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Crystal radio amplifier of very high gain needed

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neazoi

neazoi

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Hi,
I have a crystal radio (single diode detector) and I need to amplify the detected audio signal so that it can drive a small speaker or headphones.

The amplifier must have as much gain as possible.
The whole circuit must be made discrete (no opamps) and using as low parts as possible.
Power consumption is not important, simplicity is important.

Is that possible to beat this LM386 using relatively few discrete parts?
How about this http://www.electroschematics.com/8029/1-5-million-high-gain-transistor/
or this one http://www.talkingelectronics.com/projects/HearingAid-2/images/HearingAid-1v5.gif
or figure 6 in this page **broken link removed**

Any ideas?
 
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Most of the simple receivers have about 1uV/m sensitivity at the antenna end and it is tough to improve on that. You will need only a modest gain for a headphone or a small 16R speaker. The diode detector is lousy because it drops too much forward volts to be useful. You can use a handmade detector using a needle and a crystal of lead sulfide. With a good headphone (old style) you can have a radio receiver without using external power.
 

c_mitra said:
Most of the simple receivers have about 1uV/m sensitivity at the antenna end and it is tough to improve on that. You will need only a modest gain for a headphone or a small 16R speaker. The diode detector is lousy because it drops too much forward volts to be useful. You can use a handmade detector using a needle and a crystal of lead sulfide. With a good headphone (old style) you can have a radio receiver without using external power.
Click to expand...

An amplifier is needed, because of lossy antenna posibility or to avoid using high impedance phones.
Any one of the above schematics could provide enough gain and power for the purpose?
 

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