Certainly very unlikely that there is cable TV in that village. It was only rolled out in larger towns as was done on a franchise basis.
Well....
Years ago when there was analog TV I had some bad zebra like interference on my TV for many weeks. It happened mostly in the evening and the weekends. At that time local radio stations were proliferating around without regulation and I thought it could be one of them.
One day I called Anacom (Portuguese communications regulatory office) and they came with an antenna in a van & by triangulation they found the source.
It was one of my neighbors mast antenna amplifier which was oscillating.
When they cut the meter power to that house the interference disappeared.
Turns out, during the day there wasn't anyone in house watching TV since they were at work.
Years ago when there was analog TV I had some bad zebra like interference on my TV for many weeks. It happened mostly in the evening and the weekends. At that time local radio stations were proliferating around without regulation and I thought it could be one of them.
One day I called Anacom (Portuguese communications regulatory office) and they came with an antenna in a van & by triangulation they found the source.
It was one of my neighbors mast antenna amplifier which was oscillating.
When they cut the meter power to that house the interference disappeared.
Turns out, during the day there wasn't anyone in house watching TV since they were at work.
The coffee pot story is great. While I haven't seen it in decades, you could sometimes achieve the same with an ordinary wall light switch. Sometimes "half-on" would produce a flickering arc in the lamp and you could hear the static on the FM (so Steely Dan lied.)
Reminds me of the very early days of radio, when they used something called a spark gap. Imagine how popular you'd be with the FCC (or your country's equivalent) if you built such a thing as a working model 🙂
Reminds me of the very early days of radio, when they used something called a spark gap. Imagine how popular you'd be with the FCC (or your country's equivalent) if you built such a thing as a working model 🙂
Some of my early experiments involving high Gm tubes connected to high Gm mosfets wiped out all reception in the house, AM, FM and even digital TV. I have yet to tame those beam regulator triodes that have a Mu of 300 and a Gm of 50,000.
Reminds me of the very early days of radio, when they used something called a spark gap......You can build a Tesla Coil...
Back in high school (1968) myself and some friends decided to build a big Tesla Coil, modelled after the "Big TC" plans published in Popular Electronics magazine in the mid 60's. It was to be entered in the school science fair.
As was my style even back then, we decided to make it BIGGER. The transformer was only known by the name "Budweiser" since that's what was painted on its side, and it was huge. It took two of us to move it. The secondary coil was nearly 5 feet tall. When we fired this thing up an evil sound came out of the school wide PA system and all TV and radio reception ceased for several blocks surrounding the school. The same sound came from radios and TV's.
The science fair officials decided that the spark gap was "not safe" and we could not put this thing in the science fair unless it was enclosed. The teacher got the shop class to make an enclosure out of clear plastic, so we put this monster in the fair. All testing had been limited to a few second bursts due to the immense interference it made.
So, on the night of judging for the fair we fired it up. The racket made by the spark gap got everyone's attention and a crowd gathered as I proceeded to light up an 8 foot fluorescent light tube from two feet away. Things were fine for about a minute until the arc inside the plastic box turned into some kind of purple plasma, at which point the plastic box started melting, then burst into flames. Fire extinguishers were drawn and the evil Tesla Coil was dead forever. Using a Fire Extinguisher in a school brings forth an "incident report" and a ton of paperwork, resulting in the 4 of us being forever banned from the science fair.
Fast forward about 30 years and I helped my daughter do entries for the science fair all through her middle and high school years. Most were mundane entries detailing the build of a TV satellite dish, or making scientific measurements like "which brand of pop corn has the highest pop success rate."......Until the momentous "Foods That Go Boom" entry. This one won the school fair, then won the county fair, but someone in Tampa pulled it from the State Science Fair. It seems that they decided that blowing the door of a microwave oven open by nuking an egg was bad, but blowing the door off the oven by nuking a whole carton, was really unsafe. Never mind the neat demonstration of "supercritical fluid."
