# Phone and (extending) answering machine question **URL:** \ **Category:** Factual Questions\ **Created:** [December 10, 2003, 9:30pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202 "2003-12-10T21:30:51Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![cpgoose](https://avatars.discourse-cdn.com/v4/letter/c/258eb7/32.png) [@cpgoose](https://boards.straightdope.com/u/cpgoose)\ **Post date:** [December 10, 2003, 9:30pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/1 "2003-12-10T21:30:51Z")
Hiya…kind of a silly question, but if you have any ideas, that would be cool. Bottom line: my parents have their main phone in the kitchen. I’m referring to it as the main phone because it’s the one that has the answering machine. They never answer the phone, they let the machine get it, and then they decide if they want to answer it based on who’s calling. Sort of an old version of caller-id if you will. (Thanks to all of those telemarketers calling). The only problem is that when they’re upstairs in their bedroom, they can’t hear the answering machine to hear who’s calling. Now, just to give a bit of a wiring background… I added a phone upstairs in their room, coming straight from the main phonebox in the garage. The wires go up through the garage ceiling, and into their bedroom. Then I also added a phone in the basement, and it’s tapped into the phone in kitchen. So, the phone in their room and the one in the basement are indirectly connected, so to speak. My question is whether there would be a way to add a speaker in their room, using their existing phone line, to play what the answering machine is playing? Any ideas? See picture: [http://www.angelfire.com/nj4/cpgoose/phone.gif](http://www.angelfire.com/nj4/cpgoose/phone.gif) ---
**Author:** ![Will\_Repair](https://avatars.discourse-cdn.com/v4/letter/w/a698b9/32.png) [@Will\_Repair](https://boards.straightdope.com/u/Will_Repair)\ **Post date:** [December 10, 2003, 10:23pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/2 "2003-12-10T22:23:14Z")
A speaker tapped off the answering machine would be inexpensive but you’ld have to run wires from the kitchen to the bedroom. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 10, 2003, 10:32pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/3 "2003-12-10T22:32:06Z")
It depends on exactly what you mean by the answering machine (“AM”) “playing”. If the AM is old/dumb, then your parents can simply pick up their upstairs extension phone just after the AM answers, and silently listen to its speil and the response from the caller. No need for any wiring at all. Better if their extension phone(s) have microphone mute buttons so the caller won’t hear any background noise from their phone. Unfortunately, if the AM is newer/smarter, it’ll shut up and hangup as soon as it detects somebody lifting an extension phone. So eavesdropping on the AM won’t work if it’s that kind. If you were trying to have them directly monitor the sounds coming out of the AM’s speakerphone, well then you’d need to connect to the speaker, plus an amp, and wiring from there to separate speakers located near each extension phone. And it’d pretty well have to be on at all times, so it’d function like an intercom. You’d also be hearing noise out of those speakers 24x7, which might not be too good in a bedroom. Yes, you could trigger the amp on and off depending on whether the AM was on or off, but now you’re getting into serious home-brew electronic engineering. Given the question you asked, that sounds like its probably beyond your capability. You _could_ simply run wires from the speaker terminals of the AM to another speaker near the extension phone, skipping the amp, etc. If you used shielded wire it’d work after a fashion. Max volume on the AM might be too quiet at the speakers, and you might still get so much static and buzz that you couldn’t understand what’s being said on the phone. And you would still need to string wire between the two points. You could NOT string two aux speakers for two extension phone off of the AM without using a line-level amp. The impedance situation would be way out of tolerance and you’d end up with almost no volume at any speaker. By the time you built any of these ideas, you’d do a LOT better to simply buy them three phones with caller ID. ---
**Author:** ![Hail\_Ants](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)\ **Post date:** [December 11, 2003, 12:06am UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/4 "2003-12-11T00:06:57Z")
Jeez, just tell them to get Caller ID! :rolleyes: You can get a model which you can program to [say the name of the person who’s calling](http://store.yahoo.com/ahernstore/tcid.html) (after you record it into it). ---
