RF buzzing my house wiring

[Gus Chiggins]

Hi,
Been messing with this for a while now so was hoping someone else has seen this and might give me some suggestions.

Symptom: AM modulating near 500W peak causes bedroom house power wiring to buzz along with the modulation. This only happens in the room directly below the antenna. Unfortunately, that room is the master bedroom which means I can't crank it up after the XYL goes to bed. Loud enough to keep her awake. Mamma not happy. No late night radio for me so I'm not happy either.

Setup: RCI 2950 and new Texas Star DX500 feeding new Super Penetrator on gable mount with short mast and radials sitting about 10' over roof ridge gable end. LMR-400 runs down mast then along roof line facia board to corner of house then down to basement. Coax goes under house then 60' to shack. Coax connects to a 30Mhz low pass filter then swr/watt meter then DX500 then radio. Match on meter shows 1.2:1 with amp on and 1:1 with amp off. Power supplies are 2-Megawatt S-700-12 in paralell at 14.2VDC @ 100W. These power supplies are highly filtered and regulated. The 2950 carrier is set to 2 watts and peaks to ~20 watts with modulation. Based on many radio checks (subjective) my audio is very loud and clean. The DX500 dead keys to 125 watts and peaks to ~500 with modulation. Mode of operation is AM.

What I've tried: Moved coax under house around to get away from any visible 110VAC wires. Grounded antenna to 6' copper rod and then moved ground a copper water pipe hose bib. Tried grounding all shack gear chassis to cold water ground. Tried a 10awg tie line between ground points in shack and under antenna. Added the low pass filter. Tried un-grounding everything. Grounding and coax positioning and low pass filter seem to make no difference. Tried different mobile radios with no change. DX500 on low setting does not cause this issue. Only at about 500W Peak on AM does this happen.

Was thinking of raising the antenna up higher on a 3-piece telescoping mast. Need to get some more LMR400 first. Going to do this anyway and maybe the added antenna elevation will allow me to run lower power.

Any ideas/suggestions would be appreciated.
I live very rural in the mountains and can barely reach stations in town even with the DX500.
Thanks,
Gus

[Gus Chiggins]

sorry meant 14.2VDC @ 100Amps.

[51]

it could be a handfull of things, 1st off rf is getting into your wiring. it could be common mode currents (not likely), poor ground system (most likely), high rf power to close to the house and the wiring is long enough to be a resonant receiving antenna(possible) or a combination of all three. i almost guarantee your ground system is the cause. one ground rod with a wire attached does nothing, not even for lightning. more info?

[51]

ok i just looked at pictures of a gable mount, now im 99% positive your rf ground system is the cause. if you want info on a proper rf and dc ground system, post back. i can guide you thru it. when your done you WILL get out and you WONT rattle the house with tx rf.

[Gus Chiggins]

if you want info on a proper rf and dc ground system, post back.

I do want info. 99% is pretty dang strong.
I have to fix this.
I suspected ground right away but could not see any changes when I messed with the grounding. I didn't eliminate grounding but just started looking at other things like coax path and antenna radiating element proximity to house wiring.

Available existing ground points are
1. Copper cold water pipe entering the earth about 15' east of antenna mast location.
2. Copper cold water pipe entering the earth about 15' from radio room.
3. Crappy grounding at breaker box from power company not hear either antenna nor shack.

---

BTW I'm changing to a more solid type of wall mount as soon as my LMR400 comes in and raising the antenna at least another 20' high.
The wall mount will be much more stable but will be in the exact same position for the mast. I'll expect the same grounding issues.
Thanks for the help.

Antenna Parts Outlet Model EZ 30-30W is the type. I tried to post an image or a link to an image but would not let me.

BTW I have VERY few exterior antenna options due to strict HOA restrictions. And by HOA I mean my wife. :D She is a hard **Censored** on aesthetics and for some reason she can't see the beauty in a tower.

Gus

[Gus Chiggins]

Looking at winding a choke with my coax at the amp end maybe on the patch cable between the meter and the low pass filter.
That LMR-400 is STIFF!

