View single post by Jan
 Posted: Nov 18th, 2012 03:30 AM
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Jan

 

Joined: Jun 5th, 2012
Location: Inverness, Scotland
Posts: 85
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 Has anyone tried using much newer Schottky diodes rather than germanium? They have a slightly lower forward threshold voltage and insignificant reverse leakage so should be more sensitive. They are what the low-signal crystal set boys are using now I believe.

1N5711, 1N5712 are typical Schottky types and not much more expensive that germanium diodes.

But can someone please explain what these circuits are supposed to do? As far as I can tell, they are just very wide-band RF detectors, any audio component rectified and passed to the audio input of the recording device.

I can see that there is likely to be massive amounts of mains hum induced into the recorder, masking whatever is supposed to be recorded. Apart from adding a high-pass filter, I guess the easiest solution is to record at least a few hundred yards from anywhere with electricity - middle of a field or forest...

Thanks,

Jan