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Discussion Starter #1
First let me thank everyone that posted information here at digital home for me to learn how to get free OTA from my apartment.

Living in an apartment makes it somewhat impractical to use an outdoor antenna to pick up OTA channels. However the advantage of having height has it's advantages. For example, I'm in a 15th floor apartment, so that's like a house having a 130ft mast to mount an antenna. I hope this guide, plus the simple antenna plans is useful for my fellow apartment dwellers wanting to get some free OTA TV.

This is a simple guide. Better antennas will produce better results. But this simple guide should get you started and get good results.

Height

Height is important. If your apartment is on the ground floor then you really don't have an advantage. The higher you are up the better and you'll be able to pick up signals from far away. Also keep in mind ground terrain, if you are in a valley then your height won't be as high if your apartment building is on a hill. I'll post two scenario - one from the 15th floor and one from another location on the 2nd floor.

Are you facing the TV transmitters?

Use tvfool.com to locate where the tv station transmitters are located. tvfool will display a directional chart showing which direction and how strong the signal is. Compare the directions with the orientation of your apartment building to see if you are facing the tv transmitters. Use Google maps to help with orientation, the Google maps and tvfool.com align North to the top of the page. If you are not facing the transmitters, unless you are really close you'll not receive them.


A tv fool chart showing the direction, distance and strength of the stations. Stations marked LOS (line of sight) and 1 Edge you should be able to receive. 2 Edge are weak and might not come in. Tropo stations you will not receive.


This is my building in relation to tv transmitters. My window faces the Toronto tv stations, but the buffalo stations will be blocked. I will not get the stations to the south or west as they are on the other side of my apartment unit.

Look out the window

Clear and unobstructed view? That's perfect for OTA. If you have large buildings in front of you, that's not good. A mountain - that's not good. You need line of sight for best tv reception.


A great view that an antenna really likes
 

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Making a simple bi-quad antenna

You'll need some simple tools. Pliers, screwdriver, ruler, wire strippers and an electric drill. You'll need some materials. Household electrical wire, a 300 ohm to 75 ohm balun, and 75 ohm coax cable.

You can use either 12 gauge copper wire or aluminum grounding wire that is available from any retailer that sells outdoor antenna installation equipment/supplies.


All you need to get started

The bi-quad antenna

The biquad antenna is two diamond squares measuring 17cm on one side. The diamonds on one on top of another with the balun connecting at the center of the antenna. There is no reflector to this antenna. This antenna provides moderate gain and has quite a wide angle for reception so it doesn't have to be point exactly at the tv transmitter for it to work.


A biquad antenna mounted to a scrap piece of wood

Cut, straighten and measure wire

You'll need about 5ft of wire. Clamp one end in a pair of vice grips and put the other end in the chuck of your drill. Have your significant other hold and pull the vice grips while you pull and spin the drill. I use a slow speed. As the wire is pulled and spun it will become super straight.

Each side is 17cm and there are 8 sides to this antenna. So measure 8 sections with your ruler 17cm for each section. Trim excess wire.

Bend 90 degrees at a time to make the diamonds

If you have a tile floor it makes it real easy to bend each bend 90 degrees. I use two pliers to make the bends easily. You'll want the ends of the wire to be in the center of the antenna. You'll be connecting the balun here with screws so no soldering is required to join the ends together.


A few simple 90 degree bends and the antenna is done
 

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Discussion Starter #3
Mounting the antenna

The antenna needs to be in your window. Not several feet away, even a few feet away and you'll lose reception on some of the channels. There are probably lots of ways you could mount this antenna in your window, I'll show you two. Depending on how you mount the antenna will decide which balun to use.

In the previous picture above I have one antenna mounted on a scrap piece of wood with some wood screws. I used a balun with wire leads and screw terminals to attach the antenna, balun and wood together.

Another antenna I mounted the antenna with an adjustable fixture that was mounted to the wall beside the window.



I used a leadless balun and F-connector adapter to connect the coax cable to the balun.



Using this method you'll need to take apart the balun and trim some of the plastic so the antenna can be screwed to it. First trim the sides where the screws are:

 

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Discussion Starter #4
And then trim the tabs that snap the two halves of the balun together:



You'll know how much to trim and what to trim when you try to attach the antenna to the balun:



Use the F-connector adapter to attach the coax to the balun and afix it to your mounting bracket. I just used black electrical tape.



This type of mount is now done! Connect the other end of the coax to your TV and enjoy OTA.
 

