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Custom-cut antenna for WVNY-DT 13

Here's a description of the antenna I built for WVNY-DT VHF 13 (210 MHz to 216 MHz)

You will see that instead cutting element for 210 MHz I cut them for 216 MHz.

For the BOOM I use a piece of plastic about 4 feets long.
For the element I use electric (copper) wire (Remove the insulation!).

Step One get a piece of non condutive material of about 2" per 4'
Mark the Boom at about 3 cm that will be the starting position. (To be on the safe side you can use a longer boom and start let's say at 2", that is if you want to add element for lower VHS)



You will then need 5 pieces of wire: 678 mm,633 mm, 629 mm, 606 mm


#1 Mark your position 0 then Stample a wire of 682 mm (Center each wire)
#2 Mark at 278 mm Stample a wire of 678 mm (Put 2 stamples on each side not in the center)
#3 Mark at 381 mm Stample a wire of 633 mm
#4 Mark at 631 mm Stample a wire of 629 mm
#5 Mark at 931 mm Stample a wire of 606 mm

Now cut about 5 mm in the center of #2. (This is where we connect the element)


Connect an antenna wire to #2 (Since I'm not to good with soldier i did stample them and then soldier them.)
Connect the antenna wire to you UHF antenna feed line. (Don't use a 300 to 75 and a combiner in my case this was killing the signal)

that's it.

Once it is connected use aluminum foild to tune it (Making #2 and #1 longer mm per mm) you will most likely also have to play with #2 and #1.
I hope you understand my instruction I'm really not a tech writer.

Have fun.
 

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If you cut it for the middle, 213, you have made it impossible to go past that. Cut for the higher number so that you can access the entire channel band as needed. :)
 

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Lower frequencies are longer wavelength. Should it not then be 210? Maybe that is why Kro is adding foil to fine tune it? I don't know, just askin'.
 

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Lower frequencies are longer wavelength. Should it not then be 210? Maybe that is why Kro is adding foil to fine tune it? I don't know, just askin'.
That's what I did first but chanel 12 and 10 were comming in to hard.
 

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I am no expert on antenna design, but according to http://www.kyes.com/antenna/rabbitear.html 1/2 wave antennas need to be 'slightly less than 1/2 wave length in free space to correct for "end effect" which makes wires appear slightly longer than they actually are.' Could this be a factor in Kro's decision to cut for 216MHz?
 

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Could this be a factor in Kro's decision to cut for 216MHz?
I use 216 MHz because

#1- With 210 MHz I was receiving to much signal for 10 and 12.

#2- I also build a UHF (Kind of CM4228) and it was receiving VHF (which was bugging me). In an attemps to optimize the antenna I cut the element bow tie of 1/4 inch and an unexpected side effect was that I was not getting any VHF with it (Which made me happy).

So before the cut the attena from one end of right bow ties to the other end of the left bow tie was about 26" 1/2 which is the element size for 216 Mhz.

So I deduct that the minimum size to receive VHF is 26" 1/2 and the closer to 90% of a half wave lenght more signal you get...From all VHF channel so the idea is to be has far has possible from 204-210 range and still get the 210-216...(that's where the aliminum foil is usefull)

But then again I'm really not an expert I'm just trying thing and i describe what work's for me.
 

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Hello,

Can you post a picture of the antenna please. With a close-up of the #2 element were you solder the 75 ohm

Thanks.

Ok I post it in Built it your self...

Be patient with it, the signal can go from low to high just by moving sligly the elements...

I was playing with it last night and when I was touching the element the signal was 100% I guess i'm a very good VHF antenna:)
 

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I tried but the Attic is too dark...
I connect TV Lead Wire to the feed line of the UHF anttenna (300 ohm) which is connect to the 300 to 75 ohm transformer.

If you want to simplify your life you could buy Rabbit Ear (2$) and a 300 to 75 ohm transformer (1$) and use this for #2.
 

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Modifying a UHF/VHF 97" boom down to UHF only

Hi all,

A co-worker gave me an old antenna to replace my exsiting ministate. Its missing a few elements on the back end.

my tower is, shall we say, not properly installed, and has a slight tilt to it after I bumped into it with a pick-up. I don't really want to climb back up 20' above the roof line. I was thinking about cutting off the VHF part of the antenna so I can fix the uhf directly to the tower about 6' above the roofliine and pointing it at the CN tower. I thought I'd then test a direct connection to the tv before fiddling with combining the signal with the ministate.

the question:

will cutting off the boom behind the corner reflectors of the UHF adversely affect the signal?
 

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will cutting off the boom behind the corner reflectors of the UHF adversely affect the signal?
I've hacked off a UHF corner-reflector yagi once before and it was fine - the only trouble was that it wasn't the best product in the first place, but it worked. Free is free, so if it doesn't work well you aren't out any bucks. ;) If the connectors are rusted/decomposed just use a hacksaw.
 

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Well, I tried it. I cut the boom (which was one piece, front to back) behind the mast mount and left the front VHF elements attached. I didn't want to climb my tower so I clamped the UHF to the tower at about 25' up (7' above the roof line). I aimed ot at T.O. and got... nothing better then the ministate. I was using a 50' run of rg6. i guess I need to add a pre-amp?
 

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A preamp will definitely improve things for you given the length of cable you're using too. Getting it higher up the tower some day will also really make a difference, if possible.
 

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I find that photo of the home-grown 4-Bay in the attic quite troubling because of all the multipath interference that will happen from the huge amounts of foil duct wrap, let alone any other metal up there! :eek:
 

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I tried the one recommended by dsspredator in post #76.

I have the same results as my 130$ Radio-Shack. I can get CBC, SRC and the 2 PBS. Nothing more, nothing less. The only difference is that this one cost me 0$.
 

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rickleg,

I am not sure which antenna you have from Radio Shack, but it is probably a combo VHF/UHF/FM antenna. Bowtie antennas are UHF antennas and typically won't receive VHF (or FM) very well (the CM4228 is the exception to this rule). Once the analog shutdown is complete, some stations will be moving their digital broadcast to VHF and you will want something to pull them in.
 

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Roger1818,
you are right. I just wanted to see if that handcraft antenna would work and the surprise for me is that it is working as good as my Radio-Shack (which is a fm/VHF/UHF).
My goal is to go with a Channel Master 4228 if I can find a way (or the courage) to mount it on the roof.
 
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