[jon6667]

move the antenna

[Gus Chiggins]

I can raise the antenna but cannot "move" it. See previous comment about HOA

[51]

ok this is gonna be kinda long, so here we go. first, to clarify the two ground systems you need. 1. RF GROUND system: to keep rf in the air where it belongs, help with ground conductivity,lower radiation angle, lower your receivers noise floor and reduce stray rf just to name a few. 2. DC GROUND system: to eliminate static charge build up, help reduce the the chances of a lightning strike, minimize symptoms of a nearby lightning strike etc. ok now for the dc ground system first. as a general rule of thumb nothing can prevent a direct lightning hit, it is something you can just try to minimize the chances of and hope for the best. if you take a direct hit it will destroy your station equipment at the least and at worst kill someone, burn down the house etc. commercial stations can stay on the air after a direct hit only because they spend thousands of dollars on multi stage lightning arrestors and ground systems, and the arrestors only last once. you get hit you gotta replace them. so the bad news is, that type of protection is way beyond our financial means. the good news, a properly designed and installed rf ground system will double as a decent and primarily effective dc ground system as well, which is something we can afford . now before we move onto the rf ground i will explain why a wire to a ground rod does nothing really and can actually cause more problems with rf. (disclaimer: any ground is better than no ground at all as far as dc goes) lightning follows the path of least resistance, so when a hit occurs, it will see a long thin copper wire with a high resistance and some capacitance to ground, or a nice big fat low impedance coax with several conductors in it that is a straight shot, which would you choose? if you said the coax you would be correct. in most cases a lightning bolt will vaporize that thin copper wire like a fuse cutting off the path to ground thus forcing that strike down your transmission line. ( remember the very expensive arrestors i spoke of?) and as far as rf goes, that long thin copper wire will act as an antenna when you transmit and will re radiate your rf as harmonics, distort your radiation pattern and cause problems. alright are you still with me ? cool, lets move on to the ground system you need to build. ok a phenomena you need to know about before we build our ground system ( i know, we are almost there. trust me). rf and lightning like to follow a thing that is called the "skin effect". it likes to travel on the outside of wide, flat, low resistance conductors, not thru the center like you would think. this is the major reason why using high impedance narrow, round wire is not a good idea. not enough low resistance surface area for the energy to travel.( note: you can use very large 1/0 or bigger copper cable for dc ground but this must be done usually in addition to a well designed system. ok, now that you know that energy likes to travel on the outside of conductors ("skin effect") we will no longer be using copper wire as a bonding source, we will be using tinned, braided copper ground strap. ( 3/4 inch wide minimum). alright now that you know some basic theory, lets build your ground for your setup ( told ya we'd get here eventually). first, you need to get rid of that short pipe mounted to the corner of your roof eve. you need to install a full length mast or tower section that starts at about 2ft in the ground minimum and extends as high as you want it. in other words, if you have a 20ft pole, your gonna bury at least 2ft of that pole so now your antenna mast will be earth grounded at the base as well as supported. now install whatever other method of mounting you need to secure the mast. (guy wires, wall clamps etc) if you use guy wires we have rules for that too, i know i know lol. now we install the ground radials. (this is the only time we will use copper wire and get away with it because it will be a reflector). at the base of your antenna mast, as close to earth as possible, connect 1/4 wave length radial wires,14g minimum. clean the mast connection point of any coating etc using sand paper, wire wheel or whatever you have. the preferred method to mount the wires is on a bolt thru the pipe with eyelets, but you can just hose clamp the bare copper wire to the pole if you have to. make sure to use conductive grease in the connection to increase conductivity and reduce the galvanic reaction (corrosion) due to dissimilar metals. now water proof this connection. to the pole mount as many ground wires as you can. if you can only fit 4, use 4. if you can fit 30, use 30, or anything in between etc. you get the point. spread the ground wires straight out evenly like the spokes of a wheel (as much as possible), if they cant be perfectly straight at the end its ok but straight is the goal .now next to the length each ground wire make a slit in the earth 3-4 inches deep with a shovel, a hoe or some tool like that. now put the wire in each of its trenches and cover back up with earth. next connect a 4in piece of ground strap to a 6 ft minimum ground rod and drive the whole length into the ground. only an inch or so should be sticking out when done. as a side note, if you can get a short ground cable run and i mean short (under 1/4 wave long) to the house earth ground connection point connect your new antenna ground rod here as well. your antenna dc ground will be tied into the house earth ground , if you cant, you cant. ok now you can mount your antenna to your new mast. finally, at your antenna feedpoint, make a coil out of your coax, 6 turns at 6-8 inches in diameter tape it up. it doesnt have to be perfectly uniform, just a basic coil. now connect this coil end of your coax to the antenna and secure the coil to the mast. this coil is an rf choke and will help reduce or eliminate common mode current and feedline radiation. alright bud we are done, outside anyway. this will help immensely with lightning and static dispersion and it will also act as your ground plane thus lowering the radiation of angle of your antenna.you will be VERY surprised and happy with your new antenna system. next you need to set up a good station ground system, but we can do that another day. do all of this and the dx contacts will blow your mind! ps now you have a safe as you can get within budget antenna system that will sound great, and if you still have rf problems, even with a station ground installed as well (highly doubtful) we will need to look at equipment faults.( cranked open radio pots, peak and tweaked radio garbage etc........ have fun

