Radio failure

KeithWalker

Joined Jul 10, 2017
3,607
The results from a simple AM receiver circuit like this will depend on what you are using for an antenna and the location of your nearest AM transmitting station. There used to be many stations in the AM band, but now there are only a few.
The amplifier and receiver circuits are both powered by the same DC source so there is a good chance of audio feedback. Connect the radio and the amplifier power input wires directly to the terminals of the supply. If you still get oscillations, put a forward biased (anode to battery +) rectifier diode (1N4001 or similar) in series with the positive supply lead to the receiver and then connect a 100uF capacitor across the receiver power input. This will reduce the possibility of feedback through the supply. Then, with a good antenna, if everything is working, you should be able to turn up the volume far enough to find a radio station.
 

MisterBill2

Joined Jan 23, 2018
27,537
Without an adequate antenna, and probably a ground connection of some kind, you will not receive much on a crystal radio. At least that has been my experience long ago. And if you can not gain a "ground" connection, then another wire run in the opposite direction from the antenna wire.
 

MrChips

Joined Oct 2, 2009
34,817
Your perfboard construction looks very neat and tidy.
I would recommend building experimental circuits first using solderless breadboards. This way you can make changes easily.
 

MrChips

Joined Oct 2, 2009
34,817
Test the speaker amplifier first with audio signal from a source such as a smart phone, tablet, computer, radio, etc.

When you get that working, tell us the strongest and any other AM radio stations in your area.
 

MisterBill2

Joined Jan 23, 2018
27,537
Now I am going to make a really RADICAL suggestion: Stop building for a while and start studying and learning. At some point you will start to understand what is happening with all of those parts in the circuits.

The thrill is almost as great as first learning to read and understand!!! It will be another world opening up for you to visit.
 
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