**Author:** ![KP](https://avatars.discourse-cdn.com/v4/letter/k/a9adbd/32.png) [@KP](https://boards.straightdope.com/u/KP)\ **Post date:** [December 11, 2003, 2:07am UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/5 "2003-12-11T02:07:55Z")
I built a circuit that did this perfectly in the 70’s, it used two cheap transistors and a few passive components, and was derived from a common circuit that activated a tape recorder when any handset on the line was picked up. You could probably still buy one at RadShack, and suitable schematics are in any handbook of hobbyist circuits. Total cost would be just a few dollars (hard for me to say exactly: all the parts were very common, and were already in my junkbox) and it would work on the wires you already laid (a big plus!). I do recall that somewhere in the early 80’s (I was an early adopter of home answering machines in the late 70’s) I did have a few glitches on a new machine, but I changed a few resistors for a higher input impedance, and never had a problem after that, I’d suggest getting a book like The Encyclopedia of Electronic Circuits - but I’m sure the circuit is all over the web as well. [This page should give you an idea of what I’m talking about](http://www.ee.washington.edu/circuit_archive/circuits/F_ASCII_Schem_Tel.html) ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 11, 2003, 2:13am UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/6 "2003-12-11T02:13:04Z")
baby monitor? ---
**Author:** ![KP](https://avatars.discourse-cdn.com/v4/letter/k/a9adbd/32.png) [@KP](https://boards.straightdope.com/u/KP)\ **Post date:** [December 11, 2003, 6:56am UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/7 "2003-12-11T06:56:06Z")
Not a bad idea, but baby monitors are routinely picked up by neighbors and scanners. If they make ‘encoded’ versions, they’re probably expensive, and I’d still be skeptical of the encryption. Personally, I’d be very careful using one in the baby’s room during naps (you might forget to shut it off, and have a private conversation). I wouldn’t leave one on 24/7 in a high traffic area, by the main house phone! ---
**Author:** ![cpgoose](https://avatars.discourse-cdn.com/v4/letter/c/258eb7/32.png) [@cpgoose](https://boards.straightdope.com/u/cpgoose)\ **Post date:** [December 11, 2003, 1:41pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/8 "2003-12-11T13:41:51Z")
Acid Kid: Yea, that’s kind of where I was going, it’s just tough to get from the phone to the room upstairs. LSL Guy: Yea, it’s a “smarter” AM, so it would know if the phone was picked up. Hail Ants: I WISH! KP: Thanks, I’ll check out the link. kanicbird: Thanks…hmm…interesting idea. Thanks for all of the ideas. I guess what I was initially thinking was the whole “drag speaker wire to the room”, it’s just tough from where it’s coming from. I guess I was curious if the “sound” that was playing on the AM was also on any of the 4 wires from the phone. In other words, maybe I could tap the wires that are already going into their room for the phone, and use that to get what the AM is saying. Phew, sorry, that was confusing. ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [December 11, 2003, 2:16pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/9 "2003-12-11T14:16:46Z")
> [@](#): > > They never answer the phone, they let the machine get it, and then they decide if they want to answer it based on who’s calling. Sort of an old version of caller-id if you will. This is called “screening calls.” ---
**Author:** ![FatBaldGuy](https://avatars.discourse-cdn.com/v4/letter/f/ecd19e/32.png) [@FatBaldGuy](https://boards.straightdope.com/u/FatBaldGuy)\ **Post date:** [December 11, 2003, 2:45pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/10 "2003-12-11T14:45:18Z")
> [@](#): > > \*Originally posted by cpgoose \* > Thanks for all of the ideas. I guess what I was initially thinking was the whole “drag speaker wire to the room”, it’s just tough from where it’s coming from. I guess I was curious if the “sound” that was playing on the AM was also on any of the 4 wires from the phone. In other words, maybe I could tap the wires that are already going into their room for the phone, and use that to get what the AM is saying. Phew, sorry, that was confusing. \*\* Unless you have two phone lines, only 2 of the 4 wires are being used for the phone, so you could use the extra 2 wires for your speaker. Typically in a phone jack you will have red, green, black and yellow wires. The red and green are used for line 1 and the black and yellow are for line 2, which you could use for your speaker. Another color code sometimes seen is blue with blue/white for line 1 and orange and orange/white for line 2. ---
**Author:** ![cpgoose](https://avatars.discourse-cdn.com/v4/letter/c/258eb7/32.png) [@cpgoose](https://boards.straightdope.com/u/cpgoose)\ **Post date:** [December 11, 2003, 2:56pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/11 "2003-12-11T14:56:58Z")
> [@](#): > > \*Originally posted by Fat Bald Guy \* > \*\*Unless you have two phone lines, only 2 of the 4 wires are being used for the phone, so you could use the extra 2 wires for your speaker. > > Typically in a phone jack you will have red, green, black and yellow wires. The red and green are used for line 1 and the black and yellow are for line 2, which you could use for your speaker. > > Another color code sometimes seen is blue with blue/white for line 1 and orange and orange/white for line 2. \*\* That’s kind of what I was leaning towards, but wasn’t sure if it would work. There’s only 1 phone line. So, if the red and green are being used by the phone, I was curious if I could patch the black and yellow to the AM speaker, and then upstairs in their room, I could attach another speaker to that phone’s black and yellow wires. Would the audio travel indirectly like that? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 11, 2003, 3:23pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/12 "2003-12-11T15:23:52Z")
