ke3nj
join:2007-12-27
Danville, PA
| [trouble] RF Interference causing sync/lost intenet light.
Hi I'm new at DSL. I have a Westell 327W modem/wireless Router. I'm a licensed Amateur Radio Operator. My problem is this: Everytime I key my transmitter on the 160 meter band (1.8-2.0 Mhz) I lose DSL (internet light goes out) It takes about 30-60 seconds AFTER I un-key for the system to recover. I ran shielded pair from the service entrance to the modem. I can remove all the telephones and their wiring from from the DSL line. Power levels as low as less than 10 watts cause this to happen. What really puzzles me is that on 2 occasions, I have been able to Transmit at high power (1000 watts) with no problems. The first time it lasted for all day (7:30 AM to 10:30 PM), the 2nd time was just this morning, it only lasted about 2 hrs. That leads me to believe that there is some type of intermittent problem in the phone line as I have tried 3 different modems with similiar results. I'm reluctant to go inside the Westell 327W as it was provided by Verizon.
Anyone have any suggestions? ke3nj@verizon.net
Thanks, KE3NJ Dave |
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tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
 ·Hollis Hosting
 ·Verizon Online DSL
·Fairpoint Communic..
| Welcome to BBR.
DSL occupies spectrum from 25 kHz - 1100 KHz. That is just below the 160 meter band.
Do you know if problem is caused by radiated noise (leaks or the antenna) or conducted through the power line? If transceiver is on same AC circuit as modem try moving one or the other. If possible to a different AC leg.
What is the difference between running 10 watts and 1000? I assume you are using an amp. Perhaps the raw transmit signal is dirty and the amp cleans it up. Just a thought.
/tom |
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Slidetbone
Mazin Go
Premium
join:2002-11-10
Land O Lakes, FL
| reply to ke3nj
I don't believe the POTS line is the problem. I am taking a stab at this, but most likely there is some oscillator in the modem that is sensitive to the RF or harmonics of your signal when you go on air, knocking out the modem. Like TVI knocking out analog TV.
Have you tried relocating the rig or the modem to another location? Is the rig located near the modem? I can't explain the day you used 1K and the modem working, but I got to suspect RFI knocking out the modem and really, you may have to isolate by relocating one of them, at least to troubleshoot the issue. |
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ke3nj
join:2007-12-27
Danville, PA | reply to tschmidt
Hi,
What I meant was that most of the time 10 watts will shut me down. But on 2 occasions I could run 1000 watts and the system worked great. That is the puzzling part. |
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ke3nj
join:2007-12-27
Danville, PA
| reply to Slidetbone
Hi,
Tomorrow I'm going to relocate the modem to the phone jack that is the greatest distance from the shack. I've tried 3 different modems and all behaved the same way. Keying my transmitter shuts me down. I'v also tried 3 different transmitters, by 3 different manufactures, all produced the same results.
KE3NJ |
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dei2
join:2007-02-07
Willingboro, NJ
| have you looked in to building your own RF / EMI Shield around the modem case ? I had to do with with the motor in my tread mill. The TV in the same room would have a snow effect on it. Trying to listen to Am radio in the house was also imposable. Now that i Have the motor shielded things are fine.. Maybe if you shield the modem things may work better... But if the RF is being picked up by the phone lines in the house, you may not be about to stop it. |
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ke3nj
join:2007-12-27
Danville, PA
| Hi, Concerning building an RF shield around the modem/router. I'm beginning to believe that might be the only answer to my problems. Moving the antenna further away from the modem & Phone line was no help. I've started looking for a metal container that would house the modem. I all ready have the feed throughs for the DC power to the Modem. I'm hoping that I will be able to find some shielded phone jacks. I have a shielded ethernet cable but still need the female receptacles for both. I'm also looking at building a framework out of aluminum angle stock and then covering it with the perforated aluminum sheets. The best material would be copper but if I am able to find copper materials (angle stock, etc.) it probably will be cost prohibited.
Dave |
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tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
·Hollis Hosting
·Verizon Online DSL
·Fairpoint Communic..
| said by ke3nj  : I'm hoping that I will be able to find some shielded phone jacks. I have a shielded ethernet cable but still need the female receptacles for both. Before you go to all the effort and expense at building a shielded enclosure. Might want to try slapping ferrite on phone line and power cord.
/tom |
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Catch22007
join:2004-02-19
Danville, PA | reply to ke3nj
I would bet money that the problem is EMI over the power lines. Try using a filter on your power instead of the phone lines.
My Treadmill does the same thing. |
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Catch22007
join:2004-02-19
Danville, PA | reply to ke3nj
hah I just saw you were in Danville as well, cool! |
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ke3nj
join:2007-12-27
Danville, PA
| reply to tschmidt
I've tried some ferrite on the power leads (from the wall wart and the ethernet cable from the computer to the modem. I used some Radio shack ferrites and the ferrite rod out of a B & W FC 25 filament choke. Didn't see any change. I'm not sure that the radio shack ferrites are good at 160 meters. So I'm looking for some ferrites that I know for sure are good for 160 mtrs. I tried another phone jack this morning, it was better I could tx at 50 watts without the modem dropping the internet. I thought that distance between the modem and transmitter might be the answer. So I ran a new phone jack using twisted shielded pair wire. That turned out to be just as bad as the original, even though it was about 15 feet further away from the transmitter.
