Telephone RFI
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Hi everyone,
I have two antennas...an unmatched longwire and a vertical. The unmatched longwire interferes with our two line 900MHz phone system a little bit but the vertical almost destroys audible altogether. While transmitting CW on the vertical, there is a loud clicking sound on both the receiving AND transmitting telephone, even though one or the other could be removed by several miles. The phone line within the building is all CAT-5 with the exception of the last 15' of the base station telephone. I've tried 10 turns of flat 4-conductor telephone cord through a toroid...no difference, (however, I don't know what the toroid is made of). I've tried one of the clamp on decouplers with no change. I can't put a coupling capacitor on the line because of our high speed DSL. It only happens on 40 and 80 meters. There is no interference at 20 meters. Does anyone know who builds telephone RFI filters for this frequency range? I called the local phone company and they said that they don't have anything to do with aircraft frequencies (????). I figured it would be fruitless to pursue this avenue of approach! If I don't get this fixed pretty soon, one of three things will happen: 1. Discontinue use of my K2 between the hours of 0600-2300. 2. Find a solution to this dilemma. 3. Become a priest, because I'll be celibate after this anyway. Thanks in advance Terry de KC0QZX _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Terry,
I have used the KComm telephone filters with great success. The other option you don't mention is to change brands of telephone. When I was having problems, it was with a Bell South portable. The KComm filter cleared up the problem. When the phone eventually gave up the ghost, I switched to a Panasonic and found I no longer needed the filter. Best luck! 73 de Larry W2LJ ----- Original Message ----- From: <[hidden email]> To: "W2LJ" <[hidden email]> Cc: "Elecraft Discussion List" <[hidden email]> Sent: Friday, August 06, 2004 7:08 PM Subject: [Elecraft] Telephone RFI > Hi everyone, > > I have two antennas...an unmatched longwire and a vertical. The > unmatched longwire interferes with our two line 900MHz phone system a little bit but > the vertical almost destroys audible altogether. While transmitting CW on the > vertical, there is a loud clicking sound on both the receiving AND > transmitting telephone, even though one or the other could be removed by several miles. > > The phone line within the building is all CAT-5 with the exception of the > last 15' of the base station telephone. I've tried 10 turns of flat 4-conductor > telephone cord through a toroid...no difference, (however, I don't know what > the toroid is made of). I've tried one of the clamp on decouplers with no > change. I can't put a coupling capacitor on the line because of our high speed > DSL. > > It only happens on 40 and 80 meters. There is no interference at 20 meters. > Does anyone know who builds telephone RFI filters for this frequency range? > I called the local phone company and they said that they don't have anything > to do with aircraft frequencies (????). I figured it would be fruitless to > pursue this avenue of approach! > > If I don't get this fixed pretty soon, one of three things will happen: > 1. Discontinue use of my K2 between the hours of 0600-2300. > 2. Find a solution to this dilemma. > 3. Become a priest, because I'll be celibate after this anyway. > > Thanks in advance > > Terry de KC0QZX > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Wingkeel
Have you investigated RF infiltration into the power line going to the phone
'base' unit rather than into the phone line itself? Ron AC7AC -----Original Message----- I have two antennas...an unmatched longwire and a vertical. The unmatched longwire interferes with our two line 900MHz phone system a little bit but the vertical almost destroys audible altogether. While transmitting CW on the vertical, there is a loud clicking sound on both the receiving AND transmitting telephone, even though one or the other could be removed by several miles. The phone line within the building is all CAT-5 with the exception of the last 15' of the base station telephone. I've tried 10 turns of flat 4-conductor telephone cord through a toroid...no difference, (however, I don't know what the toroid is made of). I've tried one of the clamp on decouplers with no change. I can't put a coupling capacitor on the line because of our high speed DSL. ... Terry de KC0QZX _______________________________________________ _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Wingkeel