Brings to mind fond memories of the “Alpha 336 incident” at USF. I got a letter from the housing department about concerns of “sounds of arcing and sparking coming from your room”, and “bright flashes which were observed on the ground”. Nothing was harmed during this incident, except a bunch of scrap metal and a few expendable capacitors were stressed, but it looked and sounded nasty enough to get them to insist that I install a “breaker panel for my experiments”. Me and my partner in crime laughed our ***** off when I got that letter.
So what was going on? Just the “Spark-o-Matic”, a big bank of soup can electrolytics from Skycraft connected up to bus bars and charged to exactly 75 volts with a transformer (to stay within ratings). 10 100-watt colored PAR lamps which were normally my disco light system functioned as the dim bulb limiter. That was most of the flashing they saw - but it did throw off huge showers of sparks from the molten metal. And it was as loud as the speakers. So when they insisted on a breaker panel, I just yanked the dryer plug off my homeboy distro, wired a standard plug to both phases, and proudly hung it on the concrete wall (with drilled in concrete anchors).
So what was going on? Just the “Spark-o-Matic”, a big bank of soup can electrolytics from Skycraft connected up to bus bars and charged to exactly 75 volts with a transformer (to stay within ratings). 10 100-watt colored PAR lamps which were normally my disco light system functioned as the dim bulb limiter. That was most of the flashing they saw - but it did throw off huge showers of sparks from the molten metal. And it was as loud as the speakers. So when they insisted on a breaker panel, I just yanked the dryer plug off my homeboy distro, wired a standard plug to both phases, and proudly hung it on the concrete wall (with drilled in concrete anchors).
I remember several years ago i had a home made tube kit stereo 16w which i used on my hifi speakers just for fun, it didnt sound that good but anyway i had a problem at random times spent weeks trying to track down the source of audible pops and strange sounds when someone i work with told me to isolate it from the mains as a test, so i ran it on a set of batteries which i coupled to get the 200v and sure enough it was all gone.
So i knew it was mains but not where from so i shut off everything in the house and it was still there, anyway months later i was playing it loud ignoring the pops and when i went outside a few days later, the neigbour whos window was very close to where my hifi was said that he could here those pops everytime he turned his powerline adapter for internet at his tv box on, so i googled what it was and it said it sends the internet through the mains cabling but this is another house!
Anyway i set the amp up with a small speaker outside on an extension lead and the neighbour opened his patio door and played with the powerline adaptor and sure enough it was always when it was switched on, either one of them since he had two as a pair.
Pretty bad really for anyone with sensitive audio gear.
So i knew it was mains but not where from so i shut off everything in the house and it was still there, anyway months later i was playing it loud ignoring the pops and when i went outside a few days later, the neigbour whos window was very close to where my hifi was said that he could here those pops everytime he turned his powerline adapter for internet at his tv box on, so i googled what it was and it said it sends the internet through the mains cabling but this is another house!
Anyway i set the amp up with a small speaker outside on an extension lead and the neighbour opened his patio door and played with the powerline adaptor and sure enough it was always when it was switched on, either one of them since he had two as a pair.
Pretty bad really for anyone with sensitive audio gear.
I made something similar, also with 4 or 5 of BIG caps from Skycraft. Back in the early 70's when Skycraft was still a disorganized mess of boxes I found a BIG cap. It was about a foot long and 4 or so inches in diameter. It was a few tens of microfarads at a voltage high enough to be charged directly from rectified wall outlet (don't remember the details). When I asked how much, the man said "all of those caps are $2 each." I proceeded to dig through all of them to find 4 or 5 with the same ratings. I also found a suitable rectifier, so the total cost of my experiment was well under $20. Of course it tripped the breaker the first time I plugged it, so I wired a 100 watt light bulb in series with the wall plug.
