Author Topic: Home generated RF interference...  (Read 1651 times)

Looking-Glass

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Home generated RF interference...
« on: September 07, 2017, 0129 UTC »
Moving house is bad enough but to find two lots of severe interference all over HF at the new residence adds another challenge.

First lot of spurious noise was all over much of HF, using the Tecsun S-2000 the source was found to be the gas heating "Seeley MagIQtouch" LCD control panel in the lounge room which is wired direct into the mains power and thus runs 24 hours per day.  Crawling under the house I disconnected it and some form of peace for the time being.

Second comes and goes, with spurs every 8KHz or so from 3MHz through to 18MHz up to 10dB over on the meter.  Faint clicking noise in background noted. Runs for around 3 to 8 minutes then vanishes.  Source was found, yet again using the faithful Tecsun S-2000.  Surprised to find the source was our brand new Samsung "Digital Inverter Technology" refridgerator in the kitchen.  Noise was 20dB over near the appliance, turned it off at the wall point and interference was gone.

All this modern technology is emanating interference on HF, I wonder what else we can add to the list? ???
Mount Piddington, NSW, Australia 3,654 feet ASL (127kms west of Sydney)

Grid Square:  QF56dj.

Yaesu FT-2000D & Tecsun S-2000 to 310 feet of wire, and a multi band vertical of dubious reliability.

ChrisSmolinski

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Re: Home generated RF interference...
« Reply #1 on: September 07, 2017, 0950 UTC »
Our "inverter" technology Panasonic microwave causes RFI, but fortunately only on the 2.4 GHz WiFi band. We have a dual band router, so 5 GHz is unaffected. I assume at least in the case of your fridge the "inverter" part means using an inverter to run the compressor motor?

IIRC the FCC regs have a blanket exemption for appliances, they do not need to adhere to any RFI limits.
Chris Smolinski
Westminster, MD
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skeezix

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Re: Home generated RF interference...
« Reply #2 on: September 07, 2017, 2207 UTC »
IIRC the FCC regs have a blanket exemption for appliances, they do not need to adhere to any RFI limits.

So I stick my 500W 43m transmitter in the fridge...
Minneapolis, MN

Looking-Glass

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Re: Home generated RF interference...
« Reply #3 on: September 08, 2017, 0450 UTC »
Been on the Samsung web site viewing the refridgerator details (no manual these days with the unit, have to download as PDF) and not much help at all.  May have to place a call with the service toll free hotline.

Spurs are strongest on the 7, 8 and 9MHz bands with the needle plus 10dB, something has to be done. 

Failing a resolve will just have to turn it off at the wall to pull out weak signal DX, then remember to turn it back on! ::)
Mount Piddington, NSW, Australia 3,654 feet ASL (127kms west of Sydney)

Grid Square:  QF56dj.

Yaesu FT-2000D & Tecsun S-2000 to 310 feet of wire, and a multi band vertical of dubious reliability.

Josh

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Re: Home generated RF interference...
« Reply #4 on: September 08, 2017, 1458 UTC »
There are noise filters that can be placed inline with the power cord, and you can always place ferrites on the cord. Mfj makes a brute force ac filter but dunno if it will handle fridge startup current. I wonder if you could faraday cage the main board or something.

redhat

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Re: Home generated RF interference...
« Reply #5 on: September 08, 2017, 1838 UTC »
If its inverter drive, sometimes the switching transients get into the frame of the fridge and use it as an antenna.  AC line filters can be had for around $20 USD on ebay, just search for 'AC line filter'.  That will probably be cheaper than going through a parts house.  Fortunately on 240VAC, the fridge shouldn't draw more than a few amps.  Select the filter with the lowest cutoff frequency you can find.  This should help the problem.  If more attenuation is needed, you may have to load up the inverter output leads to the motor with ferrites.

Good luck!

+-RH
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Looking-Glass

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Re: Home generated RF interference...
« Reply #6 on: September 08, 2017, 2248 UTC »
Thanks Josh and Redhat, hopefully one of the options will give some form of result... ::)
Mount Piddington, NSW, Australia 3,654 feet ASL (127kms west of Sydney)

Grid Square:  QF56dj.

Yaesu FT-2000D & Tecsun S-2000 to 310 feet of wire, and a multi band vertical of dubious reliability.

Mr.ArchVile

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Re: Home generated RF interference...
« Reply #7 on: September 09, 2017, 2117 UTC »
I found myself, E-cigs 3rd generation type.

I will point out though they have to be very close to the reciever.

