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Interference from Verizon Fios on Ham Radio equipment.

Posts: 1
Registered: ‎07-22-2013

Interference from Verizon Fios on Ham Radio equipment.

Message 1 of 6

              Hello all recently got Verizon Fios installed and now i'm getting terrible hash and noise from it,HF is horrible 75m 80m 160m 28m etc, was on the phone with them (verizon phone tech) and was like talking to myself no knowledge whatsoever. The day Verizon tech hooked up everything as should be a unit outside the house, a backup unit (ups) inside the house just under the window inside and 5 feet away from the outside unit, when I run cat 5 from the modem/router to my comp i get tremendous hash when I remove the cat 5 the noise is totally gone I do not have phone service just internet and TV... I did some extensive testing changing cat 5 cables ferite chokes 31mix 43mix to no avail!! BUT here is the real kicker when i disconnect power from the Actiontec MI424WR router/modem (just cat 5 from router/modem to computer) and put the coax center pin in the modem first all still quiet on my Ham Radio RX, but when the ground is screwed on my RX is a nightmare??? This blew me away because there is no power being applied to the router so how and what is being transfered to cause the interference grounding?. I checked the outside ground for the unit outside and it is fine...This sounds like a ground issue with the outside unit? I don't know, naturally if i turn off the computer i get no interference at all...all i can say is bizarre! Had Verizon tech come out to the house changed all compression fittings replaced 2 splitters, tested another Router replace cat 5 from modem to comp....NADDA same prob..sounds like 60hz type buzz...doing some research the battery back up (UPS) has an internal charger,charging the back up batt could be the batt charger leaking RF in the house and grounds? ...Has anyone had this problem the tech is stumped and has no idea..

Moderator Emeritus Moderator Emeritus
Moderator Emeritus
Posts: 6,227
Registered: ‎04-29-2009

Re: Interference from Verizon Fios on Ham Radio equipment.

Message 2 of 6

Your issue has been escalated to a Verizon agent. Before the agent can begin assisting you, they will need to collect further information from you.Please go to your profile page for the forum, and look in the middle, right at the top where you will find an area titled "My Support Cases". You can reach your profile page by clicking on your name beside your post, or at the top left of this page underneath the title of the board.
Under “My Support Cases” you will find a link to the private board where you and the agent may exchange information. This should be checked on a frequent basis as the agent may be waiting for information from you before they can proceed with any actions. Please keep all correspondence regarding your issue in the private support portal.

Employee Employee
Posts: 3,229
Registered: ‎04-10-2013

Re: Interference from Verizon Fios on Ham Radio equipment.

Message 3 of 6



I am glad that  we were able to get this issue resolved for you! If you ever need anything from us, we are here for you around the clock.

Copper Contributor
Copper Contributor
Posts: 6
Registered: ‎08-14-2013

Re: Interference from Verizon Fios on Ham Radio equipment.

Message 4 of 6

Contact ARRL league Headquarters - RFI services if Verizon does not resolve the issue for you.


They are tracking Part 15 leakage emiissions of Cable & Internet providers that have been fined by the FCC

for non-compliance in sloppy RFI equipment and installations.


More info for the Verizon Service Techs to read and clues for you.


Copper Contributor
Copper Contributor
Posts: 6
Registered: ‎08-14-2013

Re: Interference from Verizon Fios on Ham Radio equipment.

Message 5 of 6

What you are seeing is the Switching Power Supply cycle on and off, 15 seconds on, 45 seconds off,

constantly to keep the back up battery charged. Also the Switching Supply has close to 10KHz pulses 

that generate a Square Wave rich in harmonics that generate Harmonics. The filtering from 14MHz to

430MHz is almost non existent.


Maybe with luck, you might get 20dB more rejection with shielding, but that may not be enough !


Verizon's System Engineering for FIOS, if it even exists, would need to look at this to really solve the problem.

Most places just buy Third Party componets abd deploy this crap out in the field. 99.5 % of the time, it works, but in your case your the 0.5% and not in their norm for them to know what is going on !


( FFT) Fast Fourier analysis of a square wave that represents their signal content to be very broadband

from their unit. Having a receiver that can see almost down to -120dBm makes it very difficult to eliminate 

such interference. 


