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eHam Forums => RFI / EMI => Topic started by: W1DG on February 01, 2013, 06:02:24 AM



Title: Equally spaced carrier on 80 and 160 meters?
Post by: W1DG on February 01, 2013, 06:02:24 AM
Since early this past summer I have been getting S9+ carrier every 21 khz on 160 meters and S8 carriers with same spacing on 80 meters.
Although rather slowly these carriers move up the band.

Thought it was my end fed antenna so took it down and using my Hexbeam I still hear and see it (FlexRadio) although down a bit in signal strength.
I tried rotating the Hexbeam to pinpoint the direction but no matter where it pointed signal was the same strength? Tried a BCB but no change.
Ran an extension cord to my neighbors outside plug and killed the power to my house and noise still there.

Then thinking it may be my radio I took it to a friends house who also has a Flex. Hooked it up there and nice and quiet. Tried walking around the
close neighborhood with portable radio tuned to 160 but unable to find any smoking gun?

It is there 24 hours a day and I am ready to just quit 160 and 80 operation. Just bought a used JPS ANC-4 but haven't really played with antennas
yet. Anyone got any ideas as to what it may be?


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: K5LXP on February 01, 2013, 06:54:01 AM
Step one:  Run the radio off of a battery and kill the main breaker(s) to the house.  Chances are very good the problem is in your QTH.  Going around turning things on and off or "sniffing" with a receiver is hit and miss.  Killing the AC completely will give you your answer in an instant.


Mark K5LXP
Albuquerque, NM


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: W1DG on February 01, 2013, 07:13:45 AM
Mark,

Thanks for the reply! I killed the power to my house yesterday and ran an extension cord to my neighbors outdoor outlet and problem was still there. So I assume that would be the same as using the battery?


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: WB4BYQ on February 01, 2013, 08:00:29 AM
i had a noise like that one time and it was my computer power supply.  maybe the flex radio computer is the problem. 

if not the rfi is coming from a neighbor home from a switching power supply, which inturn
is radiating thru the house wiring for power.

richard


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: W1DG on February 01, 2013, 11:19:12 AM
Richard,

Thanks for the input. I've tried 3 different power supplies for the Flex. Then I completely removed my Sony computer and installed my Imac with windows. All changes resulted in the same noise. Later this afternoon I'll try my wife's Macbook on battery.

I know that my immediate next door neighbor would kill his power for me but not sure on others? Kind of hard to ask as you don't want to open a can of worms.

Don


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: W5LZ on February 01, 2013, 12:08:21 PM
Using your neighbor's AC power is the same as using your AC power, comes from the same power source.  It isn't the same as using a battery for powering your equipment.  If the noise is coming from the AC line you haven't eliminated it by using your neighbor's AC line.
 - 'Doc


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: W1DG on February 01, 2013, 06:07:43 PM
Richard,

I was unable to run the Flex withe Macbook as it has no firewire port. Did disconnect all computers and with my FT-100D I still have the same problem

Doc,

Thanks for the input but the first thing I am trying to find out if the noise is coming from something in my own home. That is why I plugged into my neighbors AC. Not looking for line noise yet but maybe should start?

Don


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: SIGINT11 on February 02, 2013, 10:33:49 AM
Is it just a carrier or do you hear anything?  I had a invisible dog fence from a house next door that was similarly spaced.  It affected everything from 0hz up to the 60 meter band,  It even wiped out 770 wabc which is the strongest AM station near my QTH.   


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: W1DG on February 02, 2013, 11:07:32 AM
It is just a carrier and I only hear that. Tried tuning to see if maybe it was a harmonic but no. Thanks for the idea about invisible fence. There are a couple of possible houses very near that may have that. I'll try to check it out.

Thanks
Don


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: KQ6Q on February 06, 2013, 08:46:21 PM
See if you can pick up one of these carriers on a portable AM radio - a walkman, or a portable SWBC radio. use the portable as a walkaround search unit - low band transmitter hunting, see where the signal is loudest. it might even be the charger for an electric scooter or children's toy in the neighborhood.


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: KJ7YY on February 13, 2013, 07:50:30 AM
Sounds like the neighbors invisable dog fence.  I had a very simular noise and did all the things mentioned here.  A fellow ham that works for the power company found the noise after fixing grounds and transformers on thier service.  The dog fences are so noisy that the company has a kit available to fix the problem!  My neighbor was very co operative, installed the noise kit and the problem is gone. 


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: KC5AOS on April 22, 2013, 01:26:55 PM
try shorting the antenna connector on the back of the rig and see if the problem goes away.  If it doesn't, it is a rig problem, if it does go away, than resume your hunt.


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: WV4I on April 25, 2013, 09:42:40 AM
I also get a carrier/steady signal every 19kc or so, moves up and down bands, with different strengths, different times. It does appear sometimes all at once like something turning on. It's not my pool or irrigation pump, or my a/c. It's viewable on spectrum using SDR-Radio and SDR-IQ, also can be heard on TS-590S. I simply avoid affected freqs or can sometimes work over top of it, but would love to know source.


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: WV4I on April 26, 2013, 01:53:51 PM
I just figured out that my 19kc spaced spurs ? IS from each of my A/C units. Not sure if air handlers in garage or outside units, or combo. The units RFI is offset by about 5kc between units, but both produce spurs 19kc apart.

At turn on single line on SDR-Radio screen which gradually grows to mult lines per spur, wider, etc. Worse at higher freqs. Much worse on closer antenna to A/C units vs one on other side of house, direct line blocked.

Unplug antenna and goes away.

Not too concerned, just work around, but if someone else sees this phenomenon, then check the A/C units or air handlers? Note my pool and irrigation pumps create no RFI.


Title: RE: Equally spaced carrier on 80 and 160 meters?
Post by: WV4I on May 14, 2013, 04:32:06 PM
Just discovered I have ECM type motors turning fans in air handler units. Likely the culprits. ARRL sent me a pdf with the usual fix. However, this RFI is worse with higher freq, unlike thread starters issue, but also equally spaced products on spectrum display of SDR.

When I get time to deal with this I ll post an update.