Modern day phone signal reciever How to do it?

  • #1
I have included a picture of what I would like to be able to make. I know that older phones operate on very specific MHz signals and that the newer ones are 2.4, or 5.8 GHz.
I know there are scanners out there. But the purchase of one could be illegal, right?

So why not make my own, to pick up the signal at my house.

I can see where I would have to find the freq. of my phones here at home.

The phones at my home are wireless, so I would think the voice signals are being sent through the base station out to the other landlines.

Cell phones I imagine would be a more difficult target, I have seen where the freq. Number goes into the ten thousandths place, probably very hard to pinpoint.

With the vast possibilities it would seem that this may be harder than I think, yes?
 

Attachments

  • phone scanner1.jpg
    phone scanner1.jpg
    24.9 KB · Views: 434

Answers and Replies

  • #2
davenn
Science Advisor
Gold Member
2021 Award
9,590
8,689
once upon time you could use a scanner to pick up the old 30 to 40 MHz signals between a cordless phone and its basestation.
These days with the use of the higher frequencies 900MHz, 2.4GHz and 5.8GHz it is more common to use digital and or spreadspectrum techniques between the handset and the base station This makes it somewhere between extremely difficult and impossible to be able to decode and recover any audio from the system. Could probably be done with reasonably sofisticated monitoring equip that some govt agencies have access to.

cheers
Dave
 
  • #3
once upon time you could use a scanner to pick up the old 30 to 40 MHz signals between a cordless phone and its basestation.
These days with the use of the higher frequencies 900MHz, 2.4GHz and 5.8GHz it is more common to use digital and or spreadspectrum techniques between the handset and the base station This makes it somewhere between extremely difficult and impossible to be able to decode and recover any audio from the system. Could probably be done with reasonably sofisticated monitoring equip that some govt agencies have access to.

cheers
Dave

It couldn't be that difficult! Electronics are just pieces of metal and plastic!. Those waves could be picked up by something! The phones themselves can! So the electronics on the phones would be the first thing to look at, right?
 
  • #4
1,763
59
From FCC Rules and Regulations

§ 15.9 Prohibition against eavesdropping.

Except for the operations of law enforcement officers conducted under lawful authority, no person shall use, either directly or indirectly, a device operated pursuant to the provisions of this part for the purpose of overhearing or recording the private conversations of others unless such use is authorized by all of the parties engaging in the conversation.
 
  • #5
f95toli
Science Advisor
Gold Member
3,318
817
It couldn't be that difficult! Electronics are just pieces of metal and plastic!. Those waves could be picked up by something! The phones themselves can! So the electronics on the phones would be the first thing to look at, right?

And how would you "look" at the electronics in a phone?
The days were sophisticated electronics use elementary components such as resistors and transistors are long gone, modern electronics uses ASICs with millions and sometimes billions of components connected together and packad into single chips.
Of course you can get equipment that could do what you want, but you would need to spend hundreds of thousands of dollars (even something a simple as a spectrum analyzer for these frequencies will cost more than $50 000)
 
  • #6
72
1
From FCC Rules and Regulations

§ 15.9 Prohibition against eavesdropping.

Except for the operations of law enforcement officers conducted under lawful authority, no person shall use, either directly or indirectly, a device operated pursuant to the provisions of this part for the purpose of overhearing or recording the private conversations of others unless such use is authorized by all of the parties engaging in the conversation.

This probably needs to be re-posted.
 
  • #7
berkeman
Mentor
62,185
12,962
Thread closed for illegal activity discussion. Flyingwing12 -- check your PMs.
 

Related Threads on Modern day phone signal reciever How to do it?

  • Last Post
Replies
8
Views
6K
  • Last Post
Replies
2
Views
4K
  • Last Post
Replies
1
Views
10K
  • Last Post
Replies
2
Views
2K
Replies
14
Views
3K
Replies
5
Views
13K
Replies
2
Views
1K
  • Last Post
Replies
7
Views
104K
Replies
13
Views
2K
Top