You could do that, and it may very well work fine, BUT here are the areas to watch out for problems: 1. Make sure you disconnect the black/yellow wires wherever the phone line first enters the house. Ideally put some tag on them which says “do not use because …”. You would not want to leave a weirdly wired booby trap for the phone co (or yourself 10 years from now) if/when a line 2 is installed. Depending on how the phone co has wired things upstream from the house you could also have a problem unless you isolated that pair from their system. They _should_ have it isolated just on their side of the interface, but wiring errors have happened before. 2. Just using those blakc/yello wires could very easily pick up so much hum and static that the remote speaker and the AM’s speaker both were unusable. Or you may find that you can’t get enough volume from both speakers even at full blast on the AM. Or you may find the vclume is so different at the two speakers that you can’t find a volume setting where on’es to oloud and the other too soft. That last problem at least could be corrected with a small 1-3 ohm resistor (ideally an adjustable “trim pot”) in series with the louder speaker. The only way to know how well it works is to give it a whirl. At least it’s pretty easy to try. No great loss if it doesn’t work well enough. It would be desireable to ensure that none of the extension phones are two-line phones. Feeding that audio signal into the phone’s line 2 won’t hurt the phone, but it is another load for the AM’s speaker amp to try to drive and will play hell with the impedance matching. If you do have a 2-line phone, you can effectively convert it to single line by disconnecting one or the other of black/yellow inside the relevant wall outlet, or by using a modular wall-to-phone cord which only has 2 wires. Good luck, let us know how it works out. ---
**Author:** ![FatBaldGuy](https://avatars.discourse-cdn.com/v4/letter/f/ecd19e/32.png) [@FatBaldGuy](https://boards.straightdope.com/u/FatBaldGuy)\ **Post date:** [December 11, 2003, 3:55pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/13 "2003-12-11T15:55:28Z")
Actually, as long as the black/yellow wires are disconnected from the phone line at both jacks, and wired directly to the AM and speaker, you shouldn’t have to worry about any other isolation problems, either at the phone box or other phones. ---
**Author:** ![cpgoose](https://avatars.discourse-cdn.com/v4/letter/c/258eb7/32.png) [@cpgoose](https://boards.straightdope.com/u/cpgoose)\ **Post date:** [December 11, 2003, 4:55pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/14 "2003-12-11T16:55:37Z")
Hmmm, well you say to disconnect the black/yellow wires from where it enters the house (so the phonebox in the garage), but that would be how the AM audio gets from the kitchen to the upstairs…by going through the phonebox in the garage. (See Picture in first post). They’re sort of indirectly connected…you know what I mean? It’s tough to describe. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 11, 2003, 7:26pm UTC](https://boards.straightdope.com/t/phone-and-extending-answering-machine-question/218202/15 "2003-12-11T19:26:35Z")
FBG: look at his diagram, it’s not quite the usual situation. cpgoose: My point was simply to ensure that the black/yellow wires within the house are NOT connected to those which come in from the outside world. It’s a belt-and-suspenders thing, but better safe than sorry. It’ll also help reduce hum. At your “main phone box” in your diagram, just ensure that the line running to the upstairs bedroom and the line running to the rest of the house are connected to each other but not to the black/yellow lugs coming in from outside. You will probably need to splice the wires separately from the way you have the red/green pairs connected, which I assume is just putting both wire runs under the screws at the “main phone box.” Home Depot now sells the special crimp-on splices for phone wiring (“beaners”), but I can’t locate them on their new and improved (ie worthless) website. Lowes has them at [http://www.lowes.com/lkn?action=productDetail&productId=20022-12704-85-900](http://www.lowes.com/lkn?action=productDetail&productId=20022-12704-85-900) or [http://www.lowes.com/lkn?action=productDetail&productId=20666-12704-85-950](http://www.lowes.com/lkn?action=productDetail&productId=20666-12704-85-950). Or you could just solder them together.