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| Re: 60 CYCLE HUM ON PHONE LANDLINE (1769743) | |||
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Re: 60 CYCLE HUM ON PHONE LANDLINE |
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Posted by Stephen Bauman on Fri Sep 18 22:37:44 2020, in response to 60 CYCLE HUM ON PHONE LANDLINE, posted by https://salaamallah.com/ on Fri Sep 18 14:35:20 2020. REPLACING SPEAKER PHONE AND CORDIs this a copper landline phone with no power attachment? The phone company provides it's own power on its copper wires to power any of its small equipment like speakerphones. They use lots of batteries at their central office to provide 48 vdc to filter out any ac and provide continuous power, should the need to change for the power company's power to local diesel generators in case of a power failure. Even the ring power is pulsed dc. If you are using a third party phone and/or speakerphone, it's likely they get their power from the wall outlet. Any foreign telephone equipment must have a digital access arrangement (DAA) that protects the phone company line from any equipment attached to it. That DAA should filter out any 60 Hz hum. |
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