HFU HF Underground
General Category => General Radio Discussion => Topic started by: ChrisSmolinski on September 27, 2016, 1920 UTC
-
For almost the past week, I had a horrible problem with QRM on the long wave band, particularly the DGPS band. The background noise level would increase several S units.
I used my Sony 7600G portable and went around the house, looking to see where the interference increased or decreased. (I first checked outside to verify that the strength decreased as I got further away from the house, to confirm the problem was here and not with a neighbor). I noticed that it would increase if I put the radio next to the wall were wiring ran, suggesting it was being conducted (and then radiated) by the AC wiring. It took a while, but this morning a finally found the culprit - a failing CFL bulb in the range hood in the kitchen (which is always on). I have many CFL bulbs in the house, and otherwise do not have problems with them causing RFI. This bulb apparently started to when it began to fail.
The offending bulb:
(http://i.imgur.com/a67pALi.png)
Here is a waterfall from the SDR, showing first the light switched off, then on, then off again. You can see the dramatic increase in the noise floor. Around 200 kHz, it was close to 20 dB.
(http://i.imgur.com/uqhLElb.jpg)
-
Congrats!
-
Ya, I have trouble with these peskie little bulbs every so often, as recently as August. Couldn't figure out what was hammering the low end of the broadcast band (actually more than just that portion). Guess what, one large fancy colored outdoor bulb on the garage :P
-
I had one turn purple color on me... maybe too much mercury... acted and sounded like an old mercury vapor tube... kept it but I don't know why... it's in a box well hidden from the Lady of the house.
-
I've seen enough of the cfl bases that burst into flame to never leave them on unless I'm right there with them. Most of them here seem to only create noise if the radio or antenna's within a few feet of the bulb.
-
You said it Josh.
A lot of the cheap ones have inadequate vent holes for the ballast in the base. When they go, it can be spectacular. A lot of underage weed growers burn down the folk's house use the things in the back of their closets. Old wiring combined with poor ventilation and lots of poorly designed bulbs stuffed in a damp confined space, what could possibly go wrong?
Still, they're not as bad as the halogens in the torchiere lamp craze a couple of decades back. That was "How To Burn Your House Down:101".
-
I have none of those things as they are prohibited from my house. LED lamp, I have one and it seems acceptable. But those things are expensive (and they still pump out the heat).
I stocked up on incandescents a while back and should be good for quite a while. Not any worse than my tube radios. Was listening to a National NC-183D tonight.
-
(http://i.imgur.com/a67pALi.png)
There are several 2nd. hand stores within walking distance & those things are plentiful. As for the above offender I say simply "Hammer! I repeat: Hammer!!"
-
You said it Josh.
A lot of the cheap ones have inadequate vent holes for the ballast in the base. When they go, it can be spectacular. A lot of underage weed growers burn down the folk's house use the things in the back of their closets. Old wiring combined with poor ventilation and lots of poorly designed bulbs stuffed in a damp confined space, what could possibly go wrong?
Still, they're not as bad as the halogens in the torchiere lamp craze a couple of decades back. That was "How To Burn Your House Down:101".
I loved my torchiere lamp! Yes it made some heat but it lit up the living room wonderfully. Also yes do not leave the room for a length of time with that thing on, Also I think it made rays that burnt my eyes. And don't hammer the bulb, it can be used as a neat rf sensor if you have a transmitter handy to excite it.
:D
-
Toss them like a handy Gran-aid into an enemies house then call the EPA on them... It's called hazmat folks! No kidding, Never have CFL's where there are or might be children... sharp glass and mercury don't mix... the former hurts like all get out and the latter cause one to be a retard... ;-) I otter know! ::)
-
Toss them like a handy Gran-aid into an enemies house then call the EPA on them... It's called hazmat folks! No kidding, Never have CFL's where there are or might be children... sharp glass and mercury don't mix... the former hurts like all get out and the latter cause one to be a retard... ;-) I otter know! ::)
Just finished re-reading "No Commercial Potential", Frank relates how his dad brought home vials of Mercury!!! & he would hit the stuff (after pouring onto the floor)
with a Hammer! I repeat: a Hammer! He remembers dusty balls of mercury under his bed.
-
Had a CFL that worked fine... Except it was plastering the AM band with the worst electrical AC hash imaginable from 680 khz or so all the way down to the bottom of the band.
I took a portable digital SW-AM-FM radio around the house and finally found it, almost by accident. Finally, in frustration, I began switching off lights and circuits in the house.
It was one of my porch lights. From looking at it, you wouldn't know it was the culprit.
-
Toss them like a handy Gran-aid into an enemies house then call the EPA on them... It's called hazmat folks! No kidding, Never have CFL's where there are or might be children... sharp glass and mercury don't mix... the former hurts like all get out and the latter cause one to be a retard... ;-) I otter know! ::)
Just finished re-reading "No Commercial Potential", Frank relates how his dad brought home vials of Mercury!!! & he would hit the stuff (after pouring onto the floor)
with a Hammer! I repeat: a Hammer! He remembers dusty balls of mercury under his bed.
We used to break the ends off of thermometers at school when I was a kid and watch the stuff roll back and forth on our desks. If you got cut doing it, the school nurse had good old mercurochrome to put on the cut.
-
Wow, i don't have those lights inside my room, they are just the normal ones.