Pages: [1] 2   Go Down

Author Topic: 40m crashes my internet.  (Read 347 times)

5BWAZ

  • Member
  • Posts: 97
40m crashes my internet.
« on: June 11, 2022, 11:33:52 PM »

Hello,

Recently when I transmit on 40m with high power it takes down my internet. This only started happening in the past month or so. I have ferrite on all the cables going into and out of the cable modem and router. I'm also using DX Engineering ISO-Plus Ethernet RF Filters on each end of the cable connecting my shack computer to the router. I don't really know what to try next. Any ideas? Thank you
Logged

G4AON

  • Member
  • Posts: 2178
Re: 40m crashes my internet.
« Reply #1 on: June 12, 2022, 01:16:49 AM »

I used to have problems with dropped internet when transmitting on the lower bands. Filtering wasn’t effective, I went wireless internet (WiFi) in the shack and haven’t had a problem since.

73 Dave
Logged

G8FXC

  • Member
  • Posts: 533
Re: 40m crashes my internet.
« Reply #2 on: June 12, 2022, 08:24:18 AM »

I can get away with 40m provided I don't try to go above 100W, but 80m is very disruptive. Filtering and decoupling will help, but there is no magic wand. I think the problem is quite simply that modern internet signalling runs at frequencies between around 3MHz and 12MHz. It causes at least as much interference to us as we do to the internet...

Martin (G8FXC)
Logged

KH6AQ

  • Member
  • Posts: 9292
Re: 40m crashes my internet.
« Reply #3 on: June 15, 2022, 06:13:37 PM »

Have you confirmed that it is the cable modem and router by observing its status LEDs?

What has changed since 40m high power did not crash it?
Logged

WA3SKN

  • Member
  • Posts: 8126
Re: 40m crashes my internet.
« Reply #4 on: June 16, 2022, 03:36:43 PM »

Sounds like you have a "fundamental overload" problem. Too much RF in the area overloading something.
I would start with wrapping the internet cable and router in aluminum foil and grounding it with an alligator clip wire to start, since you already have some ferrites in place.  How close is the transmit antenna to the cable eqpt? Shielding any CAT5 cables can help too.  Check the hardware store for aluminum tape.  It has many shielding uses.  With all interference issues, it is "distance from the transmitting antenna", "shielding", and "filtering" are the answers!
Now are you a "wired" or "wireless" connection?

-Mike.
Logged

5BWAZ

  • Member
  • Posts: 97
Re: 40m crashes my internet.
« Reply #5 on: June 20, 2022, 09:37:31 AM »

Thanks for the replies, guys. I've done some testing the past few days, and it looks like the only direction that takes out my internet is NE, which is right in line with my modem and router. The modem/router sits about 45' from the tower in the other room. Unfortunately, because of where the internet enters the house, it's not practical to move it. Thinking out of the box here, is there any way to shield the modem and router with some kind of contraption or cover to keep the RF out? Any other suggestions? I don't think wireless is an option since it completely kills the internet.
Logged

G8FXC

  • Member
  • Posts: 533
Re: 40m crashes my internet.
« Reply #6 on: June 20, 2022, 09:41:47 AM »

Thanks for the replies, guys. I've done some testing the past few days, and it looks like the only direction that takes out my internet is NE, which is right in line with my modem and router. The modem/router sits about 45' from the tower in the other room. Unfortunately, because of where the internet enters the house, it's not practical to move it. Thinking out of the box here, is there any way to shield the modem and router with some kind of contraption or cover to keep the RF out? Any other suggestions? I don't think wireless is an option since it completely kills the internet.

Do a web search for "DIY faraday cage" - you'll find plenty of advice.

Martin (G8FXC)
Logged

KH6AQ

  • Member
  • Posts: 9292
Re: 40m crashes my internet.
« Reply #7 on: June 21, 2022, 06:15:22 AM »

The next step may be to try a different brand/model of modem/router.
Logged

WA3SKN

  • Member
  • Posts: 8126
Re: 40m crashes my internet.
« Reply #8 on: June 21, 2022, 03:58:00 PM »

Cardboard box and aluminum foil, or just use metal screening and an alligator clip to ground.  There are lots of ways but do plan on air flow and cooling.

