Print

[N1AUP]

I have a Windom antenna up about 40 feet.  I'm seeing noise on my S meter that is running at S9 or higher on 40 and 80 meters.  Nothing on 10, 15.  Some on 20.

Is this normal, or is there some piece of equipment hashing my reception?

Thanks
N1AUP

[K0UA]

I have a Windom antenna up about 40 feet.  I'm seeing noise on my S meter that is running at S9 or higher on 40 and 80 meters.  Nothing on 10, 15.  Some on 20.

Is this normal, or is there some piece of equipment hashing my reception?

Thanks
N1AUP

Not normal where I live.  Especially on 40, typically s1 or 2 without any preamps. I assume you are not running preamps.  80 might be S5 at times.  Depending on static crashed that might be propagated into my area.  Of course If I have static crashes in my area I am at S0 because the radios will be turned off

Start by getting the radio on battery power.  Then turn off the main breaker to your own house.  Note the noise. If it drops significanty, the turn back on the main breaker, does it come back?  Then start flipping breakers one at a time. find the room or service that causes the noise, then start unplugging things  one at a time.

If the problem is not in your house, uh oh...

[N1AUP]

I do have battery backup, and can kill the power to the whole house.  Could LED streetlights be causing hash?  Or is it more likely a high voltage arcing situation?  Should I try driving around my neighborhood with an AM radio tuned between stations?

I just hope it's not neighbor stuff. 

Thanks.

[K0UA]

I do have battery backup, and can kill the power to the whole house.  Could LED streetlights be causing hash?  Or is it more likely a high voltage arcing situation?  Should I try driving around my neighborhood with an AM radio tuned between stations?

I just hope it's not neighbor stuff. 

Thanks.

The neighbors LED pole light causes broadband hash when I drive near it with my mobile rig. It sounds like a Prius automobile.  I can hear a Prius coming down the road before I can see it.  It doesn't seem to bother my home station. I have several unstable carriers on various bands that sound like switching power supplies that come out of neighbors houses, but this is not broadband hash.

I don't know what a bunch of LED streetlights would do. It would depend on their power supplies and how well they are filtered.  The LED's themselves make no noise, but the switching power supplies sure can. There is a special place in **** for the inventor of the switching power supply. Actually switching power supplies CAN be made virtually noise free, I have two of them in my ham shack powering my radios, but they often have no filtering installed and radiate freely.

[N1AUP]

I killed the power to the entire house, and ran off of battery, and the noise was S5 - S7 on 40 and 80. 

[G8YMW]

Now comes the good bit.
Nailing the bits in your house that are causing the qrm.
I presume you switched off individual circuits in your house noting which ones are making a difference?
Then checking which appliance is causing noise (unplugging / switching off)?

You have to clean your house up first  before even thinking about going walkabout with a portable radio

[KF9BD]

I can attest to the process described here.  I am going through the process to isolate and mitigate noise as well.  I have used Mix 31 chokes on several items in my home and have reduced the noise level significantly across the bands.  The strongest noise maker was and is the incoming Comcast cable.  The noise from the cable is in the 14 mhz range and running -82 dbm.  The process takes time, but, can allow one to improve the signal to noise ratio.  Just keep at it.

Danny - KF9BD

[K0UA]

Also keep in mind a Windom (OCFD) is a very "noisy" antenna.  I have one. The problem with them is they are plagued with common mode current issues which also helps your coax pickup all the hash coming out of your household "garbagemakers" (Switch mode power supplies mostly).  In addition to the 4:1 balun you have now on your OCFD, is putting a GOOD 1:1 choke in line also.  This will help with common mode on both transmit AND recieve. 

But it is good to get rid of the radiators in your home.  Start tracking them down one by one.  Buy some mix 31 ferrites. Beware of bargin ferrite.  If it doesn't say what the mix is, then they are no good.

[N1AUP]

I did not include a choke, but I did buy the parts to make one this weekend.  Curious how you deal with the cable TV line?  I don't have TV, but I do have Internet. 

[K0UA]

I did not include a choke, but I did buy the parts to make one this weekend.  Curious how you deal with the cable TV line?  I don't have TV, but I do have Internet. 

Take an FT240 size ferrite of mix 31 or mix 43 and wrap as many turns of the RG6 cable TV coax thru it  as you can.

[N1AUP]

Thanks.  I'll try it.

I also think I'm going to try disconnecting the cable at the pole, to see if the interference drops.  My connector is at ground level.

Chris

[N1CX]

Chainsaw to the pole 

[KI3R]

Had same nasty problem years ago.  Ground connection at box was loose.  Issue resolved BUT with all the so called "compliant" junk out there ... well.  I get severe noise intermittent from extra house source  ... sounds like the good 'ole aquarium heater.  Take care ...  Tom   KI3R   Belle Vernon PA      ps  just got a new AWD Prius yesterday but no radio in car  .....  XYls  baileywick  ....

[K0UA]

Had same nasty problem years ago.  Ground connection at box was loose.  Issue resolved BUT with all the so called "compliant" junk out there ... well.  I get severe noise intermittent from extra house source  ... sounds like the good 'ole aquarium heater.  Take care ...  Tom   KI3R   Belle Vernon PA      ps  just got a new AWD Prius yesterday but no radio in car  .....  XYls  baileywick  ....

Many of the new electric cars do not include AM radios.  As the cars cannot be made quiet enough to support the install of an AM radio.

[WD4ELG]

K0UA nailed it.  My antennas are all fairly quiet except my off-center-fed dipole and my end-fed half wave.  Both are notorious for common mode in certain cases from what I read, and that's certainly the case for my QTH.