[Gus Chiggins]

Awesome reply 51. Thanks for the help. I mean that.
I've got a few issues with the design. Not that I don't think its right. I do.
Execution is going to be a problem. My HOA fines for violations are harsh. IN CASE you missed it. My "HOA" is my wife who is trying to fix up the outside of our mountain home with her designing eye. She is good at it but my Antenna don't fit her chosen design inspiration which is something called "rustic modern"??? Apparently rustic modern does not include towers and aluminum.
The mast is pretty much going to have to stay where it is. I can get away with some wall mounts to strengthen it up for a telescoping mast and I can run guy wires. Already getting guff about the one guy that will have to be ran to the tree in her back hard.
There is a deck right below the gable and I don't see the XYL letting me drill a hole in it to bury the mast. Even if I could sell that one. The house foundation would be in the way of 1/2 of the ground legs and the entire ground circle would be canted at almost 40 degrees. House is built on a pretty steep hill.
What you say make good sense. I know at higher power levels these things become more revealing. I guess 500 watts is about the threshold for my setup.I also get what you are saying about cleaning up my receive.
I think what might be making things worse for me is the very high iron content in the soil here.

Here's a question. Are there any antenna designs that might minimize this issue? Would a beam help? I have my old rotor setup I could put up there. I can run that heavy braid along the roofline and down the corner of the building and tie it to whatever makes sense. But I don't see building a ground grid under the antenna in the dirt.

I don't have a problem spending money to improve my situation.

[51]

hmm, in that case you are limited in what can be done somewhat. to work with what you have first, i would get a mast, mount the base to the deck for support, get that ground plane antenna as high above the roof as you can, at least 1/2 wavelength, this should eliminate a possible proximity effect to the house wiring and will also lower your radiation angle. make the rf choke like i described to tame any common mode current on the shield of the transmission line. somehow figure out a way to get an earth ground on that mast. check the results on air. (running a vertical can be hard to tame sometimes because your rf is everywhere) if you can run a beam, that will help with rf control immensely. if your gonna run guy wires make sure you break them up with insulators every say, 7ft or so. you dont want your guy wires a quarter wave in length or more, they will re radiate your signal as rfi and harmonics. set up a good station ground to compensate somewhat. and finally, remember if you are running cranked open limiter clipped etc gear, you WILL tx harmonically rich splatter and your amplifier will enhance the effect. no amount of anything will help that. run the station clean, 100% audio (no more) and keep your final output on AM to the 4:1 ratio and you will have a quality sounding broadcast station

[MDYoungblood]

This topic is very interesting to me since I have never ran across this problem. The electrical wiring making noise?, normally it is the other way around. I could see it being possible with the use of romex cable and all those plastic junction boxes. I would like to see a YouTube of this effect , mainly where the noise is the loudest.

What 51 is saying sounds great and I could add a couple things.

