I remember, as a kid, we had an intercom system in our house. There were several intercoms throughout the house; they were plugged into regular outlets and I assume they operated on a radio frequency. They were very cool-looking; they were very '70s looking. They had faux-woodgrain veneer on them, and yellowed-plastic talk buttons. I always loved messing around with them as a little kid; they seemed like futuristic gadgets. This was around 1990-92 or so.
My parents had one in the house in Missouri. This house had a full basement, and one of the speakers was down in the basement, so it actually did have a purpose. There was one speaker down the hall, where the master suite and one other bedroom was, the speaker in the basement, and a speaker and control unit in the kitchen, which also could be used as an AM/FM radio. When we first moved into the house, we all regarded it as quite a cool novelty. Eventually, it broke down. While it worked, it was mostly used by my mother to call us kids up from the basement.
Hm overly effete version of an adirondack shelter…I have actually winter camped in one with the addition of canvas walls for the open front section. We used to just toss up one of the larger tentsmy dad kept around [he was an inveterate boy scout, was on the council as a camp inspector for decades] and sleep out there when it got too hot in the cottage. [brother and I were hanging out in the tent watching a small black n white tv on an extension cord when we saw the announcement that Elvis had just died. ]
They might have used the mains supply as a carrier wave; a gun club I knew had some of these, and due to the chance that the range building (1000yds away) was on the same phase you could talk to them from the clubhouse.
We’ve got one in our new house - it must have been put in during the 70s, because it looks pretty old and isn’t working. I want to pull the boxes from the wall and patch up the holes, but my husband is a geek and has decided he can totally fix them up so they’re usable. Maybe even to play music through the whole house! :rolleyes: So for now, they stay, unsightly beige boxes by the front door, and in the bedrooms, sunroom, and kitchen. It’s harmless and will give him a fun project… someday.
Our cordless phone set works as walkie-talkies, which is handy. When we were replacing a bathroom fan, we had to test an outlet, so my husband was down at the breaker box flipping switches asking “how about this one” while I had the voltmeter poked into the outlet so I could say “nope, keep trying”.
There’s a working system in my house I just moved into a few months ago. It’s made by NuTone. It looks like there was an earlier system that go replaced by a newer one. It works, and it’s handy for calling the kids to dinner, etc.
My house was built in '95 & has such a system with 7 or 8 stations. It sorta-worked when we moved in. Shortly thereafter I spent a day cleaning contacts & got everything working. Then we haven’t used it since. Doubtless it has since corroded back into mostly not working.
My house is big enough you can’t shout from one side to another & be heard. So wife & I use our cellphones as an intercom when needed. Sounds silly, but it’s a real solution that puts the communication wherever you actually are, not just at some arbitrarily selected spots around the house.
Those things are next to useless. Everyone I know who has them in their house ends up not using them at all after the first few months. Texting will probably make them completely obsolete in short order.
We had those when I was growing up. We had one in the basement, one on the first floor, and one on the second floor. They weren’t much use for talking first floor to anywhere else (you could shout just as easily to get someone’s attention) but they worked great for basement to 2nd floor conversations.
They don’t use the main supply as the as a carrier wave. 50/60 Hz (depending on where you are in the world) is too low to modulate a voice signal effectively. Most of these intercom systems did work over the power lines though. They used a high frequency carrier wave that was superimposed over the power frequency. The power supplies of most things would filter this off as noise, but they could sometimes interfere with other electronic devices in the house. The higher frequency carrier wouldn’t effectively go through a transformer, but (in the U.S. at least) a single transformer typically feeds two or three houses. This meant that if your neighbor had the same type of intercom and set theirs to the same channel as yours, they could eavesdrop on all of your intercom conversations.
ETA: Oh, yeah, and to answer the second part of the OP’s question, we don’t have them now. Our cordless phone has an intercom feature though. Mrs Geek has a handset upstairs by her desk and I have one by my desk. She calls me on the intercom all the time (several times per night on average). I call her on the intercom so infrequently that when I did call her on it a couple of weeks ago she had no idea why the phone was ringing differently.
Yes, we have one. It was an option when I was having my house built in 1999. I have a unit in each bedroom, one in the living room, one in the basement, a smaller unit outside the front door tied into the doorbell, and the main controller in the kitchen.
When someone rings the front doorbell, we hear it throughout the house, and can speak to the person at the front door from any indoor unit. The controller is linked into our entertainment system so we can have ambient music playing throughout the house; really sets the atmosphere when we have guests. It also has a built-in AM/FM radio.
We thought we’d use it all the time, but it really only gets used during parties, or when my wife and I are at different ends and levels of the house and one of us needs something from the other.
If I were building my house now, I probably wouldn’t get one, as it turns out to have been a truly unnecessary expense.