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Reception results case #1

Using the antenna as shown from the location in the above tvfool chart on the 15th floor I'm able to pick up these digital channels-

5.1, 9.1, 11.1, 17.1, 23.1, 25.1, 36.1, 41.1, 57.1, 66.1

I am unable to pick up stronger channels 26.1, 4.1 because the apartment doesn't face buffalo and the building blocks it. Another channel 44.1 comes in, but it breaks up. The direction is the same but the transmitter is not on the CN tower but on a building that is not as tall.

Reception results case #2

This location is in Hamilton (on top of the mountain) and is on the second floor. The view faces Buffalo - east. Although it is not as high the previsous case, the terrain is relatively unobstructed to the tv transmitters in Buffalo.


Another great view for an Antenna. This time on the second floor

Here is the tvfool chart for this location-



Channels I can receive from this location -

2.1, 4.1, 5.1, 7.1, 11.1, 15.1, 17.1, 23.1, 26.1, 36.1

Again there are stronger signals, but because of the orientation I can only receive the channels that the apartment is facing directly.

Improving these results

The simple biquad antenna works very well, however you can get better reception with a few tweaks. First adding an amp will improve some of the weaker channels. I use a GE amp I bought at Canadian Tire to get the two weaker omni channels (44.1 and 64.1).

You can build a double bi-quad which is 4 diamonds. You'll get more gain at the cost of directionality. In other words when the channels are weak because of weather I'll swap out the double bi-quad but I'll have to aim it more closely at the tv transmitters.


A double bi-quad. Notice the electrical tape where the wires cross at the top and bottom diamonds

That's it, good luck and have fun!
 

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They used to come with VCRs and RF game consoles. You might find them in big box stores and dollar stores. They are push on, and you need an F-81 to couple them to coax.
 

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Where did you find them? I was looking for something that small without leads, but I ended up having to use a CM balun and cramming it into a small space.
They are very common indoor baluns, available at Radio Shack and Walmart, to name a few common places.
 

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K-Mart has a package deal, you get the one shown that connects to the back of digital converter and you use 300ohm twin lead line to connect to the antenna and it comes with a round 300ohm to 75ohm one that you connect your coax cable to one end and it has a small length of the 300ohm twin lead wire coming out the other end of the round adapter/balun to connect to the antenna. Much cheaper than Wal-Wart and Rat Shack at only $2.99. :p

73s
 

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Wal-Mart in Canada had the same package deal of 2 Philips matching transformers (1 of each type) the last time I checked.
 

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cheap matching transformers

In Canada try princess auto , the same thing is selling for $0.99 . Your local princess auto may have these. They are philips brand.
 

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Improving these results

The simple biquad antenna works very well, however you can get better reception with a few tweaks. First adding an amp will improve some of the weaker channels. I use a GE amp I bought at Canadian Tire to get the two weaker omni channels (44.1 and 64.1).

You can build a double bi-quad which is 4 diamonds. You'll get more gain at the cost of directionality. In other words when the channels are weak because of weather I'll swap out the double bi-quad but I'll have to aim it more closely at the tv transmitters.
Hi

I also saw that amplifier (20$?) at Canadian Tire. I would think it is a distribution amplifier and not a pre-amp since it cannot be mounted very close to the antenna (when it is installed outside, which may not be your case). In any ways, did you get both weaker channels (44.1 and 64.1) because of the amplifier, because of the double-biquad or do you need both to get those 2 channels?

Thanks,

jf
 

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Discussion Starter #18
It is a distribution amplifier. However it does work well as a pre-amp as well for the digital channels. I experimented with this amp and found that if it was connected to the antenna - physically that is - it didn't perform as well as having a small 3ft coax cable connecting the antenna to the amp. My first thoughts were to mount the antenna on the amp the shorter the distance the better, but it didn't work better but possibly worse.

Hope this makes sense.

I pull out the double biquad when weather conditions cause poor performance across the board on all channels including my strongest - channel 5.1.
 

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Wonder what the noise figure is on that amp? Anyone know?
Don't know. But if I add the amp I can receive more channels. Both during normal reception and tropo. Tonight seems to be a tropo night so I can get a few more channels such as 26.1 and 51.1. Without the amp I can't.

So I'm assuming the noise has to be less than the amplification, if the amp consistently works better than without.

Hope this makes sense.

Someday I'll get a good quality preamp to compare with this simple amp.

I bought this amp because it was $20 and Canadian Tire has a good return policy so if it didn't work for me, I would just return it. So far it's working for me. I would recommend it, cause if you don't mind returning it if it doesn't work for you all you did was spend a little time checking it out.


Edit: Just an aside, tonight is a great tropo night. I'm picking up 2.1, 4.1, 7.1, 16.7 (wierd some digital radio channel????), 21.1, 29.1, 49.1 as well. So if this means anything I can pick these up with the amp better than without.
 
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