My landline will not ring and there is only 45 DC volts going from ATT to my home.

It's my understanding that it should be 48 DC Volts

The 48 volts DC is line voltage, 45 volts is close enough. Ringing voltage is 90 volts plus at 20hz, can't be read with a regular volt meter. What type of phone are you trying to ring and have you tried from the NID?

Sorry, I don't know what an NID is?  The phone system I've used for years is VTech cordless system.  I bought another V-Tech and same thing.  I also bought ATT cordless and same thing, so it's not the phone.  I have a repairman here that is trying to tell me that 45 DC volts is fine to run the system.  My system has for years come from the street to the bow.  From the box to the alarm system and back to the box.  about 120' total.  Then from the box (sining a bypass switch), about 80' to my electronic gate controller then back maybe 80'. Then from the box to my jack in the house 60'?  So the signal has to travel let's say 300-4-- ' before it gets to my landline phone.  The phone will work but does not ring.  I hooked an old style phone to the jack and I get a faint ring.  Nothing has changed in my system for 10 years and all of a sudden it won't ring.

HELP!!

The NID is the box outside, you can google it. Also, as I said the line voltage is 48 VDC, you asked about ringing voltage, which I also gave you. Have the repairman check ringing voltage at the NID. Have them show you the NID and how to test from it. 

so, 90 volts ringing voltage is how many volts DC?

AC is alternating current while DC is direct current… 

Your question is like asking if wall outlet for lamp or tv or pc or toaster is 120 VAC what is the VDC? 

The ringing voltage is AC sine wave sent from the CO when needs to ring…

the suggestion is take the phone and connect at the NID (box on side of house) which by passes all interior wiring, the alarm system, etc… if phone rings at the NID the issue is inside your home including possible the alarm system.

if fails to ring at NID issue is outside for line tech to locate and repair. 

The ringing voltage is AC BUT it's 20hz so you can't read it with a volt meter that only reads the 60hz that normal house voltage is. You'll get a reading but it won't be accurate.

Hi @starrgateBellCanyon, we understand your concern, and let's get the help you need with your landline.

We recommend that you go through our article on how to troubleshoot home phone issues.

Please feel free to reach out to us for further assistance.

Thank you,

Jasmine, AT&T Community Specialist.