Cheap DIY RF detectors

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Cheap DIY RF detectors

Merializer
I came across a couple of videos some might find interesting:

1) Point contact mixer diode 1N3747 used for DIY RF antenna.
https://youtu.be/xYjEkg7FuM0

2) Simple RF Detector with a detector diode and an LED.
https://youtu.be/vHVmJ5lD9jc
(This person does not believe in EHS, but makes interesting videos, he has a couple more).
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Re: Cheap DIY RF detectors

Fog Top
Very interesting videos, Merializer!  Now I wonder why a plastic German high-frequency analyzer cost me $400?


From: Merializer [via ES] <ml+[hidden email]>
Sent: Sunday, January 12, 2020 8:10 PM
To: Fog Top <[hidden email]>
Subject: [ES] Cheap DIY RF detectors
 
I came across a couple of videos some might find interesting:

1) Point contact mixer diode 1N3747 used for DIY RF antenna.
https://youtu.be/xYjEkg7FuM0

2) Simple RF Detector with a detector diode and an LED.
https://youtu.be/vHVmJ5lD9jc
(This person does not believe in EHS, but makes interesting videos).


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Re: Cheap DIY RF detectors

kjgartner
In reply to this post by Merializer
i actually went looking for that 1N3747 military surplus mixer diode, but I think the only stock comes from people salvaging old equipment.  Amazing how simple the circuit is.  Magic!

My long-term fantasy is that after the election season is over in 2020, we take all those useless lawn signs for candidates and repurpose them into RF meters with red/yellow/green LEDs.  If everyone in a neighborhood had one it would be much more obvious how pervasive those signals are.  The 1N3747 video sparked my hope, but I am not yet handy enough to improvise on this idea.  But some day maybe ...
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Re: Cheap DIY RF detectors

Karl
In reply to this post by Fog Top
Fog Top wrote
Very interesting videos, Merializer!  Now I wonder why a plastic German high-frequency analyzer cost me $400?
The Gigahertz and Cornet meters are supposed to be calibrated; so if you and I both test the field strength around the same microwave while it's running, we should both get roughly the same results - even if my meter is a Cornet and yours is a Gigahertz.

I'm not sure if that's true.  I got some weird readings with my Cornet, and eventually the RF mode stopped working altogether.  It also never told me the frequency of the signals it was detecting, which it's supposed to do.

So maybe having separate antennas for each of the common frequencies and hooking them up to a microamp meter like the one in Merializer's second video* is the way to go.

*They're cheap:  https://www.jameco.com/z/AIM60005-Velleman-Analog-CURRENT-PANEL-METER-50UA-DC-60-X-47MM_315301.html
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Re: Cheap DIY RF detectors

Karl
In reply to this post by Merializer
Here is some more information on designing/building these:

https://www.qsl.net/g3oou/simplerfdetectors.html

https://en.wikipedia.org/wiki/Envelope_detector

I think it would be possible to make a meter with a few of these tuned to different frequencies, and a multi-position knob to switch between them.