HFU HF Underground

Technical Topics => Equipment => Topic started by: WA4FHY on October 14, 2017, 1937 UTC

Title: Do it TO yourself RFI !
Post by: WA4FHY on October 14, 2017, 1937 UTC
Late last year, I was in Home Depot (it’s not a proper weekend without at least one trip to Home Depot and / or Lowe’s) and bought a Halloween light that was on sale at half price ($10); it projects the likeness of witches flying around on, on the side of your house. It is a #1001 261 470 “Whirl-A-Motion” projector; they had similar ones that projected ghosts or jack-o-lanterns. Yesterday evening I thought Friday the 13th would be a good day to set it up for the first time, in the front yard. That was easy enough to do and it was interesting to watch. I came inside and noticed that there was terrible noise from at least 75 meters until it finally disappeared into the S7 noise floor ~8 mHz (see attached screenshot).  I thought of what might cause it; I was pretty sure it was something nearby and I unplugged the projector and the noise went away! I’m not going to fool with trying a toroid on the power cord; I guess that projector will go into the pile of "it seemed like a good idea at the time".
Title: Re: Do it TO yourself RFI !
Post by: Josh on October 15, 2017, 1551 UTC
Lol key it and start a pirate cw station, however broadbanded it is!
Title: Re: Do it TO yourself RFI !
Post by: skeezix on October 17, 2017, 2235 UTC
Did you happen to see what the range is of this low power jammer?

Title: Re: Do it TO yourself RFI !
Post by: ChrisSmolinski on October 17, 2017, 2243 UTC
Did you send yourself a QSL?
Title: Re: Do it TO yourself RFI !
Post by: WA4FHY on November 12, 2017, 2230 UTC
Cute, Chris! No, I didn't QSL myself. Howsomever, I have seen the same
device, in the same packaging but with different configurations in other
stores around here. Most of them are now colored balls and other
Christmas (no, not my cat, Christmas) themes.
Title: Re: Do it TO yourself RFI !
Post by: BoomboxDX on November 15, 2017, 0350 UTC
Sounds like it was a cool device for Halloween, at least.

I wonder how far the RFI reached. Blocks? A mile or so?

My neighbor's psycho washing machine at least reached two blocks or more -- that was into my short indoor antenna. I'm certain that if someone another two or three blocks away had a longer antenna they probably heard the alien noises over half the HF spectrum also.
Title: Re: Do it TO yourself RFI !
Post by: Finman on November 15, 2017, 1700 UTC
I gave up hunting down local noise sources years ago because there are just so many, it became overwhelming. That being said, if I suspect a noise source is internal to my home, then I will try and hunt it down but if it's coming from neighbors homes  ??? ....

I've been using these for many years now and they work great.

http://www.timewave.com/support/ANC-4/anc4.html (http://www.timewave.com/support/ANC-4/anc4.html)

http://www.mfjenterprises.com/Product.php?productid=MFJ-1026 (http://www.mfjenterprises.com/Product.php?productid=MFJ-1026)

The only thing you have to deal with is re-tuning when you change rcv frequencies.
They also can be useful for nulling out unwanted stations depending on the connected "noise antenna"
Title: Re: Do it TO yourself RFI !
Post by: ChrisSmolinski on November 20, 2017, 1306 UTC
Oddly enough I received a spam email today about Christmas lights, claiming no RFI:

Quote
Please could you see following our latest Copper wire Led starry bulb and 3D colorful Led Filament bulb, No UV or IR radiation, No Flicker and electronic noise,which is widely using  for Christma day ,  cafe bar , party , wedding , show store , various decoration and so on.  If there is any possibility in your market, please let us know freely, then we will send you the pricing and tech data in details.
Title: Re: Do it TO yourself RFI !
Post by: redhat on November 22, 2017, 1337 UTC
I bought a string of LED multicolored lights several years back and tested them.  I could hear no noise emission, they do flicker like crazy though.

+-RH