I've tried K-Comm filters .5-3mhz and 3-30mhz,both alone (one at a time) and together. I have 2 each of the filters, tried all sorts of combinations, right before the modem and where the telephone line enters the house. No improvement. I have 1 Excelsus RF Interference Filter Model L-222RJP(www.excelsus-tech.com), Tried that also with no improvement, both at the modem and where the phone cable enters the house.
The fact that it has worked fine with up to 1000 watts for as long as about 14-15 hrs in a row and one time for 2 hrs and the rest of the time 10 watts will cause the modem to drop the internet. Leads me to think there is some kind of intermittent problem, possibly in the antenna/feedline,ground or the phone line. The modem has dropped the internet a few times without the transmitter being on. That even happened when the Verizon DSL tech was here. Tomorrow if the weather holds, I hope to check all the connections to ground to insure good clean connections.
I'm not ready to give up yet.
KE3NJ Dave |
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Catch22007
join:2004-02-19
Danville, PA | You can also try wrapping foil around the modem. |
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ke3nj
join:2007-12-27
Danville, PA
| reply to Catch22007
Hi tschmidt,
Wonder where you live in Danville, Pa.? My name is Dave Letterman, I live between Danville and Milton on Narehood Road. Are you a Ham?
Don't know where I can buy good ferrites locally do you?
I did try a 7" ferrite core from a B&W FC-25 filament choke that is supposed to be good for 160 meter frequencies. I used that on the DC power lead coming from the Wall Wart to the Modem. The Transmitters are all powered by a DC (13.8 volt) power supply. I have 2 different power supplys,1 is a switching supply and the other is an analog supply. Didn't' see any change in operation. If I could find some GOOD LOW FREQUENCY Ferrite's, I could try them on the AC power leads to the power supplies. Again the intermittent, occasionally (working at full power without interference) is difficult to understand.
KE3NJ Dave |
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ke3nj
join:2007-12-27
Danville, PA
| reply to Catch22007
Hi,
All ready tried the foil around the modem, double wrapped it, tried it with and without an earth ground. No change.
I'm including a url that will take you to the spec sheet of the Exculsus filter that I'm using on the phone line:
»www.excelsus-tech.com/Downloads/···RJDP.pdf
The specs look good but paper will stand still for anything.
KE3NJ Dave |
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Catch22007
join:2004-02-19
Danville, PA
| reply to ke3nj
No idea where to get anything around here, I have been looking for a good filter for the Treadmill. I put an old one on that was laying around and it helped but did not cure it 100%.
I live out on Toby Run, not into HAM. Funny story though, just the other day I was looking through the phone book and saw your name Dave Letterman in Danville and thought...' I should call this guy and ask for tickets to his show! '
=) |
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mb
join:2000-07-23
Washington, NJ
 ·Comcast
 ·Callcentric
·Vonage
·Verizon Online DSL
1 edit | reply to ke3nj
Can you hear any interference on a connected telephone when transmitting? My guess is that your telephone wiring is acting as an antenna and simply overloading the modem's transceiver. 1KW is a lot of RF. If so, the first step would be to isolate on which side of the NID the problem lies. I found a NID mounted K-Comm filter to be helpfull when I was getting into my neighbor's telephones with 100 watts, but the interference wasn't totally eliminated.
--
"When will they ever learn? When will they ever learn?"
Pete Seeger 1961
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ke3nj
join:2007-12-27
Danville, PA
| reply to Catch22007
Hi, I know where Toby Run is, I know Carl and Carol Wright that live on Toby Run.
Unfortunately, I'm not related to the Dave on TV! I'm older though (65). I have 2 cousins with the name plus there is a 4th Dave Letterman that has a resturaunt in the Bellefonte area. He isn't related either.
KE3NJ Dave |
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ke3nj
join:2007-12-27
Danville, PA
| reply to mb
Hello,
No, we can't hear the RF on the telephone line either before or after the DSL installation.
You see that is the puzzling part, most of the time as little as 10 watts will cause the problem. On a couple of occasions (one for 14+ hours) I was able to use 1000 watts with no problem. I've used the K-Comm filters (singularly and together, both at the NID and at the modem. Even tired it with the modem double wrapped in aluminum foil, with the foil both grounded and ungrounded. With no improvement.
KE3NJ Dave |
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Rattler
join:2001-04-13
Havertown, PA
·Verizon Online DSL
 ·Verizon FIOS
2 edits | reply to ke3nj
Not that this would possibly fix your problem but... In my younger years I was a HAM and did a lot of CW on 80M. I only ran 120 Watts and, invariably when I keyed the xmitter, the upstairs hall light would let everyone know that I was on the air (whether the light was switched on or off).
I suspect that if you have an aerial telephone wire, running from a pole to your house, that it is acting like a receiving antenna on 160M. It probably doesn't take much power, impressed on the phone line, in the 160M band, to de-sync the connection between the modem and CO.
Do you notice whether the interference is specific to any particular frequency you use or is it universal across the band?
--
Never raise your hands to your kids. It leaves your groin unprotected. -- Red Buttons |
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guppy_fish
Premium
join:2003-12-09
Lakeland, FL
·Verizon FIOS
1 edit | reply to ke3nj
Start with the basics,
at the NID, disconnect the home wiring and connect the modem right at the NID ... that will tell you if its the plant/street or inside wiring that's your issue
Also, are the 10w / 1kw amps different?, possible distortion issues or leakage? what about your antenna wiring, the home wiring and grounds? Any visable interfernace with TV? |
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