First thing I would do is check out every electrical connection in the house, particularly that master bedroom, somewhere is a loose connection, wire nut needs tightening, a receptacle screw loose, and while looking make sure someone hasn't crossed wire types, aluminum and copper don't mix and can actually cause noise (and a possible fire later) in the system.
Separate the antenna system grounding/bonding from the electrical ground, don't have them both on the same ground rod outside, add another rod, they can be close but I'd keep them as far apart as possible.
You can try the chokes (air choke, dirty chokes, etc.), I would make 2, place one between the radio and amp, the other just outside before the coax enters the house. You could use ferrite beads (snap on type) too, type 31 or 43, at least 6 together per coax, I have mine right under the antenna's connection and the choke at ground level.
If the coax is old it might need to be replaced, I go good quality there, while doing this take the antenna down and clean it up checking all the measurements, an out of tune antenna will cause interference.
Last is just my opinion. I never run an amplifier and radio together on the same power supply even if it would handle it, my reason is when the amp draws power it lowers the voltage also to the radio detuning both. That said I was never a fan of using a mobile amplifier for base use, mobile amps are fine for a vehicle where good filtering is not necessary but you are experiencing my reasoning there. The cost of a quality amateur amplifier with the proper filtering and built in power supply is well worth the money for base use, like I said it's my opinion.

3's

Greg

[jessejamesdallas]

Just wondering if it's actually the wiring making the noise...or a breaker switch in the breaker box...If a breaker is loose, high RF could make it sing...or in this case..."Talk"...

...right before it shorts out and catches fire...

[Gus Chiggins]

Ok some history with my comments in yellow

"The electrical wiring making noise" - yeah its friggin weird. I thought it was a bad outlet at first. Seemed to be coming from one outlet. Replaced it and nothing changed
"mainly where the noise is the loudest." - Well when I really get on the mic, it sound like it's coming from 3 walls. Two exterior and one interior all have outlets. Really hard to pinpoint a single location.
"check out every electrical connection in the house, particularly that master bedroom, somewhere is a loose connection, wire nut needs tightening, a receptacle screw loose" GOOD ADVICE! Need to crawl around in the attack and see if there are any junction boxes that need attention and pull all the outlets and switches and check them.
"make sure someone hasn't crossed wire types" you mean you mean like swap common and hot? I used one of those 3 light testers on every outlet. Seems ok
"aluminum and copper" All copper thank God
"Separate the antenna system grounding/bonding from the electrical ground - I assume you mean the house electrical ground. Did that. Tried every combination I could think of with absolutely no change in condition.
"don't have them both on the same ground rod outside, add another rod, they can be close but I'd keep them as far apart as possible" Shack is 60' from antenna at the other end of the house.
"amplifier and radio together on the same power supply" Ok I'll separate them and see what that does.
"quality amateur amplifier " Been thinking about that too. This Texas Star is about as bare bones as you can get. No protection or filtering of any kind.

I'm starting to think I'm splattering due to over-modulation. Crap goes in - crap comes out X 100. I'll have an o-scope in about a week so I can check if I'm flat topping or pinching the carrier. Making a tap now.

Just wondering if it's actually the wiring making the noise...or a breaker switch in the breaker box...If a breaker is loose, high RF could make it sing...or in this case..."Talk"...

...right before it shorts out and catches fire...

Well the breaker box is on the opposite corner of the building.
Pardon my ignorance but...
What does "breaker is loose" mean exactly?
And…
Are you joking about the fire?

Thanks everyone

[Gus Chiggins]

(running a vertical can be hard to tame sometimes because your rf is everywhere) if you can run a beam, that will help with rf control immensely.

SOLD! Been wanting one anyway.

[MDYoungblood]

"make sure someone hasn't crossed wire types"

I mean types of wire, aluminum and copper, you stated all copper so your okay there. Running about a hundred feet of coax shouldn't effect anything and what is in the house (protected from the elements) shouldn't be bad, run your hand along the jacket to see if any damage has occurred. Look into those snap ferrite beads I mentioned.
Yes over driving the amp or over driving radio into the amp will cause problems. you could back the radio down and I think that amp is variable so back it down too.
I don't do much AM anymore, I prefer SSB.