-Mike.
Logged

KO7I

  • Member
  • Posts: 144
Re: 40m crashes my internet.
« Reply #9 on: July 06, 2022, 02:16:31 PM »

When I got an Acom 2000a I immediately had to deal with Comcast cable modem crashes when running above 400w out.
I have a remote antenna switch and only one length of RG213 coax coming back to my station.
I added a common mode RF Choke to the RG213 coax cable.
I also added multiple clamp-on 43 mix fairrite beads to the coax feeding the cable modem.
In addition to that I add a couple clamp on 43 mix fairrite beads, both with multiple turns of power lead feeding the cable modem.
I can now run legal limit power without disruption of internet service.
Also, I had to relocate the cable modem elsewhere in my house away from my ham shack.
To be honest, I need to add a dedicated earth ground rod for my exterior antennas. My bad.
Logged

AI5BC

  • Posts: 456
    • HomeURL
Re: 40m crashes my internet.
« Reply #10 on: July 07, 2022, 11:46:00 AM »

Try this test. Get yourself an AC cheater plug and plug your DC power supply into it. If your problem goes away report back. Do not connect anything to the green tab, leave it open.

Logged

NA4M

  • Member
  • Posts: 212
Re: 40m crashes my internet.
« Reply #11 on: July 10, 2022, 07:25:37 PM »

I've had problems previously with RF crashing our cable modems. 

Wrapping the modem's DC power cable as many turns as possible around a large mix #31 toroid as close to the modem as possible worked wonders.
Logged

5BWAZ

  • Member
  • Posts: 97
Re: 40m crashes my internet.
« Reply #12 on: July 31, 2022, 02:58:08 PM »

Today I put a lot of attention on the AC power leads into the Spectrum router and modem (they're separate devices), with particular focus on the modem since the RF takes down the internet completely.
I used one mix 31 1.4" DI ring with 8-9 turns on the modem, and a couple of 1/2" snap-on's with 4 turns each on the router, and it worked. I'm cautiously excited that I finally solved this issue, and here's where I ask a stupid question since I'm learning and really don't know.

Now cured, is this usually a permanent fix? I'm afraid to touch anything around the modem/router that might start this RF issue all over again.

Thank you all for your input. I learned a lot.
Logged

W9IQ

  • Member
  • Posts: 8866
Re: 40m crashes my internet.
« Reply #13 on: July 31, 2022, 03:12:52 PM »

Congrats!

Unless something changes, it should be stable. If any more problems crop up, another type 31 toroid or two should bring it back in line.

- Glenn W9IQ
Logged
- Glenn W9IQ

God runs electromagnetics on Monday, Wednesday and Friday by the wave theory and the devil runs it on Tuesday, Thursday and Saturday by the Quantum theory.

K0UA

  • Member
  • Posts: 9589
Re: 40m crashes my internet.
« Reply #14 on: August 01, 2022, 05:47:18 AM »

Today I put a lot of attention on the AC power leads into the Spectrum router and modem (they're separate devices), with particular focus on the modem since the RF takes down the internet completely.
I used one mix 31 1.4" DI ring with 8-9 turns on the modem, and a couple of 1/2" snap-on's with 4 turns each on the router, and it worked. I'm cautiously excited that I finally solved this issue, and here's where I ask a stupid question since I'm learning and really don't know.

Now cured, is this usually a permanent fix? I'm afraid to touch anything around the modem/router that might start this RF issue all over again.

Thank you all for your input. I learned a lot.

You should be "good to go", but if you are on "the ragged edge" of just barely fixed, then do more of what you did before. I ran into that when I went up on power level with a new amp. I had to add some more suppression on a couple of things. No big deal as I already knew what to do from solving the problem at the lower power level.

Isn't it great to be faced with a problem, but you applied scientific principles and it paid off with a solution? You should feel proud, and you added to your knowledge base. After all, that is what an amateur radio license actually is, a license to learn. And you have started down the learning road. Bravo, and congratulations.
Logged
73  James K0UA
Pages: [1] 2   Go Up