Verizon would need change the way they are charging the Back up Battery without a Switching Supply. 

The typical Verizon Techs are just hands on Monkey Techs with no real knowledge. You need to talk to a real 

RFI Engineer to really know how to solve the problem. '


Good Luck, very few at Verizon know what's going on, unless you talk to a real Engineer.



RFI Engineer


Copper Contributor
Copper Contributor
Posts: 6
Registered: ‎08-14-2013

Re: Interference from Verizon Fios on Ham Radio equipment.

Message 6 of 6

Another thing is that a Common Ground actually may cause more RFI issues.


Look into Coaxial Line Isolators, they are essentially Ferrite Sleving to go outside 

coaxial lines. To get 60 dB attenuation, clamp on types are useless at your HF frequency.

14MHz to 144MHz 


Look at those from for your station.


Also,Verizon Technical Services and Engineering could use 75 ohm types on their system to keep RFI radiating off the Gound Shields of their Coaxial Lines, The Ferrite would need to be massive, non-clip on types to

get RF out outer shield of their FIOS cables into your residence ( Ham Station ). could make smaller 75 versions for Verizon easily !!


Wondering if any Technical Engineers at Verizon even read these forums !


Good Luck, seem like we have to educate Verizon !



RFI Engineer


{short description of image}


The Ground Loop Solution

The RFI Quick Fix™

Line Isolator Circuit



50 ohm, 5.8° delay, 160 - 10 m, >1500 W*, SSB/CW, >80 K isolation.

T-4 Plus

All of the features of the T-4 with increased bandwidth covering 160 - 6 meters.
T-4G & T-4G Plus

The ULTIMATE - grounded version of T-4.
VHF Line Isolators
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Finally, a Line Isolator for 10, 6, and 2 meters! Check it out.

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Physically, only 1/4 the size of the T-4 Line Isolator, but but even better performance. It will handle up to 500 watts on SSB/CW.
* CW/SSB duty-cycles only. Not rated for AM, RTTY, or other high duty-cycle modes.


The Ground Loop Solution


Multiple ground loops around various pieces of equipment can cause all sorts of problems. But, rather than getting deeper into a technical discussion, let's just try to avoid problems before they cause trouble. Solving the ground loop problem may be as simple as adding 'LINE ISOLATOR™ in series with the interconnecting coaxial cables between station equipment.


First, eliminate the heavy copper strap running along the back of the station equipment. Use the antenna tuner as a common ground point, 'Ground Central.' The heavy gauge wire, strap, or braid from your outdoor ground system will connect directly to the 'common ground point' on the back of the antenna tuner. Each piece of equipment will then be connected directly to this 'common ground point'. Actually, each piece of equipment is already connected, in a round about way, to the antenna tuner through the various pieces of coax that interconnect station equipment. Of course, it is this "round about way" that contributes to the ground loop problems. We can't eliminate the ground braid on the coax, but we can break up the external ground loops with LINE ISOLATOR.


Line Isolator


The Line Isolator setup shown above works well for most stations. Customers report that LINE ISOLATORS™ inserted in series with the cables interconnecting the transceiver, linear and antenna tuner have eliminated stubborn RFI problems that resisted being solved by other means.


How it works


Placing a LINE ISOLATOR at the output of the transceiver or linear amplifier, prevents RF from traveling along the outer surface of the coax's shield. Any RF current flowing on the coax braid that can be radiated or coupled to other equipment is forced to ground by the very high impedance of the LINE ISOLATOR. RF current always takes the path of least resistance. Of course, the LINE ISOLATOR does not affect the signal inside the coaxial cable. The LINE ISOLATOR installed in series with the transceiver and linear amplifier helps the transceiver's output filters perform more effectively by breaking a secondary (leakage) path.


The T-4G


The T-4G is installed at ground level within a few inches of your ground system. It's built-in ground strap provides a direct path to ground for any stray on the coax, while the very high impedance of the Line Isolator's windings prevent from traveling up the coax an into the radio room. It's a very effective solution.

The T-5G
The T-5G takes the process one step further. VHF isolation is added and a second ground strap is included for more effective bidirectional operation.

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