Can anyone tell me what is the proper voltage for a standard residential phone line, and how much variation can cause a problem? I just moved to Las Vegas and my phone is giving me problems. The phone makes three funny tones every time you press the talk button, then proceeds to provide a normal dial tone. Also, the phone displays a message that there is “Parallel set in use” the entire time I am on the phone. I called VTech, and they told me that those two symptoms mean that there is a problem with the voltage of the phone line. OK, so I get my meter out and check both inside the house and at the box outside. Both places read around 50 volts. That’s as far as I’ve gotten because I have no idea what the proper voltage is, and if I did, I wouldn’t know how much variation is acceptable. Can anyone help me out here?
Frank Corley
Edited 10/26/2003 8:59:09 AM ET by francorosso
Replies
Frank,
Normal line voltage is 48V, ring is 96V. Plug your phone up outside at the box to check. Sounds like your phone is the prob. Test with a cheap phone.
KK
Analog phone lines run right at 50 vdc off-line, about 7 or 8 when on line.
There are "line checckers" you can buy (about $20) that can help with this. (No particular recommendation here, but a Hobbes TC-100A is what I have)
Mine will do that when I have voice mail messages, check to see if you have some too.
bake
i'm with bake- sounds like a voice mail/messaging notification tone to me, too.
m
I should have told you to start, it's a different tone than the voice message tone.
Check your off hook voltage. Is the wiring new?
What kind of phone do you have that has a "talk button"?
Sorry, it's an "ON" button, and it's a Vtech gigaphone 2420 base unit and 3 handsets, which worked perfectly until I moved here last week from DC. I know what a voice mail tone is, and this is not it. Also, the message on the phone "Parallel set in use" confirms that there is something going on with my phone line. I also took the phone outside and plugged it into the test jack, and got the same thing - strange tone and a message on the handset.
Parallel set in use means the phone believes the line voltage is too low, like you'd get if another phone was connected and off-hook. Make sure to try it on the interface box on the side of the house with a old regular single-line non-cordless phone. If you get the same odd symptoms, its time for a service call to the phone company. You need to make sure it is the line and not your phone that's the problem or they'll charge you for a service call. A spare regular phone is $5 or $10 at K-mart. you should have one in case of power failures. A service call is $50 plus.
Thanks Bob,
I took the Vtech outside to the box and it did the same thing. Plus, I checked the voltage at the outside box, and it was 50. I bought a corded phone at WalMart for $20 and the corded phone works fine, but that doesn't really mean anything, since the cheap corded phone doesn't give any warning tones, as far as I know. By the way, the Vtech phone works great, it just has the two annoying symptoms I described. I find it hard to believe there is anything wrong with the phone, since it never did anything like this until the very first time I tried to hook it up in my new home.....
The phone company only guarantees that the line will be within certain parameters; i.e. it works with a plain old cord-type telephone. You connect one of those at the test jack, and if it works that's where the telco responsibility ends. Since the Vtech does the same thing inside the house and at the test jack, the house wiring is probably not a suspect. So, it could either be the phone itself or the line. If the line is within limits so the corded phone works right, the phone company would probably say the incoming line is OK. So, my guess would be that your present phone line is different enough in terms of voltage that it spooks your Vtech phone, but the line is technically OK. My feeling is also that the real issue probably lies with the Vtech phone. That's just intuition based on a lot of years of fooling with this stuff. If it's just a little bit bad, it will also probably keep getting a little bit worse. I wouldn't go get a new one unless its under warranty, but I wouldn't be surprised if it developed a more serious fault.
didn;t you know in Vegas you can gamble from home using the tele-touch system?
Yup, when you touch the "talk" button it really means you want to bet.
Press the # key and a menu will prompt you to make a casino selection.
Then you choose craps, bj, baccarat, etc,
Next is the bet amount.
etc.
Have fun.
You can do it anywhere, just have to pay long distant charges. Oh, don't they have toll free numbers? :)
had the same problem with my Vtech when i lived in an apartment earlier this year. We assumed our neighbor had the same phone as they are very popular. When we moved to our house, the phone didn't work with ####new wireless system we had installed (for the computers) so we threw out the Vtech and bought Panasonic's 5.8 Ghz which has been problem free.
Sorry I don't have a solution for you.
My problem consisted of the $2.00 phone cord, ie the cord from the phone jack to the phone/base unit. And don't forget to put Ringbolt Hot Springs, and Boy Scout Canyon on the see and do list, it's just below Hoover dam, one can either hike in or boat/float down or up from Willow beach. Jim J
Frank,
The 50V DC you're measuring is on-hook voltage (i.e., when the phone is hung up). When the phone is off hook, the voltage drops to about 5 volts (DC). That's the voltage that your voice rides on.
It's usually not the on-hook voltage that's a problem for more sophisticated phones, it's the loop current. This is more likely if your house is close to the central office.
The way to check loop current is to put your ammeter in series with the set. Go off-hook (i.e., draw dial tone). Put the meter in the loop. Read the current. Don't leave the meter in the circuit any longer than necessary to get a reading. If you inadvertantly hang up so the set is on-hook and the phone rings, the 90V AC ringing voltage will blow your meter (or at least the fuse in the meter).
Anyway, when the loop current gets much above 30 milliamps, it can cause strange stuff to happen with electronic phones (which these days is just about any phone). The old electromechanical sets were tanks, and 50 mA wouldn't phase 'em.
Before you measure the loop current, I suggest that first you take your phone to another house (not in your immediate neighborhood) and see if it works normally. It could just be damage to the phone in the move. Or it could be that the batteries in the handset are run down, and what you're hearing is a warning tone. If the set works at a dofferent location, check the loop current at your place. If the phone does the same thing, check out the low battery angle in the users manual.
If you do find that the loop current is high, the phone company won't care. There is a fairly low-cost, simple device that you can wire into the line to reduce the loop current w/o affecting the voice transmission. If you need one, e-mail me.
Good luck,
Cliff Popejoy
Thanks,
What do I set the ammeter for when I check the current off loop? I know it isn't batteries, because I have four handsets, each one shows the battery fully charged, and the problem occurs on each handset. Also, the phones have a low battery message and this isn't it. I will try your ideas and get back to you if I need a device to reduce the current.
Frank
Oh, I forgot to ask, besides what setting do I put the ammeter on, how do I put it in series with the line? I'm thinking that this involves more than just touching the ammeter leds to the phone box posts and pushing the "On" button......
Frank
Correct. Put the ammeter ACROSS the line and you'll blow the fuse or fault the phone line. You need a spare phone cord. Strip the jacket someplace in the middle. Take one of the two middle wires (may only have 2). If it has 4 and they have colors, it will be the red or green one. Cut only that one wire and leave the other connected. Strip both ends of that wire. Hook one end to each lead on the ammeter. Plug your modified wire and meter in between the phone and the test jack. Now you're in series with the line and can measure loop current. If you draw any current with the phone ON the hook, you have a problem with the phone or your house wiring. Should only draw current when you take the phone off hook. Unless it rings while you're fooling around. Then you may blow the fuse. 90 volts AC at some reasonable fraction of an amp.