I had a lot of fun blowing stuff up, lighting up the world with a couple of carbon rods from D cell batteries, and launching small metal objects with the coil removed from a very large power supply choke and a starter relay from an old Mustang.
The fun ended when one cap decided to short out and the stored energy in all of them blew the side off the bad cap.
I had a small version of this in my desk for several years at Motorola. It had about 10 X 10,000 uF @ 35 volt caps in parallel wired with #12 house wire. It was useful for finding and sometimes fixing faults in 4 layer PC boards when they first came out in the mid 70's. The MX300 series two way radios were the first to use them.
My career and lifetime of "adventures" with electricity started when the paper clip met the wall outlet when I was 4 or 5 years old.
These and other experiments scared my little brother senseless. Coincidentally, he is now a research professor and associate dean of the med school at USF. He still does not like electricity.
My other brother got reprimanded several times at USF for his dorm antics, but they usually involved alcohol and fireworks, not electricity. I personally have never been there.
I can hardly recognize the place now it’s grown so much. And I probably won’t get a chance to go back this year, or even to Skycraft. I’m guessing the virus will get worse this winter, and travel there would be ill advised.
Between the Spark-o-Matic, electrolysis machine, harmless-but-painful electric shocker and the home brew 300 watt per channel amps that turned speakers to charcoal without even thinking about overheating, we had a reputation for “playing with power”. We also had some more insidious devices, including a small portable spark-gap transmitter that would take out TV reception in the immediate area. Do anything like that today - especially in school - they’d put you under the jail. I did have the electric shocker back in *middle school* and brought it many times. Took a little more knowledge to make some of the later stuff. A Tesla coil per se was never among them, although I did acquire a big neon sign transformer (doesn’t say Budweiser), a few 10 pound spools of #26 wire, and about 8 feet of 4” PVC pipe reserved for that purpose one day.
Between the Spark-o-Matic, electrolysis machine, harmless-but-painful electric shocker and the home brew 300 watt per channel amps that turned speakers to charcoal without even thinking about overheating, we had a reputation for “playing with power”. We also had some more insidious devices, including a small portable spark-gap transmitter that would take out TV reception in the immediate area. Do anything like that today - especially in school - they’d put you under the jail. I did have the electric shocker back in *middle school* and brought it many times. Took a little more knowledge to make some of the later stuff. A Tesla coil per se was never among them, although I did acquire a big neon sign transformer (doesn’t say Budweiser), a few 10 pound spools of #26 wire, and about 8 feet of 4” PVC pipe reserved for that purpose one day.
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Who was it who had the rotary spark transmitters back in about 1905? Unlike normal spark gap transmitters they could transmit voice. They were used until tubes came along.
I need to look that up.
I need to look that up.
To me, an obvious question is, why didn't the engineers BUY the used set and take it back to test what was
going on? That would give the old folks some cash to get a new set.
Was the town using wifi? It's hard to imagine how the TV could inject interference into whatever cable
might be attached.
G²
No, they were less nasty than other spark-gaps and could be worked to higher power, but were only used for telegraphy.
"spark-gap transmitters could not transmit audio, and instead transmitted information by radiotelegraphy" Spark-gap transmitter - Wikipedia
The rotary spark gap could generate a nearly constant frequency tone modulation due to the spacing between the pins on the spinning disk. The nature of these transmitters tended to create a broadband emission spectrum such that more than one signal could often be heard in a distant receiver. The unique tones made it easier to distinguish the transmitter being heard.
Ah yes, I was confusing Fessenden's rotary spark transmitter with his rotary alternator that could do voice transmission. Different technologies.
Ah.... it seems Canadian Fessenden DID demonstrate voice on spark-gap.
"...words were barely intelligible above the background buzz..."
That's why he hired design of the Alternator.
Amplitude modulation - Wikipedia
"...words were barely intelligible above the background buzz..."
That's why he hired design of the Alternator.
Amplitude modulation - Wikipedia