> My specific issue has to do with ringing on my FXS ports. > > A Northen Telecom Harmony phone (circa 1983) rings normally but when I > connect my newer GE 2.4GHz cordless I never get more than 1/2 ring (it lights up and works fine... just can't get a ring from it). Normally I'd assume that it's a low power issue on the FXS port but with a phone rated at 0.1 REM? > > I do have some strange voltages though.... > > ON-Hook: ~48V DC, 107V AC (this really concerns me...) > Off-hook: ~6V DC, ~12VAC (where the hell is this AC component coming from???) > Ring: 0V DC, ~45V AC > > Suffice it to say that electrically this is completely out to lunch... I'd > like to throw an oscilloscope on the line to see what's what but I'm having trouble finding one. >
That on-hook AC is a real problem "if" the voltmeter is accuate. Couple of things to try.... 1. Go to the demarc, disconnect the in-house wiring and measure the AC component again (only looking towards the telco's CO). 2. Disconnect asterisk and install an ordinary analog phone. Take the phone off-hook and measure the AC. If the value is very small, then the voltmeter is measuring induced AC on the "unterminated" wiring. (The phone being off-hook creates the termination.) Put the phone on-hook and measure again. If the value is large, then go looking for the source of the induced AC. Things like wall-warts, fluorescent light ballasts, any device with a transformer in it, electric motors (of some fairly large size), desktop high intensity lamps (with internal transformer), etc, can cause inducedAC "if" they are within inches of the wiring. Using a scope would be good, but it will only validate the voltmeter results; nothing more. If you're unsure about the quality of the voltmeter, borrow another one from someone and compare the results. _______________________________________________ Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
