Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

How I made an HDTV antenna so I could watch Jeopardy last night

blamcast.net

Post reply on HN
Print view View original

11–20 of 74 posts

Re: How I made an HDTV antenna so I could watch Jeopardy last night

#11

Post by chaosmachine »

Swizec wrote: post #4

Thanks, I'm glad you took our comments to heart :) Two questions: 1. What exactly is the purpose of the cardboard tube? I'm guessing the key point is that it's non-conductive, but would the same coil work without the cardboard? (not very knowledgable about antennae I admit) 2. How the hell does that connector even work? It looks so marvelously out of place ... does this mean the wire mesh around the normal coaxial ca…

1. Basically, I just wanted something I could wind a length of wire around and stick in my window. The tube did the trick. After the show, I tried a few other things, like wrapping the tube with tinfoil, but the basic wire around the tube design performed best.

2. The shielding is there to keep signal interference out, which is useful if you have a clean source to start with (ie: Cable TV or a properly designed antenna). In my case, I just wanted to pick up as much signal as possible, and this is what I had to work with.

Re: How I made an HDTV antenna so I could watch Jeopardy last night

#12

Post by Retric »

Swizec wrote: post #4

Thanks, I'm glad you took our comments to heart :) Two questions: 1. What exactly is the purpose of the cardboard tube? I'm guessing the key point is that it's non-conductive, but would the same coil work without the cardboard? (not very knowledgable about antennae I admit) 2. How the hell does that connector even work? It looks so marvelously out of place ... does this mean the wire mesh around the normal coaxial ca…

Shielding is useful but not exactly required if the signal is strong enough and the cable is short enough. EX: You can use barbed wire to send 10 baseT. However, 1 gigabit has major issues without shielding.

PS: I once noticed my Sega genesis was producing a vary fuzzy picture, so I went to fiddle with the cable and noticed it was not even plugged in. At the time I really freaked out and to this day I still wish I had a picture.

Re: How I made an HDTV antenna so I could watch Jeopardy last night

#14

Post by icegreentea »

tocomment wrote: post #13

Why doesn't the outside part of the coax port have to also touch the wire?

I don't think coaxs have a 'return' on the actual cable. The outside part of a coax is just a screw for holding the cable in place. It could be made with plastic for all it matters.

Re: How I made an HDTV antenna so I could watch Jeopardy last night

#16

Post by gcheong »

tocomment wrote: post #13

Why doesn't the outside part of the coax port have to also touch the wire?

Because no signal is transmitted on the outside part, that is just used to secure the cable to the port. If you look at a coax cable, you will see it is essentially a copper wire wrapped in shielding wrapped in a vinyl(?) casing and the end is terminated with a connector that feeds the copper into the port and secures the connection.

Re: How I made an HDTV antenna so I could watch Jeopardy last night

#17

Post by ck2 »

minalecs wrote: post #6

Heres plans for an antenna I built. http://www.tvantennaplans.com/ I like the simplicity and potential of your design though. I want to try an array of tubes and wiring, and see how well that works.

Note that 4-bay may be overkill depending on how far out you are.

I can get all the stations possible in my area with just 2-bay.

So build with 2-bay first and test maybe to save time/money.

I also did not need the reflector, in fact it made things worse.

Re: How I made an HDTV antenna so I could watch Jeopardy last night

#18

Post by JonnieCache »

PaulHoule wrote: post #3

I'm in a place that's hilly and the towers are far away. Maybe I'd get something with a 75 foot tower, maybe. For me it's ivi.tv

>Maybe I'd get something with a 75 foot tower

    1) Attach 75-foot wire to TV
    2) Attach other end to weather balloon
    3) Inflate balloon
    4) Watch Jeopardy
Maybe tie some brightly coloured threads onto the wire at intervals to stop birds flying into it.

Note: there are probably many other reasons why you shouldn't do this. Make sure to let us know when you find out what they are.

Re: How I made an HDTV antenna so I could watch Jeopardy last night

#19

Post by barrkel »

JonnieCache wrote: post #18
PaulHoule wrote: post #3

I'm in a place that's hilly and the towers are far away. Maybe I'd get something with a 75 foot tower, maybe. For me it's ivi.tv

>Maybe I'd get something with a 75 foot tower 1) Attach 75-foot wire to TV 2) Attach other end to weather balloon 3) Inflate balloon 4) Watch Jeopardy Maybe tie some brightly coloured threads onto the wire at intervals to stop birds flying into it. Note: there are probably many other reasons why you shouldn't do this. Make sure to let us know when you find out what they are.

Enjoy the pyrotechnics during the next thunderstorm.

Re: How I made an HDTV antenna so I could watch Jeopardy last night

#20

Post by JonnieCache »

Pyrodogg wrote: post #10
Swizec wrote: post #4

Thanks, I'm glad you took our comments to heart :) Two questions: 1. What exactly is the purpose of the cardboard tube? I'm guessing the key point is that it's non-conductive, but would the same coil work without the cardboard? (not very knowledgable about antennae I admit) 2. How the hell does that connector even work? It looks so marvelously out of place ... does this mean the wire mesh around the normal coaxial ca…

1. Structure. The wire he's using isn't strong enough to just stay up standing by itself. It would fold over on itself. Also, it probably does need to be non conductive or you need to use coated wire. 2. It's not shielded because the entire thing is the antenna. I guess he could shield it between the TV and the actual wrapped tube part but this is sow low-tech it wouldn't make a difference. Your standard roof mounted…

>Your standard roof mounted antenna is shielded between the antenna and the tv because you don't want interference between the two points.

To clarify this, with a roof mounted antenna the wire needs shielding because it is typically running down the middle of the house and thus would be subject to interference from the many electronic devices therein.

With this guy's solution, the wire just runs out of his window, and therefore as long as he doesn't have any ageing analogue equipment (speakers, cordless phones etc) near his TV or his window the issue of interference is minimal.

Post reply on HN