GaryM
Veteran Member
Transformers will block wireless intercom signals. They'll also block X-10 signals. They make an interface for X-10 to allow the signals to carry from one side of the transformer to the other.
Evesdropping on phone calls
- Thread starter Spencer
- Start date
- Views: 10000
MossRoad
Super Moderator
- Joined
- Aug 31, 2001
- Messages
- 57,964
- Location
- South Bend, Indiana (near)
- Tractor
- Power Trac PT425 2001 Model Year
When you say wireless, I think RF, as in radio frequency. Here's a link to one at Radio Shack. . A transformer in the AC line would have no affect on an RF intercom as it is only using the AC line for power, not transmitting the signal.
I have an intercom that uses the house AC to transmit the signal. Even though they call it wireless, it isn't, because you have to plug it in. And you are correct, this type of intercom won't go across a transformer, unless you use a bridge module of some type that goes between the two legs in some systems. Same for the X10 stuff that uses the AC line for signal transmission. Here's a link to a bridge at Smarthome.com that uses the electric dryer outlet. You just plug it in.
I have an intercom that uses the house AC to transmit the signal. Even though they call it wireless, it isn't, because you have to plug it in. And you are correct, this type of intercom won't go across a transformer, unless you use a bridge module of some type that goes between the two legs in some systems. Same for the X10 stuff that uses the AC line for signal transmission. Here's a link to a bridge at Smarthome.com that uses the electric dryer outlet. You just plug it in.
GaryM
Veteran Member
Right, when I said wireless I was referring to the ones using the AC line for both power and data. As opposed to the intercoms that use a data connection between the units.
mwechtal
Silver Member
Spencer,
Some other possibilities just came to me.
1) Do you or your wife often talk with someone else that might be in range of their scanner? It could be the phone on the other end that's leaking information.
2) You may have a friend that blabbing to your neighbors.
3) Last year we had a problem with crosstalk in our phone line. I've been told that sometimes when there is crosstalk, only one of the conversations can hear another conversation. This can sometimes be heard by just picking up the phone and listening over the dial tone.
Mike
Some other possibilities just came to me.
1) Do you or your wife often talk with someone else that might be in range of their scanner? It could be the phone on the other end that's leaking information.
2) You may have a friend that blabbing to your neighbors.
3) Last year we had a problem with crosstalk in our phone line. I've been told that sometimes when there is crosstalk, only one of the conversations can hear another conversation. This can sometimes be heard by just picking up the phone and listening over the dial tone.
Mike
MossRoad
Super Moderator
- Joined
- Aug 31, 2001
- Messages
- 57,964
- Location
- South Bend, Indiana (near)
- Tractor
- Power Trac PT425 2001 Model Year
I vote for option 2.
sendero
Gold Member
Most of the possibilities (and a couple I'd never thought of) are well covered - but I would add...
The analog cellular frequency range was restricted in the early 90s, but there are a boatload of scanners that can be modifed by removing one diode or jumper to restore coverage.
If your wife's phone is indeed operating in digital mode, look elsewhere - it is not trivial at all to decode those signals.
The idea of a landline phone pair being accessable by your neighbors is intriging and very very possible. Connecting two wires to a monitor is pretty easy, even the lowest tech person can do it /forums/images/graemlins/smile.gif
Federal courts have ruled (back when 49 Mhz was the hot technology) that users of cordless phones have no "reasonable expectation of privacy". Meaning of course it is quite legal to listen in. I'm not aware of any change in that ruling since the 900/2.4/5.8 phones came out.
In some states, using a parabolic mic is illegal. You could probably find out what the law in your state is somewhere on the net.
Hope you find a clever way to get to the bottom of this, I know it would sure annoy me /forums/images/graemlins/mad.gif
The analog cellular frequency range was restricted in the early 90s, but there are a boatload of scanners that can be modifed by removing one diode or jumper to restore coverage.
If your wife's phone is indeed operating in digital mode, look elsewhere - it is not trivial at all to decode those signals.
The idea of a landline phone pair being accessable by your neighbors is intriging and very very possible. Connecting two wires to a monitor is pretty easy, even the lowest tech person can do it /forums/images/graemlins/smile.gif
Federal courts have ruled (back when 49 Mhz was the hot technology) that users of cordless phones have no "reasonable expectation of privacy". Meaning of course it is quite legal to listen in. I'm not aware of any change in that ruling since the 900/2.4/5.8 phones came out.
In some states, using a parabolic mic is illegal. You could probably find out what the law in your state is somewhere on the net.
Hope you find a clever way to get to the bottom of this, I know it would sure annoy me /forums/images/graemlins/mad.gif
HammerFour
Gold Member
- Joined
- Sep 5, 2002
- Messages
- 297
- Location
- Holt, Missouri
- Tractor
- Kubota B7100, JD Gator 6X4, Kubota L2350, JD 14T Baler, JD 894A Side Delivery Rake, IH 100 Balance Sickle Mower
I used to play with a Radio Shack scanner quite a bit and listen to the police and fire frequencies when I lived in Kansas City, Missouri.
From what I heard all you had to do was remove a diode on that scanner to get access to the 800mhz range to listen to analog cellular calls and it was very easy to do.
If your neighbors have a scanner sitting out, and your wife has an anlog cellular phone, that is probably the culprit.
All they would have to do was set 900 mhz for an upper limit and 800 for a lower limit and let the scanner search the frequencies to find the converstations.
Those scanners would pick up a whole neighborhoods worth of baby monitors and older cordless phones, especially on the optional 8 foot tall antenna you can buy pretty cheaply.
Take care and Happy Holidays!
From what I heard all you had to do was remove a diode on that scanner to get access to the 800mhz range to listen to analog cellular calls and it was very easy to do.
If your neighbors have a scanner sitting out, and your wife has an anlog cellular phone, that is probably the culprit.
All they would have to do was set 900 mhz for an upper limit and 800 for a lower limit and let the scanner search the frequencies to find the converstations.
Those scanners would pick up a whole neighborhoods worth of baby monitors and older cordless phones, especially on the optional 8 foot tall antenna you can buy pretty cheaply.
Take care and Happy Holidays!
Steven
Gold Member
Since 1994 it's been illegal to make or sell scanners that can, or can be easily modified to, pick up calls on the 869-894 MHz sliver of the spectrum where cellular calls ride. But used pre-'94 models are always for sale. This site scanner talks about intercepting phone signals. WOW I guess you never know who may be listening.
I have Bellsouth as my local phone provider and they offer a deal for less than $20.00 a month extra, in addition to the basic plan, where you get unlimited local, in-state and out-of-state long distance, in the continental US. My total bill is less than $75.00 a month, and I have all the bells and whistles. I can talk all day, 24/7 , long distance, and it will never be higher than that. There are several local smaller companies that offer the same for slightly less. I live in south Louisiana.
lamarbur
Gold Member
not thaat it helps this situtation, a few years ago, a very elderly lady was heard throughout the town radio system, in the police car, all the highway trucks,e tc. She blabbed on and on about what relative will receive what, when she passed on. This went on intermitantly for a few hours. Finally, one of her nephews said, talk later aunt Doris.. I had a hunch who it may be and gave her a call. Told her I would be right up there in the pick up. Told her what was going on and she called her new phone provider that re-hooked wiring from AT &T to Sprint.. Sprint was there the day before and Doris' husband at one time was the fire dep't Captain. As such, he had a red phone wiring brought to the house as I had. Sprint tied into that old red phone system and as such, Doris was blabbing her private business all over town. At least, once I figured out who it really was, it was an easy fix at her home.
