Path: utzoo!telecom-request Date: 15 Apr 91 19:44:05 GMT From: Joshua_Putnam Newsgroups: comp.dcom.telecom Subject: Re: Radio Reception on Telephone Message-ID: Organization: Happy Man Corp., Vashon Island, WA Sender: Telecom@eecs.nwu.edu Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 295, Message 7 of 9 Lines: 52 In sichermn@beach.csulb.edu (Jeff Sicherman) writes: > In article Kyler Laird cc.purdue.edu> writes: >> A friend of mine has a problem with radio reception on his home >> telephone. The FCC told him to use a choke. That's it!? He hasn't >> tried this yet, but I'd like to know what his other options are. >> Also, I'd appreciate knowing the theory behind this. > On the telephone or the manufacturer ? :-) > [Moderator's Note: He could also find out where his high-powered and > probably illegal CB neighbor is located (if that is the type of radio > interference he is getting) and go cut the guy's coax! :) PAT] I've never known anyone with CB interference on the phone, but that may just be luck. Here we always have trouble with AM broadcast stations. Depending on the location of the phone lines, quality of the phone, etc., the talk radio can be as loud as the person on the other end of the line, sometimes louder. The only phones that seem to be immune are our old rotary-dial ones from the dark ages. (No touch-tone in my house :-( The stations are all operating legally, and the phone company used to provide specially-modified phones back before customers could buy their own. (The phones have a capacitor soldered across the speaker terminals.) For more serious cases, a phone line filter is available. The Amateur Radio Relay League (ARRL) Handbook, available in any good library, has a detailed section on interference that includes solutions for phone interference and part numbers for the various filters, chokes, capacitors the phone manufacturers use. Josh Putnam josh@happym.wa.com 206/463-9399 ext.102 Happy Man Corp. 4410 SW Pt. Robinson Road Vashon Island, WA 98070-7399 Moderator's Note: If you want to see a place where AM stations make for bad reception on the radio itself, try an area just outside Wheaton, IL where the transmitters for WGN (720 AM) and WBBM (780 AM) are located about a half-mile from each other. When driving within about a mile on any side of those transmitters, you can tune *nothing* on your car radio but them. Solid WGN signal across the whole AM band for quite a distance, then the same from WBBM for awhile. There is a space in the middle of the two where you get only heterodyne from the two of them together. Listen in sometime if you are driving past! PAT]