Terry -
You could try going back to wired phones. In every case I have tried, wrapping 20 - 30 turns of telephone cord around an old transistor radio ferrite loopstick core (with the original antenna wire stripped off) has been effective. I simply get a 15-20 foot extension cord (pre-made with plugs on each end), wrap it around the core, put some heat-shrink tubing (or plastic electrical tape) over the whole thing to hold the turns in place. Plug it into the phone as near the phone (not the wall) as possible. Usually, I try to arrange things so as to have a pigtail about 3" long at the phone end, and 3 or 4 feet (or whatever is appropriate) for the link to the wall outlet. It really doesn't matter how long the cord on the "wall" side of the filter is, as long as lead on the "phone" side is short. Zap - no RFI, even from my KW, running into a 220' open-wire fed doublet on 160-20 meters. BTW - Multiple layers of phone cord are fine. I usually start with one of the cores that are about 4 or 5 inches long, rather flat in shape, and about 3 or 4 times as wide as they are thick. They look like a flat bar of ferrite. I have also been able to use round cores of the same type, but the flat bars have more ferrite per inch than the round models. Every time I have tried wireless phones, on the other hand, there has been some failing or another that has made me go back to hard wired sets. I even have my DSL connection routed through one of these things, and it runs just fine. Good luck! Jim, KL7CC [hidden email] wrote: >Hi everyone, > > I have two antennas...an unmatched longwire and a vertical. The >unmatched longwire interferes with our two line 900MHz phone system a little bit but >the vertical almost destroys audible altogether. While transmitting CW on the >vertical, there is a loud clicking sound on both the receiving AND >transmitting telephone, even though one or the other could be removed by several miles. > >The phone line within the building is all CAT-5 with the exception of the >last 15' of the base station telephone. I've tried 10 turns of flat 4-conductor >telephone cord through a toroid...no difference, (however, I don't know what >the toroid is made of). I've tried one of the clamp on decouplers with no >change. I can't put a coupling capacitor on the line because of our high speed >DSL. > >It only happens on 40 and 80 meters. There is no interference at 20 meters. >Does anyone know who builds telephone RFI filters for this frequency range? >I called the local phone company and they said that they don't have anything >to do with aircraft frequencies (????). I figured it would be fruitless to >pursue this avenue of approach! > >If I don't get this fixed pretty soon, one of three things will happen: > 1. Discontinue use of my K2 between the hours of 0600-2300. > 2. Find a solution to this dilemma. > 3. Become a priest, because I'll be celibate after this anyway. > > Thanks in advance > > Terry de KC0QZX >_______________________________________________ >Elecraft mailing list >Post to: [hidden email] >You must be a subscriber to post to the list. >Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft >Help: http://mailman.qth.net/subscribers.htm >Elecraft web page: http://www.elecraft.com > > > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Larry Makoski W2LJ
Here are a couple of things to try:
- Try another phone. Radio Shack phones seem to work well around RF - Move the phone to another jack and see if the problem still exists. - Make sure you have a good ground for the ham equipment. - Sometimes adding a length of coax changes the problem. - Do you have the problem if the phone stays in its cradle? Can you operate this phone from the cradle? - Make sure you don't have a poor connection somewhere in the phone system. It may be picking up the rf, and rectifying it. - Unplug nay other phones and try it. - Put ferrite on the coax One time I had a similar problem. It turned out to be a metal clothes line. The turnbuckle rusted. This made a nice diode. The wire picked up the rf, rectified it and reradiated it on multiple frequencies. Good Luck, N2TK, Tony -----Original Message----- From: elecraft-bounces+tony.kaz=[hidden email] [mailto:elecraft-bounces+tony.kaz=[hidden email]]On Behalf Of Lawrence Makoski Sent: Friday, August 06, 2004 7:35 PM To: [hidden email] Cc: [hidden email] Subject: Re: [Elecraft] Telephone RFI Terry, I have used the KComm telephone filters