Catching very low signal

Thread Starter

RBelous

Joined Mar 28, 2021
13
Hello everyone,

sorry, new to electronics and slowly learning.

My questions, how or what can we do to catch very weak and short electromagnetic wave ( in hertz ).

Test subject: 1x1x1 microchip with antenna and LED light, does pass current and works. cannot identify the model or what is the chip.

I tried Rigol DM3058E 5 ½ Digit Digital Multimeter but it does not catch the signal.

The goal is to see catch radio wave emission.

Thanks
 

ronsimpson

Joined Oct 7, 2019
1,681
What radio emissions? What frequency?
You can use a radio to see, measure, RF emissions.

Most volt meters in AC mode will not measure anything above audio frequencies.
 

Audioguru again

Joined Oct 21, 2019
3,873
The effective maximum voltage frequency of the expensive Rigol multimeter is 800kHz which is near the low end of the AM radio broadcast band and a very long antenna is needed.
 

ronsimpson

Joined Oct 7, 2019
1,681
Here is a Spectrum Analyzer. In this picture it is set to see 100khz through 350mhz. You can see a signal at 49mhz and its harmonics. This one will not go below 100khz. This is like radio that scans from one end to the other twice a second. A meter measures everything but these looks at one frequency at a time.
1633820072875.png
There are some Software Defined Radios that will give you the same picture.
 

Thread Starter

RBelous

Joined Mar 28, 2021
13
RonSimpson,

Thank you so much for the respond but a quick question. How can we scan frequency or current in a liquid substance ? can we just plug the wire into the water and try to scan it or it would not work? If I am looking for a signal in an aqueous medium

Here is a Spectrum Analyzer. In this picture it is set to see 100khz through 350mhz. You can see a signal at 49mhz and its harmonics. This one will not go below 100khz. This is like radio that scans from one end to the other twice a second. A meter measures everything but these looks at one frequency at a time.
View attachment 249904
There are some Software Defined Radios that will give you the same picture.
 

MisterBill2

Joined Jan 23, 2018
9,914
You have not even mentioned if the device is a receiver or transmitter. And what units for the dimensions? Inches , millimeters, yards, or furlongs? And if it "works" what does that mean?? That the LED lights? or just that it takes some power?
To detect low power emissions use a sensitive high frequency oscilloscope to look at the signal. If the timebase is accurate you can come close to the frequency.
 

Thread Starter

RBelous

Joined Mar 28, 2021
13
You have not even mentioned if the device is a receiver or transmitter. And what units for the dimensions? Inches , millimeters, yards, or furlongs? And if it "works" what does that mean?? That the LED lights? or just that it takes some power?
To detect low power emissions use a sensitive high frequency oscilloscope to look at the signal. If the timebase is accurate you can come close to the frequency.
Hello,
Thank you for taking your time.
to answer your concerns.
1. receiver or transmitter, I don't know but I believe this small thing will emit a frequency
2.mm
3.that chip has small led indicator and when connected to power adapter it works

Thank you, I have the Rigol multi reader but I am not catching any signal, maybe I am using the wrong machine.
that chip does not look like it connects to anything and so I assume it possible communicate via wireless communication.
 

dl324

Joined Mar 30, 2015
13,574
I tried Rigol DM3058E 5 ½ Digit Digital Multimeter but it does not catch the signal.
A DVM isn't an appropriate tool to catch a transient.

An oscilloscope might be able to, but you'd need a storage function. When I had something interfering with a high frequency SAW oscillator (pulling it off it's resonant frequency), I ended up dangling a wire on the input of a spectrum analyzer. It turned out to be pagers.
 

MisterBill2

Joined Jan 23, 2018
9,914
A 1 x 1 x 1 mm package is incredibly small. If it contains a resonant antenna then the frequency must be in the tens of gigahertz. What do you hope to use it for? even connecting to a package that size is a real challenge.
 

Thread Starter

RBelous

Joined Mar 28, 2021
13
A DVM isn't an appropriate tool to catch a transient.

An oscilloscope might be able to, but you'd need a storage function. When I had something interfering with a high frequency SAW oscillator (pulling it off it's resonant frequency), I ended up dangling a wire on the input of a spectrum analyzer. It turned out to be pagers.
Thank you!
 

Thread Starter

RBelous

Joined Mar 28, 2021
13
A 1 x 1 x 1 mm package is incredibly small. If it contains a resonant antenna then the frequency must be in the tens of gigahertz. What do you hope to use it for? even connecting to a package that size is a real challenge.
Agree, no idea, found it in lab and trying to understand what its for but no way to connect so possible communication via signal transferring.
 

folke2143

Joined Nov 19, 2021
1
Hello, it is best to use the radio to see and measure the RF emissions, then you will know a lot, unfortunately, without it, there is no other way to do it, and the most important thing is what powers the chip
 

KeithWalker

Joined Jul 10, 2017
2,055
So you have some kind of device that has an indicator LED. You state that it has an antenna. Is it just a piece of wire hanging from it or is it a microwave antenna etched on the circuit? Is it encapsulated or just a PC with components mounted on it? Does it incorporate a battery or does it use an external power source? You sure don't give us many clues and without information we have no idea what you are asking about. Why do you think it is even transmitting any kind of electromagnetic signal?
Are you sure this is not connected to some kind of conspiracy theory or a hoax by your fellow workers?
 
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