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Can you build your own TV aerial?

Discussion in 'General Electronics Discussion' started by dietermoreno, May 3, 2013.

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  1. dietermoreno

    dietermoreno

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    Dec 30, 2012
    Can you build your own TV aerial?

    The part of Illinois I live in is the far Northwest Chicago suburbs that is far away from TV transmitters.

    The channels I am listing are the former analog channels that I watched until my parents signed up for Dish Network 8 years ago. I think the new digital channels might use different frequencies now.

    All of the houses in my town that don't have dishes on top seem to have TV aerials on top. The previous owner of my dad's house threw out the aerial and left a Dish but we can't afford Dish (my mom could afford Dish but my parents divorced and my mom moved to Florida).

    Unfortunately it seems like a TV aerial is even more expensive than Dish, so we just didn't watch TV at all for a few months while living in that house and when there was a Bears game we either huddled around the radio like it was the 1940s or went to some one else's house to watch the game, until we bought a streaming player, but unfortunately the streaming player doesn't have the licensing to stream Bears games, so still hudling around the radio like its the 1940s or going to someone else's house to watch the game.

    It really would be nice to watch the game in our own home, but an aerial is too expensive (for the size aerial needed for McHenry County, IL to receive stations from the Chicago loop it runs around $200 at Radio Shack).

    If I can make a home made FM aerial out of random junk, can I build a TV aerial?

    I have seen amplified aerial antennas sold at Radio Shack that are smaller, more affordable, and don't need professional installation on top of the roof, but these are still some what expensive at around $80 for questionable performance.

    Is this amplified antenna not simply RF gain stage transistors that can handle VHF?

    FM clock radios have RF gain stage transistors that can handle VHF too -- for $5 instead of $80.

    Would it work if I connected my home made FM aerial to an FM clock radio with the RF gain stage transistors disconnected from the detector? Would that boost the VHF TV signal enough for TV reception on the VHF band?
     
    Last edited: May 3, 2013
  2. BobK

    BobK

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    Jan 5, 2010
  3. dietermoreno

    dietermoreno

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    Dec 30, 2012
    That coat hanger dipole antenna looks like a good idea for my home made FM dipole aerial too since more metal in contact with the air is probably better than speaker wire in the air since coat hanger is a thicker gauge of wire than speaker wire.

    So essentially an FM dipole aerial and an VHF TV dipole aerial is the same thing.

    Thanks for the advice!

    No more paying Radio Shack hundreds of dollars for an aerial and no more paying for Dish!




    I just have to wrap the coat hanger in duct tape so that when it rains it doesn't short to ground. I would be mounting the coat hanger split in 2 on top of a ski pole which the ski pole is tied to my 2nd floor balcony and the ski pole allows the antenna to pivot to turn it to face perpendicular to the desired station for best reception. So to test it out before buying coax feedline to run from the balcony to the TV in the living room, I can buy a 10 inch CRT analog TV for $10 from the second hand store that no one wants anymore and connect it to a digital tuner ($10 at Walmart) and connect the digital tuner to the aerial.




    Back in the days of analog TV I wonder if anyone attempted to connect a VHF crystal set with VHF aerial to a CRT computer monitor (while the computer monitor is plugged into mains of course) to attempt to receive TV pictures in the static of the computer monitor.

    That would be kind of funny if someone built a "crystal TV".
     
    Last edited: May 3, 2013
  4. duke37

    duke37

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    Jan 9, 2011
    We have aerials in the UK, I thought they have antennas in the US.

    Any bit of wire will pick up a signal, even a guitar, but the aim is to get as strong a signal as possible with as little noise as possible. In order to do this you will need a BIG aerial high up above surrounding obstacles and a very low loss cable to take this signal down to the set.

    If the signal is amplified at the aerial with a very low noise amplifier, made for the frequency concerned, then the cable losses will be of less importance. Amplifying the signal at the bottom of the cable will not be of benefit since your amplifier will be no better than that in the TV unless the TV contains valves (tubes).

    The normal TV aerial is the Yagi, this has a series of elements on a boom. The sizes of the elements and their spacing will depend on the frequency of the signal. There are programs available to calculate the dimensions. I would not consider making one myself since they can be bought reasonably cheaply and I would not be happy putting up an overweight aerial which may fall apart in the first gale.
     
  5. dietermoreno

    dietermoreno

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    Dec 30, 2012
    Okay.

    I saw a very low noise VHF/UHF TV amp at Walmart for $10. Then the aerial doesn't have to be as big (and expensive).

    So your saying if I connect the amp at the bottom of the feedline next to the TV in the living room on the first floor it won't do anything (unless the TV uses vacuum tubes, but my TV is solid state).

    So your saying if I have the amp in the room that has the door that opens to the balcony where the coat hanger home made aerial is mounted, then that will work to improve reception with a small aerial in addition to over comming any losses on the feedline running from the second floor to the first floor.




