturating your set. Without excellent selectivity, you probably won't hear other faint stations in the background. The other station you received was at 820 kHz, a bit away from the 1010 signal.

I don't think your radio is misbehaving. This might be an opportunity to look into changes you might make to improve selectivity (tuning out unwanted frequencies as you concentrate on receiving others). Good luck.

Rick MArz