3's

Greg

[jessejamesdallas]

Ok some history with my comments in yellow

"The electrical wiring making noise" - yeah its friggin weird. I thought it was a bad outlet at first. Seemed to be coming from one outlet. Replaced it and nothing changed
"mainly where the noise is the loudest." - Well when I really get on the mic, it sound like it's coming from 3 walls. Two exterior and one interior all have outlets. Really hard to pinpoint a single location.
"check out every electrical connection in the house, particularly that master bedroom, somewhere is a loose connection, wire nut needs tightening, a receptacle screw loose" GOOD ADVICE! Need to crawl around in the attack and see if there are any junction boxes that need attention and pull all the outlets and switches and check them.
"make sure someone hasn't crossed wire types" you mean you mean like swap common and hot? I used one of those 3 light testers on every outlet. Seems ok
"aluminum and copper" All copper thank God
"Separate the antenna system grounding/bonding from the electrical ground - I assume you mean the house electrical ground. Did that. Tried every combination I could think of with absolutely no change in condition.
"don't have them both on the same ground rod outside, add another rod, they can be close but I'd keep them as far apart as possible" Shack is 60' from antenna at the other end of the house.
"amplifier and radio together on the same power supply" Ok I'll separate them and see what that does.
"quality amateur amplifier " Been thinking about that too. This Texas Star is about as bare bones as you can get. No protection or filtering of any kind.

I'm starting to think I'm splattering due to over-modulation. Crap goes in - crap comes out X 100. I'll have an o-scope in about a week so I can check if I'm flat topping or pinching the carrier. Making a tap now.

Just wondering if it's actually the wiring making the noise...or a breaker switch in the breaker box...If a breaker is loose, high RF could make it sing...or in this case..."Talk"...

...right before it shorts out and catches fire...

Well the breaker box is on the opposite corner of the building.
Pardon my ignorance but...
What does "breaker is loose" mean exactly?
And…
Are you joking about the fire?

Thanks everyone

The electrical breakers are mounted on two poles inside the box....after time they can get work loose or just plane wear-out at which point the least little thing can cause them to make noise's or buzzing sounds...If not replaced or if loose, tighten back-up, yes they can catch on fire!

Had this happen to me during the Superbowl in 2015...Right after halftime the power went out, and while walking around the house trying to figure out what happened, I noticed smoke coming from the electrical meter on the side of the house....Called the Fire Dept, they came out, and then we found the several of the breakers had shorted out, and burned up about a dozen more...

Luckily the wall didn't catch on fire, but had to replace all 32 breakers, the breaker box, and the house smelled like melted plastic for months...

Electrician told me you should replace those breakers every 10 years...I have never herd that before, and mine were closer to 30 years old at the time.

Guess easy way to fine out if that's were the buzzing is coming from would be to stand by the breaker box, then have someone key-up the radio and see if the noise comes from there...

[Gus Chiggins]

I didn't go in the attic yet. The noise is pretty much coming from the walls not the ceiling light.
Crawled around under the house today and found the circuit that feeds all of the bedroom outlets. It runs around daisy chaining from one outlet to the next and also covers the other 2 bedrooms. The odd thing I found was that the next outlet towards the breaker box from that master bedroom was in one of the other bedrooms. The whole rest of my hose is white Romex cable but at this outlet this run changes to a black jacketed Romex cable. So it must have been pieced in at some point since 1979 when this house was built. I found no junction boxes.
My best guess on why the black wire... That end of the house has never been remodeled but the other end near the breaker box has. They probably cut that leg to add more outlets on the original breaker in the remodeled section and pieced in that black leg to get the bedroom outlets back to the breaker box. I see nothing sketchy but I'm going to yank that outlet and check the connections tomorrow. All hots and commons are in the right places.

Went and pulled the panel off the breaker box and found that black cable and the breaker it is terminated on. Nothing strange about it except that is an oddball having black jacket. All copper even the black one.

So I got out my screwdriver and started checking screws. The common legs were all fairly tight but there were many hot legs on the breakers that I was able to tighten over 1/2 turn. Kind of surprised me. The black one was one of the least tight screws at about 3/4 turn. Not exactly loose but I consider a one handed twist of the screwdriver over 1/2 turn to be not tight enough.

Glad I checked even if its not related to my radio problem. loose=resistance=heat=fire ... not good. Thanks for the advice Jessejamesdallas.

