[AMRadio] RE:Telephone Wiring RFI Treatment
Hi Mike, I have had hum in the phone lines here on several occasions. When it shows up, I begin un-plugging devices on the phone line one at a time until I find the source. This has, in the past, found a device that was causing the problem. One time the phone company had to replace the service box on the outside of the house. It was so old the service man could not believe that it still worked! It had screw in fuses for line protection. He ended up replacing the service line from the pole. The worst case I had required me to replace the line that runs underground in a PVC pipe to my workshop. The line came out all wet so I used my shop vac to pull air through the pipe for about 2 hours. When the pipe was dry, I replaced the line and the hum was gone. Good Luck! Bill KA8WTK __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] RE:Telephone Wiring RFI Treatment
Bill, Thanks for the reminder about checking the devices before going into the wiring. Unfortunately, I've done that already. __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] RE:Telephone Wiring RFI Treatment
Hi Mike, The hum on your phone line is most likely caused by a ground somewhere in the system. If you have revently installed wiring, there should be a test jack where the lines come in from outside. Disconnect the plastic plyg from this jack which isolates your inside telephone wiring. Plug a separate phone into this jack and listen. If the hum is there, the problem is outside your home and you shoule call the phone company for service. If it disappears, the problem is inside your house. If you are paying for inside wiring service which you shoule be able to detirmnine from your bill, the phone company service will fix it for free. If you are not paying for service, you will have to find it yourself or pay the price to the phone company to find the problem for you which is not exactly cheap. If you want to find it yourself, oner thing to check is the wall outlets. Remove them from the wall and determine if there is a greenish blue oxide on the connector. This sometimes happens when the connector gets damp from condensation or a leak in the insulation somewhere. If you find this problem, do not bother trying to clean the connector. The problem will return soon. It is better to just replace it with a new one. As far as RFI, there is a very good filter sold by an outfit that advertises in QST. They are expensive and you will probably need one for each phone, bit my experience is that they will solve most problems. You can also go the ferrite bead route on the leads behind the wall or try with one of the larger ferrite units that snaps apart and you then wrap several turns of the cable from the wall to the phone around it and snap it closed. This also work in some instances and are far cheaper that the filters I first mentioned. Good luck and let us know what you find. 73 and Top of the Season to you, John, W4AWM __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] RE:Telephone Wiring RFI Treatment
Please excuse the spelling typos. I just came in from working on my G5RV and checked the mail. Wanted to get the answer back asap. Well, back to the roof. The high SWR was caused by a broken lead where the ladder line connects to the antenna. Could not be seen from the ground. I checked the balun yesterday and was up there ready to replace the whole antenna today. When I pulled it down, I found the problem so I am headed back up there with the trusty Bernz 0 Matic torch. 73, John, W4AWM __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
