The pain of TV's and Cable

[GAD]

Can you 3D print one?

It'll be 18 inches tall, but absolutely.

 

[Aristera]

It'll be 18 inches tall, but absolutely.

I could use my brother's ham radio tower at the house where I'd like to cut the cable. He's worried about proper grounding. 70' three piece retractable.

 

[Charlie Bernstein]

I could use my brother's ham radio tower at the house where I'd like to cut the cable. He's worried about proper grounding. 70' three piece retractable.

Priorities!

 

[GAD]

I could use my brother's ham radio tower at the house where I'd like to cut the cable. He's worried about proper grounding. 70' three piece retractable.

All hams are worried about ground. Everyone should be, but hams actually are because we tend to build/install/play with really efficient and attractive lightning rods like that one.

 

[Aristera]

All hams are worried about ground. Everyone should be, but hams actually are because we tend to build/install/play with really efficient and attractive lightning rods like that one.

You should see the copper cables and rods. Good thing that it retracts. He's very good at finding sources of interference. Uses a parabolic device that can pin point direction. In rural areas Spectrum uses signal amplifiers that often leak. Spectrum has been very responsive. I think the FCC gives them a short timeline to correct. BTW the concrete base on that antenna is 6'x6'x8' deep with an embedded internal cage structure. Gets pretty windy 5 miles in on the Lake Erie ridge.

 

[Midnight Toker]

You should see the copper cables and rods. Good thing that it retracts. He's very good at finding sources of interference. Uses a parabolic device that can pin point direction. In rural areas Spectrum uses signal amplifiers that often leak. Spectrum has been very responsive. I think the FCC gives them a short timeline to correct. BTW the concrete base on that antenna is 6'x6'x8' deep with an embedded internal cage structure. Gets pretty windy 5 miles in on the Lake Erie ridge.

Just did the math on that concrete block. (I work for a concrete/asphalt company owner) I’d bet the steel gives way before that block ever budged. That’s a 43,000 lb block he has in the ground!!! Not even a large excavator could move that thing!!

 

[Charlie Bernstein]

Oops. Post deleted for too much information. Sorry, mods! My culpa. I'll try again:

Silverfox, you got me way beat. Didn't have a TV till my wife moved in with a small one seventeen years ago. We've since upgraded to a much bigger one, I think about 30". Seems huge to me. Plenty big enough for our purposes, anyhow. We don't need to count nostril hairs.

Never had cable or a dish, we haven't tried subscribing to any streaming services, and we only get one broadcast channel here in the sticks, a news station we hate and will never watch. So we just use the TV to watch DVDs. We're mourning the passing of Netflix DVDs, of course, but we're lucky to live in Maine, where the interlibrary system has more DVDs than Netflix did.

When we want news, we have the internet. And print and radio, of course. And we've started going to the movies again. Happy days!

So you win at a walk on the plugged-in front. Happy viewing!

 

[Opsimath]

Just wondering, does a ham radio tower pull in a TV signal?

 

[GAD]

Just wondering, does a ham radio tower pull in a TV signal?

The tower is just there to hold the antenna(s). Antennas are (mostly) tuned to frequencies, so if you put a TV antenna on the tower then it would get fabulous reception.

The reason for the tower is that the curvature if the Earth limits certain types of signals as do things like buildings, so the tower is really just for making the antenna higher and to impress radio nerds. it can also be safer since the big guys can send a lot of power while transmitting and you can actually get RF burns if you get too close.

 

[chazmo]

Gotta' impress your neighbors (or bring out the pitchforks)!

 

[Opsimath]

RF burns? Radio frequency?

Does being too close to the antenna cause it? What hapoens if you get one? Can you tell it's happening?

 

[chazmo]

You really don't want to know, Cynthia.

 

[Opsimath]

You really don't want to know, Cynthia.

Oh, dear!

 

[GAD]

RF burns? Radio frequency?

Does being too close to the antenna cause it? What hapoens if you get one? Can you tell it's happening?

Yes - usually happens when touching a ham radio antenna but again it depends on the power going into it. As with all energy emissions the energy dissipates with the inverse square of the distance. This is called the Inverse Square Law and it means means if you start at 1x (let's say a foot) distance then double that you cut the energy to 1/4th. Two feet = 1/4, three feet = 1/9, four feet = 1/12, etc. This is true for all energy emissions and is why if you go outside on a sunny day the unfathomably large nuclear furnace in the sky feels nice and warm on your skin. Note that exposure duration matters as does the energy wavelength which is why you will eventually get a sunburn. This pic generally helps to understand why:

 

[Prince of Darkness]

Just think microwave oven!

"In 1945, the American engineer, Percy Spencer was carrying out maintenance work on a live radar set. Whilst working within close proximity to the radar equipment, he felt a tingling sensation throughout his body and noticed that a chocolate bar in his pocket had completely melted. After some investigation he determined that it was the microwaves being emitted by the magnetron tube in the radar set which had caused the chocolate to get warm enough to melt."

I don't know if it's true, but I did hear a story that they were finding a lot of dead birds near the first British RADAR stations, early in WWII. On examination, they were finding that their internals were cooked!

I have friends who were formerly in the RAF and they have said that there were no go areas around the operating RADAR stations due to dangerously high RF radiation levels.

 

[GAD]

Just think microwave oven!

"In 1945, the American engineer, Percy Spencer was carrying out maintenance work on a live radar set. Whilst working within close proximity to the radar equipment, he felt a tingling sensation throughout his body and noticed that a chocolate bar in his pocket had completely melted. After some investigation he determined that it was the microwaves being emitted by the magnetron tube in the radar set which had caused the chocolate to get warm enough to melt."

I don't know if it's true, but I did hear a story that they were finding a lot of dead birds near the first British RADAR stations, early in WWII. On examination, they were finding that their internals were cooked!

I have friends who were formerly in the RAF and they have said that there were no go areas around the operating RADAR stations due to dangerously high RF radiation levels.

One of my high school friends was a radar tech in the navy and he always talked about dead birds near the dish.

As a tangental story, I used to work on mainframes and all the terminals were serial which meant a 4-wire cable run from wherever the terminal was to the mainframe. One of our clients was the US Navy in Honolulu and they were reporting seemingly random system crashes. It got so bad that we sent a guy out to "babysit" the machine which meant he sat there all night to see if he noticed anything weird.

As he watched one of the ships came in to dock the system crashed. We determined that the spinning radar dish was the cause since the mainframe was on a floor just about at the same height as the dish. On these old mainframes if you unplugged a terminal and left the serial cable on the desk, the unterminated cable acted like an antenna and any signal significantly above the noise floor would be sent right into the mainframe's serial port, This was decades before things like ECC memory so the voltage spike would scramble memory and the system would crash.

I personally noticed this same effect when I was the guy sent out to babysit a system. At 2AM the cop on duty took his break in the parking lot of the business. When he keyed up his mic to call in the system crashed. Same deal: unterminated serial cable.

 

[Midnight Toker]

^ My oldest brother was a radar tech on Air Force c-130's. There's one system in the nose and one the tail...and during ground power testing, if in the wrong place at the wrong time, can really jack you up! Luckily, most of their testing/calibrating was done in air.