Have not had a chance to test anything radio wise but thought I'd report my findings on the wiring.

[jessejamesdallas]

More than likely your problem is going to be somewhere with connections rather than the wire itself...

Next. I would get someone (wife maybe) to start talking on the radio, then you go around and see if you can still hear the buzzing...check the wall outlets, breakers, ceiling fans, heck even LED Light bulbs could be causing it...

[TNT1450]

aluminum and copper don't mix and can actually cause noise (and a possible fire later) in the system.

They definitely don't mix. Those two metals will interact and cause corrosion, leading to poor connection and a high resistance at the connection. High resistance = heat.

[Gus Chiggins]

More than likely your problem is going to be somewhere with connections rather than the wire itself...

Next. I would get someone (wife maybe) to start talking on the radio, then you go around and see if you can still hear the buzzing...check the wall outlets, breakers, ceiling fans, heck even LED Light bulbs could be causing it...

Yeppers. Next on my list is to pull every outlet and check the connections. Not easy since most are behind pieces of furniture.
Looks like they have all been replaced with those square faceplate style. So somebody has been in there.

I’ll also swap that suspect leg to another breaker to see if that changes anything.

If that doesn’t cure it I’ll put 20’ more height on the antenna with beads and choke.

Anyone seen the GAP Titan DX 8-band center fed antenna? I have one in my “junk” pile. I’m studying for my General ticket anyway and will want other bands eventually. Interesting design. Not ideal but about the same size as my super penetrator so would pass the HOA “Wife” requirement.

Thanks for the help everyone.

[Gus Chiggins]

Well thanks to all the good advice I think its solved. Put 6 snap on ferrite beads at the antenna (mix 31) and wound 4 turns on a ferrite ring between the radio and the amp. No more noise in the bedroom.
I"m still going to pull those outlets and check them but I do believe skin effect was the culprit in this case.
Tonight when she is trying to sleep I'll hammer on it and see if there is ANY noise. If there is maybe couple more beads would be in order.
Also going to work on my grounding when the rain lets up. I know I can improve that.

I'm SUPER happy right now.
Thank you one and all for your advice and comments. What a great site.
73s
Gus

[jessejamesdallas]

Good deal, sounds like your on the right track...Those ferrite beads do work in some cases...My daughter bought a New pair of headphones not too long ago for her computer, and my radio was getting in them, so I snapped a ferrite bead on the cord of her headphones and it solved that problem, so they do work in some cases...

Had another problem with my computer when I would key-up and start talking it would cause my monitor to sorta flicker with wavy lines, the ferrite beads didn't do anything with that tho...Found out later the Amp had a weak tube in it, and once I changed the tube the wavy lines went away...

[Gus Chiggins]

I'm getting on track. +90%there. Still a little noise when I'm up on the mic at full peak. WAY better than it was though.
I'm going to clip some of those beads on the 110VAC leg that's manifesting the noise and see what happens. Also, my coax LMR400 was about 3 inches from that Romex cable. I moved it as far as I could and now I've got about 2' distance between them. If that makes a difference I'll know what to do next. Getting ready to test again.
I need to raise that antenna anyway. Just waiting for more Coax to arrive and when it does I'll re-route it away from the house wiring at the same time. I think I've had a combination of things going on. Splatter, Coax to Romex proximity, Radiating element to Romex proximity, crappy grounds. Everything adds up to a perfect storm I guess.

I think I'll drop a meter between the radio and the amp and look for reflect there. Could have a bias issue with the amp I suppose. Although built in SWR meter in the radio shows low SWR. Those are notoriously unreliable.

[Gus Chiggins]

I've not had a chance to raise that ground plane up yet. Of note though I'm getting a small amount of noise from inside the walls when on SSB with less than 100 watts peak. That is with a clean IC-7100 and no amp! I'm highly suspect of the house wiring at this point. FIRE BAD!
Next step is to pull all the outlets and check the connections.

I'm also re-building my GAP Titan DX antenna which I'll be ground mounting away from the house. No clue if I'll get a usable match on 11m with that but at least I'll get the other bands which I don't have a resonant antenna for today.