How to make a powered amplifier for over the air tv?

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DTV dishes operate at a shorter wavelength so a larger dish may be necessary.

What signal levels does this report for your location
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http://www.tvfool.com/?option=com_wrapper&Itemid=29 Just enter your zip code and antenna height ( guess) and paste results
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These are very popular here but not same as mine.
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The results are **broken link removed**
I have a dish network dish antenna that i am using that is a little over 24" , I was going to change it eventually to a bigger dish of 40" or more, i was also thinking of getting Free to air satellite as well, I will be using the 24" one until i can get a bigger one, I was going to get a dish like this This dish can get over the air antenna and free to air satellite signals
 

looks like 7,8,10 are VHF so a Yagi works best for those wavelengths.

21 is in the lower region of UHF

so a Yagi works best for those wavelengths.

for Ch 10. full wave @ 200MHz is 1.5m so half wave Yagi elements that work best are near 30", shorter for Ch21

A bigger ridged dish would be better too.
https://www.antenna-theory.com/antennas/travelling/yagi3.php
 
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SunnySkyguy said:
looks like 7,8,10 are VHF so a Yagi works best for those wavelengths.

21 is in the lower region of UHF

so a Yagi works best for those wavelengths.
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Will i be able to still that dish that i posted in the other picture of the dual over the air and free to air satellite ? I will still get those VHF signals?
 

Brian's rule of thumb: to be useful, the dish diameter should be at least 10 times the wavelength of the signal you want to receive.
So for 700MHz the wavelength is 321mm and the dish should be > 3.2m (about 10.5')

For lower frequencies it needs to be bigger. Below about 1000MHz it is easier to use Yagi antennas to get equivalent gain.

The dish in the picture is a combination of dish/LNB for satellite reception and something in the disk on the double arm for VHF/UHF. Its gain on normal TV channels will be very small (it is probably nothing more than a loop) and the dish will have absolutely no effect on reception.

Brian.
 

SunnySkyguy said:
VHF gain drops off quickly moving from 1/2 to 1/4 wave dish due to impedance rise
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So basically the signal gets reduced to 1/4 what it was , and also makes gain 1/4 of the gain because of the signal?

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So what you are saying i would need one of those c-band dishes, which are the dishes that where used in the 80's?
 

Michael Weaser said:
So basically the signal gets reduced to 1/4 what it was , and also makes gain 1/4 of the gain because of the signal
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unfortunately not, 1/4 wave has the property of impedance inversion so it would become a null if 1/4 wave

rule of thumb is you need 15 elements to get near 15 dB gain which is about the limit for Yagi's. and -about 30" elements wide. extra ones a lot shorter and longer won't help.

You need about 3-8Mbps for Ethernet on KODI possibly less on SD.
 
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I have seen youtube videos saying that with a antenna and a old satellite dish, they have said i've gotten 20 more channels ...... and they talk about i get all the channels vhf, uhf , and stations from other states , and other parts of the state , which of what you are saying , I would call bullshit , I have seen people use yagi antenna in 2 ways I have seen youtube videos saying that with a antenna and a old satellite dish, they have said i've gotten 20 more channels ...... and they talk about i get all the channels vhf, uhf , and stations from other states , and other parts of the state , which of what you are saying , I would call bullshit.
I have seen people use yagi antenna in 2 ways that way , and the same way that an lnb is mounted having it pointed inwards.
 

One can get 30 channels on a good day here but this is a major city 16 on a bad day and only a few are any good. Internet TV is the way to go. free with KODI
 

So what you are saying i would need one of those c-band dishes, which are the dishes that where used in the 80's?
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Look at it this way: the dish has to be bigger for the same gain as the frequency reduces. Those huge dishes were for 'C' band broadcasts at around 4,000MHz, you want one to work at less than 700MHz! Before even considering it as an option, remember that satellites sending TV to your area are in orbit and the dish points to the sky. For terrestrial signals, you have to point it to the horizon which is even more difficult.

I would say that almost all commercial antennas are designed by artists, not engineers. They try to make something that looks technical because people will buy it. The truth is that if they used a short length of wire instead of the fancy metalwork, it would probably work just as well.

For a dish to work properly, the capture area (area inside the circumference of the dish) has to be focussed on one point and the receiving dipole has to be at that point. There is absolutley no advantage to additional directors when the signal is aimed away from them by the dish. What you are seeing in the picture is a dish being used as the reflector in a Yagi configuration. It does exactly the same as the slightly longer element at the back of a conventional 'flat' Yagi except that by being above the center line of the boom, its effect is reduced and the antenna sqints downward toward the ground.

Brian.
 


You where saying that i would need a dish that would be 10x the size of the wavelength . or about 3.2 meters or 10.5 feet, they make satellite dishes that are around that size and say to be C-band signal compatible , much smaller than the original C-Band dishes. they even make C-band dishes that are 6' or smaller, well they say they work for c-band.
 


You where saying that i would need a dish that would be 10x the size of the wavelength
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...as a minimum size to be of an use. Ideally, it would be twice that diameter or more and at lower frequencies it would have to be much bigger. For the lowest US TV channel (ch2) at 54MHz, the dish would have to be 41m diameter (about 135').

In the picture, the dish is not being used to focus the TV signal, it is just a reflector behind the dipole. A simple straight metal rod would work just as well, but then it wouldn't look as technical and people wouldn't pay as much for it!

As Tony suggests, all you need is a decent quality Yagi and a cheap amplifier. Do be aware though, that an amplifier makes all the background noise bigger as well as the signal you want. For digital broadcasts, signal quality is more important than signal strength and no amplifier will correct the distortion introduced by the path between the station and your TV. A strong distorted signal is no better than a weak distorted signal.

Brian.
 


I heartily agree with the basic observation...
 


I do not have one of those adaptors that are you are talking about. I am using a standard dish network 500 dish, which is between 20 - 26 inches , I will be using that until i can get a bigger Dish or a better antenna. I Was actually thinking of using a channelmaster amplifier , I wasn't going to get the amplifier that you where showing me, i was going to get the titan 2 one , which you can pick from medium or high gain, or i was going to get the newest one which is called amplify, in which you can select between medium and high gain. The Antenna length is going to be at least 50 feet long, i might be able to get it be less.
 

SunnySkyguy said:
do you get any signal?
coax loss?
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With using a dish i do get channels , I used the dish and a small antenna , one of these **broken link removed** , If i don't have the dish I get nothing, if i have the dish and have the little antenna pointed into the dish , i get a few channels. I have the little antenna pointed in like a Lnb.
 

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