    Indeed in the U.S. all of the old analog TVs had rabbit ears; but it has been my impression that at least in the Chicago area the rabbit ears only have good reception if you can see the sky scraper that has the transmitter on top of it (which the case for several channels it was indeed the huge twin antennae of the Sears Tower). At my old house that had a TV aerial before we switched to Dish, we had a TV in the living room with feedline run to the aerial mounted on top of the garage. We also had a smaller TV with rabbit ears in the Kitchen so that we could watch TV while sitting at the kitchen table eating. The TV in the living room had good reception for channels 2, 7, 11, and 32 and okay reception for channels 5, 9, and 26. The TV in the kitchen had okay reception for channel 2 (WBBM TV really has a strong signal as good as their radio station), channels 7, 11, and 32 were staticy with bars sliding down the screen but still in color, and channels 5, 9, and 26 were in black and white.
     
    Last edited: May 3, 2013
  6. CocaCola

    CocaCola

    3,635
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    Apr 7, 2012
    The digital broadcast are far superior to the old analog broadcast...

    I have lived in the same area of IL my entire life, and I can say with certainty even with an external analog antenna getting good receptions was a PAIN, constant fine tuning with a rotor or dealing with fuzz...

    Nowadays I use the Internet or my local media library for all my TV needs, but just for kicks last year I picked up this CHEAP digital antenna... It's actually for vehicle use but for under $3 delivered I figured what the heck... I also picked up an adapter to normal coax for ease of install... As I said over the air is not a priority for me (except for American Football as I like to watch it live) Anyway, I took this little 6" tall antenna, hooked up a length of coaxial cable and literally stuck it to the bottom of my houses gutter (they are steel gutters so the magnet stuck)... Basically the antenna was hanging upside down about 8 feet off the ground outside a window...

    So I do a channel scan and much to my surprise I'm getting 58 (just counted them) over the air channels without issue from not only Chicago but Milwaukee and I believe Rockford as well... I was lucky to get five solid broadcast channels back in the analog days without fiddling around...

    The point I'm trying to get across is I doubt you need a large aerial like those from the analog TV days, you might be surprised at what a small new digital antenna does on the cheap...

    BTW back in the analog days (young teen) I made an aluminum foil antenna that was outlined in a magazine, I mounted it in my attic that surprisingly that worked quite well...
     
  7. CocaCola

    CocaCola

    3,635
    5
    Apr 7, 2012
    BTW I just noted this quote from *steve* in dietermoreno's signature...

    Does foil chewing gum wrapper count? :) For some odd reason EVERY time I rent a car the accessory fuse is blown not allowing me to use my GPS or charge my phone... Leaving me to "fix" the fuse with what I have on hand... :)
     
  8. davenn

    davenn Moderator

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    Sep 5, 2009
    sorta the length of the antenna varies with channel freq .A diople cut for the 88-108 MHz FM broadcast band will give OK reception but wont be the best

    No, a dipole ISNT going to perform like a hi gain multi element/band yagi
    specially if you are some distance from the transmitter

    And DEFINATELY NO a dipole antenna is never going to replace a dish antenna for satellite reception


    NO, bad reasoning .... if the antenna is just a dipole instead of say a yagi then you are not going to have as much signal gain, meaning the signal is going to be noisier. That means the amplifier will just amplify that noisy signal to a larger noiser signal NOT a signal with less noise !!!

    Dave
     
  9. davenn

    davenn Moderator

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    Sep 5, 2009

    LOL maybe .... wouldnt be the first time I have done that in the car or on a transceiver radio in the car when out on a hilltop somewhere ham radio contesting

    But I wouldnt do it on gear at home, where fuses are readily available

    Dave
     
  10. dietermoreno

    dietermoreno

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    0
    Dec 30, 2012

    Oh, so if your getting all of those digital stations at your house in Gurnee with a 6 inch antenna hanging down 8 feet off the ground, certainly a home made dipole aerial mounted 10 feet above the ground on top of a 4 foot tall ski pole should receive in digital with no problems, compared to back in the analog days when I was in elementary school you needed a huge Yagi mounted on your roof to get acceptable reception on more than about 4 channels. I already told you earlier in the thread that I live in McHenry County. Actually I mean Island Lake, IL on the east of the border in Lake County, but only 2 blocks away from McHenry County, and in terms of TV reception a 1000KW TV transmitter on top of the Sears Tower doesn't know the difference between 2 blocks and 5 miles



    Makes sense. Crap in = crap out. Staticy in = louder staticy out. So I guess those TV amplifiers are mostly only good for people who already either live close to the transmitters or have a yagi, so it won't help me because of where I live and I don't have a yagi.
     
    Last edited: May 4, 2013
  11. duke37

    duke37

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    Jan 9, 2011
    Putting an amplifier just before the setis unlikely to help unless the set is poor. Adding any amplifier or bad component will increase the noise. You are after a high signal to noise ratio, increasing signal and noise by the same amount will not help.

    An amplifier can help if placed close to the aerial to compensate for cable attenuation. It will also help if the signal is to be split for more than one TV, it must be before the splitter.

    In the UK we can get maps of signal strength from TV transmitters. In the area where I live there are many hills and valleys and it is possible to get a program to plot the land profile from the transmitter. I am lucky that I can just see the tip of the mast of the local low power TV repeater but this only transmits the most popular programs. I cannot receive the main transmitters as the hills and a big house above me are in the way. I also have a dish and watch the subscription free channels, alternatively, I do somethig useful.

    A decent yagi in the UK will cost £30 to £40, say $50. Good cable is a must and will cost quite a bit, it must be weather proofed so that no water enters the cable end.
     
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