with great success. The other option you don't mention is to change brands of telephone. When I was having problems, it was with a Bell South portable. The KComm filter cleared up the problem. When the phone eventually gave up the ghost, I switched to a Panasonic and found I no longer needed the filter. Best luck! 73 de Larry W2LJ ----- Original Message ----- From: <[hidden email]> To: "W2LJ" <[hidden email]> Cc: "Elecraft Discussion List" <[hidden email]> Sent: Friday, August 06, 2004 7:08 PM Subject: [Elecraft] Telephone RFI > Hi everyone, > > I have two antennas...an unmatched longwire and a vertical. The > unmatched longwire interferes with our two line 900MHz phone system a little bit but > the vertical almost destroys audible altogether. While transmitting CW on the > vertical, there is a loud clicking sound on both the receiving AND > transmitting telephone, even though one or the other could be removed by several miles. > > The phone line within the building is all CAT-5 with the exception of the > last 15' of the base station telephone. I've tried 10 turns of flat 4-conductor > telephone cord through a toroid...no difference, (however, I don't know what > the toroid is made of). I've tried one of the clamp on decouplers with no > change. I can't put a coupling capacitor on the line because of our high speed > DSL. > > It only happens on 40 and 80 meters. There is no interference at 20 meters. > Does anyone know who builds telephone RFI filters for this frequency range? > I called the local phone company and they said that they don't have anything > to do with aircraft frequencies (????). I figured it would be fruitless to > pursue this avenue of approach! > > If I don't get this fixed pretty soon, one of three things will happen: > 1. Discontinue use of my K2 between the hours of 0600-2300. > 2. Find a solution to this dilemma. > 3. Become a priest, because I'll be celibate after this anyway. > > Thanks in advance > > Terry de KC0QZX > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Wingkeel
Years ago I was on the phone with K6NA, we were tuning my
Alpha 76CA up for the 1st time. At about 1300-1400 watts the phone went dead. So did my neighbors phones. The K-Com filters fixed the problem. No more telephone RFI problems....Give em a try.... 73, Art W6KY K1-2 K1-4 Don't forget the CW NAQP Saturday 1800Z to 0600Z Sunday www<dot>ncjweb<dot>com<slash>naqprules<dot>php How's that for 'no HTML' code allowed? [hidden email] wrote: Hi everyone, I have two antennas...an unmatched longwire and a vertical. The unmatched longwire interferes with our two line 900MHz phone system a little bit but the vertical almost destroys audible altogether. While transmitting CW on the vertical, there is a loud clicking sound on both the receiving AND transmitting telephone, even though one or the other could be removed by several miles. The phone line within the building is all CAT-5 with the exception of the last 15' of the base station telephone. I've tried 10 turns of flat 4-conductor telephone cord through a toroid...no difference, (however, I don't know what the toroid is made of). I've tried one of the clamp on decouplers with no change. I can't put a coupling capacitor on the line because of our high speed DSL. It only happens on 40 and 80 meters. There is no interference at 20 meters. Does anyone know who builds telephone RFI filters for this frequency range? I called the local phone company and they said that they don't have anything to do with aircraft frequencies (????). I figured it would be fruitless to pursue this avenue of approach! If I don't get this fixed pretty soon, one of three things will happen: 1. Discontinue use of my K2 between the hours of 0600-2300. 2. Find a solution to this dilemma. 3. Become a priest, because I'll be celibate after this anyway. Thanks in advance Terry de KC0QZX _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Wingkeel
[hidden email] wrote:
> I have two antennas...an unmatched longwire and a vertical. The > unmatched longwire interferes with our two line 900MHz phone system a little bit but > the vertical almost destroys audible altogether. I've had good results with both the KCOM filters and k-y filters <http://www.ky-filters.com/am.htm> (be sure to get the HF model). Also -- this is very important -- if the phone is powered, wind as many turns of the power cable from the wall-wart as you can get onto a toroid or loopstick core. -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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