I try to follow this circuit to make an AM radio and the result is just loud distorted noise. Can anyone suggest an idea what is the most important component to make it work? I have some thought probably

1. Antenna?
2. Variable Capacitor?
3. The distance of the radio station? or anything else?

 

In these parts, AM is virtually unusable because of masses of interference from various electronic devices and lighting resulting in loud awful noise. The problem may not be the circuit, but the AM band which is the problem.

 

Could you show how you built it?

 

I vote for the battery as the most important part.

 

Hello,

The schematic is coming from the talking electronics website.
It is the alternative for the larger schematic:



As it said the transformer is from the "super ear" project:



Bertus

 

In these parts, AM is virtually unusable because of masses of interference from various electronic devices and lighting resulting in loud awful noise. The problem may not be the circuit, but the AM band which is the problem.

How can the problem be rectified to get the right signal and get the radio output

 

The PNP transistor in this circuit is biased to have just 0.52V across its base-emitter which means that it will only conduct on one half cycle of the audio - distortion guaranteed.

 

Hello,

@AlbertHall , Yes, the circuits from talking electronics are not always well though/calculated.

Bertus

 

Hello,

@dante_clericuzzio , If you want some more sreious reding about RF technology, have a look at this page:
http://www.radio-electronics.com/info/rf-technology-design/

Bertus

 

Hello,

@dante_clericuzzio , If you want some more sreious reding about RF technology, have a look at this page:
http://www.radio-electronics.com/info/rf-technology-design/

Bertus

Thanks i will read them

 

Place an AM superheterodyne receiver(with 455kHz IF) close to your radio. Tune the super to the the middle of the AM band.

Now adjust your receiver and see if you can detect a quiet spot. If you can......that spot will be 455 high or 455 low of where your RX tuning scale should be.

This test will tell you if the receiver is working half way...and how far off frequency you are.
If you are picking up AM signals and they are distorted....try tuning a little off the sides of the signal.

Having the right test equipment is a worthwhile investment. And it is not near as expensive as it used to be.

 

Place an AM superheterodyne receiver(with 455kHz IF) close to your radio. Tune the super to the the middle of the AM band.

Now adjust your receiver and see if you can detect a quiet spot. If you can......that spot will be 455 high or 455 low of where your RX tuning scale should be.

This test will tell you if the receiver is working half way...and how far off frequency you are.
If you are picking up AM signals and they are distorted....try tuning a little off the sides of the signal.

Having the right test equipment is a worthwhile investment. And it is not near as expensive as it used to be.

Would you mind to suggest are the basic / necessary testing equipment to use in radio frequency testing...example to get the frequency up to 1.8ghz to 2.4ghz