ThaDood

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Re: Home generated RF interference...
« Reply #8 on: September 11, 2017, 1054 UTC »
          For septic here, we have a Clearstream septic tank / UV purifier system. Unfortunately, that power supply for the underground UV light purifier spectrum-wide threw hash of over S9 from LF to to the 6M band. So, two .1uF 250VAC CAPīs, one on terminals of the UVīs AC input, and the other on the UVīs DC output. Now, you have to have a portableīs antenna right over that UV power supply to hear that hash. Panasonic appliances are also notorious for spectrum-wise spurs from DC to light. Heavy investment into ferrite chokes helps to a degree. Then, thereīs DSL MODEMīs. Ferrite chokes on every cabling going to and fro that unit. Then, thereīs CFLīs and LEDīs lighting cheap power supplies. Choke them, where ya can. Now, the AC BZZZZZZZZZZZZZZZZZZZZZZZ that comes from the band-aid fixes from the utility power lines? Move your antennas as far as possible away from that, since the power companies will not want to spent one cent of their quarterly bonuses to have to fix those. And I can hear that all the way into the 222MHz band. Grrrrrrrrrrrrrrrrrrrrr.....

Looking-Glass

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Re: Home generated RF interference...
« Reply #9 on: September 13, 2017, 0428 UTC »
Yesterday I set up the Yaesu FT-2000D base radio in the garage at the back of the house and no noise from the refridgerator.

However, noise still 10dB over with 8KHz spurs on the Tecsun 2000 across HF, set up in the spare bedroom of the house, switched to battery power but no change.

Probably the Chinese made Tecsun lacks the professional integrity of the big Yaesu when it comes to filtering and dealing with noise?

Incidentally, they both use the same wire antenna.
Mount Piddington, NSW, Australia 3,654 feet ASL (127kms west of Sydney)

Grid Square:  QF56dj.

Yaesu FT-2000D & Tecsun S-2000 to 310 feet of wire, and a multi band vertical of dubious reliability.

Josh

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Re: Home generated RF interference...
« Reply #10 on: September 13, 2017, 1622 UTC »
Some ferrets on the ac line to the fridge might help dampen them waves. I assume the ac line is carrying the rf to the rest of the house wiring.

MDK2

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Re: Home generated RF interference...
« Reply #11 on: September 13, 2017, 1924 UTC »
Some ferrets on the ac line to the fridge might help dampen them waves. I assume the ac line is carrying the rf to the rest of the house wiring.

Someone call PETA.  ;D
Denver, CO.
Grundig Satellit 750, Tecsun PL-600, SDRPlay RSP2 Pro.
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Soon to include RA0SMS mini-whip, but need mounting before that goes online.
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Looking-Glass

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Re: Home generated RF interference...
« Reply #12 on: September 14, 2017, 2235 UTC »
Josh, the Tecsun 2000 is running off batteries and thus not connected to the mains power, also not coming through the FT-2000D in the garage running off mains.

MDK2: PETA? Is that the Australian version of RSPCA (Royal Society of Prevention of Cruelty to Animals) in the States? ;D

In country areas of Australia at local fairs there is a competition about "shoving a ferret down your pants" endurance test... :o

There was a Vietnam war movie some years back with the VC shoving rats down a mans pants in a torture scene, so rats or ferrets?

Samsung telephoned yesterday and said the appliance was "Approved for Australian Standards" under the import regulations, however, a Samsung technician will call in and check the refridgerator some time next week free of charge whilst in this area.
Mount Piddington, NSW, Australia 3,654 feet ASL (127kms west of Sydney)

Grid Square:  QF56dj.

Yaesu FT-2000D & Tecsun S-2000 to 310 feet of wire, and a multi band vertical of dubious reliability.

ChrisSmolinski

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Re: Home generated RF interference...
« Reply #13 on: September 14, 2017, 2320 UTC »
I prefer People Eating Tasty Animals  ;D
Chris Smolinski
Westminster, MD
eQSLs appreciated! Send to: csmolinski@blackcatsystems.com
JRC-NRD 545 / RF Space netSDR / 670 ft horizontal loop / 500 ft beverage / 43mb sloping folded dipole / 7' x 7' Loop

MDK2

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Re: Home generated RF interference...
« Reply #14 on: September 15, 2017, 0445 UTC »
Denver, CO.
Grundig Satellit 750, Tecsun PL-600, SDRPlay RSP2 Pro.
two homebrewed mag loops (10' and 15' circumference).
Soon to include RA0SMS mini-whip, but need mounting before that goes online.
eQSL's appreciated, wickerjennie (at) gmail