Why? In my old apartment I’d hear random snippets of calls on my cordless at random times. One signal came through quasi-regularly to the point of annoying. I have no idea where the originating signal came from, but I could hear one half of a conversation (in Cantonese or Mandarin, I think) so clearly at times, you’d swear he was on an extension in my own place. When that happened I just had to hit the “channel” button on my phone.
If I knew who it was, I’d have let the family know because if I was picking up the signal on my POS phone, than other people probably could too. I assume that’s what the OP’s neighbor was doing. He finally had a good excuse (rather than saying “I heard you talking to your girlfriend”) or more verifiable information as to whose signal it was (“Cop talk? Oh, now I know what neighbor that is.”).
I don’t know, but I think it is highly likely. Your new Vtech phone is digital and encrypted, so there must be another unsecured broadcast, and the 900mhz is the likely culprit.
I glanced through the manuals and did searches on words like “digital” and “spectrum” and couldn’t find anything to confirm or deny that it uses spread spectrum digital.
VTech was the first to offer the new 5.8 GHz Digital Spread Spectrum technology to the consumer cordless home telephone market. 5.8 GHz technology offers you the best available performance when it comes to clarity and security.
Protect yourself from identity theft with digital security—your call is digitized and encrypted, making it nearly impossible for someone to eavesdrop
*
Making it nearly impossible for someone to eavesdrop? Except for some neighbor with a baby monitor.
I’m really thinking that the 900mhz phone in the guest room broadcasts even when not being used. I know it shouldn’t, but I have no other answers.
Without access to that phone I can’t answer definitively, but if the phone is in the base AND not “on,” then logically (I stress that–it doesn’t mean that it is this way) the phone shouldn’t be transmitting–there would be no design logic to having it monitoring the telco line and broadcasting it.
Again, I’m looking at it from the “how would I design it” standpoint, which might have no correlation to the real world. A real-world test with your neighbor’s assistance seems indicated assuming you’re on the kind of terms with him that he’ll go along with it.
From a design standpoint it would make little sense. From an economic standpoint point though, if it was a penny cheaper per unit to build a phone that constantly broadcast whatever was on the line then that is how they would likely build it.
I would reset the 4121. Disconnect the power to the base and remove the batteries from the handset(s) and wait for about 30 seconds. Connect the power to the base. Put the batteries back in the handset and place it on the base to re-initialize.
If you are getting incoming calls, it is not the 900MHz. If it was on and connected to the line, it would look as if it was off-hook to the line. It would have to be connected to the telephone line to be picking up your calls.
If you have an intercom feature on the 900MHz, make sure it is not turned on. This is the only thing I could think of that could be picking up the sounds in the house. But it would not pick up telephone calls.
Baby monitors are notorious for not being built to correct standards. And this usually only causes minor problems. And ususally it’s the other way, in other words, people try to use their cell phones and find they can overhear the baby and the parents in the room.
At different levels of power the transmission and decryption suffers. For instance, CB radios can sometimes be heard on the FM band, though CBs do not broadcast on FM, however they sometimes crossover the harmonic side of the FM band and you’ll hear them.
This also works for wireless phones and baby monitors. People have reported being able to pick up the numbers of a cell phone being dialed from the speakers of their computer. Not the conversation but the number dialed, they can hear the touch tone signals.
It’s also possible to set up your electronics incorrectly and actually broadcast to your neighbors. I used to be able to do this with my old Nintendo NES. I could broadcast the game I was playing for about 10 feet, if I hooked it up the wrong way. So someone on channel 3 in the next room would see me playing.
Encryption should not allow for a wireless call to be heard, but it’s possible to have interference that allows for the call to be relayed to the baby monitor once it has been decrypted on the users end.
Did the neighbor hear BOTH sides of the conversation? Or just your end. If he heard just your end, it could be someone has a bug in your home and it’s transmitting and the bug was picked up by the baby monitor.
If he heard both sides of the conversation, it could be your phone is somehow transmitting signals after decryption.
I think if there was a bug in the house (planted either by the neighbor or someone else) then wouldn’t the neighbor be hearing every noise all of the time?
Here’s another thought, rather than someone having a bug in your house in general, could someone have a bug on your phone line?
You are apparently in law enforcement. Is it conceivable that someone would want to bug your phone?
Nah. With the exception of a few special assignments here and there I’ve worked in the patrol sector my entire career. It’s not like I’m in the intelligence service or anything.
Plus, we hardly ever use our home phone.. The only reason I used it last night was because I had left my cell phone in my car.
My money is stil on him having a VTech baby monitor. Electronics manufacturers make money on quantity. They are likely using the same technology in their phones as in those monitors. His receiver would have the same decryption and scanning chip(s) as yours would.
This is not an uncommon problem. The phone may indeed be operating at 5.8 GHz, but only from the base to the handset. The handset to base may be transmitting in the 900 MHz band, in analog, which would explain your neighbor hearing the conversation, or at least half of it. It isn’t the neighbor’s fault that your phone call comes over his baby monitor.
This is exactly it. The 5.8GHz digital spread spectrum that they advertise the heck out of is for the handset to the base unit. The higher power signal back from the base to the handset is likely 900MHz, analog voice and unencrypted. That would be bad enough but since both sides of the conversation are transmitted by the base, it makes the eavesdropper’s job all the easier.
VTECH has never designed a phone this way with two different modulations and frequencies. I should know having designed a lot of the models. Doing it this way would give you an asymmetric range between the handset and the base which is not what you design for.
It is certainly possible that both the baby monitor and cordless phone have the same chipset from DSPG Inc. and they have become synched together somehow. The spread spectrum makes this unlikely but not impossible.