Radio Interference on Telephones
- Britny Williams (Unlicensed)
Problem
"I can hear your radio station when I pick up my home telephone receiver."
Solution
It is not uncommon for telephones and their wiring to become unintentional radio receivers. This is especially true for phone lines that run near an AM broadcast site, such as the WHA AM site along Fish Hatchery Road. Sometimes FM and TV signals can also get into phones, but it is much rarer than AM so I will concentrate my advice on the more likely problem.
- Disconnect all phone devices (phones, modems, fax machines, answering machines, etc) on that line, then plug one phone back in and see if the interference is still there.
- If not, plug another device in on the line – keep adding phone devices until you get the interference again. The last device added is the one where the inadvertent radio reception is happening.
- Contact the manufacturer of that device for assistance. If they won’t help, either replace it with a new device that isn’t prone to this problem, or consider trying an add-on radio interference filter.
If all phones that are tried on the line experience the problem, especially if the problem sounds the same on them all, then the point at which the inadvertent radio reception is happening may be elsewhere along the line “upstream” toward the phone company central office. In that case you should contact your phone company’s repair office for assistance. The phone company uses punchdown, crimp connectors which when exposed to the environment can become accidental radio signal detectors. Since the interference is coming into the premises as audio, a radio interference filter is unlikely to help in this situation.
Related Information
Here are some sources for buying radio interference filters. Be sure to specify that you want a filter for the type of signal your phone is picking up: AM broadcast, as opposed to shortwave amateur (ham) radio, versus FM broadcast, and so on.
AT&T also has a filter known as the Z100B1.