Update on combining 2 antenna's ( OTA )

[John Perry]

       Hi forum members
  I came out with great success when I combined 2 antennas, as did Hyper,
the administrator, and others on this site.
      Let me explain so all others here, know where I am coming from.


   Here in Chesterfield Twp, which is located in southeastern Michigan I was
able to pick up all of the TV stations in the Detroit metropolitan area. There is
40 of them as the crow flies, and  I am about 28 miles away. I have, since last year
when I installed the HDBX91 Xtreme Series HD Antenna from "Solid Signal" had great
success except for one channel which I desired to receive from Windsor, Ontario. Canada,
which for some reason, could not be picked up, even though the distance is the same.
      Here is what I found out. Apparently, all of the American TV channels in our area moved from
VHF to the UHF spectrum while still keeping their low numbers on the dial. i.e. 2,4, and 7 which is Fox, NBC,  and ABC.
Windsor's channel, " CBET " channel 9  stayed in the VHF realm at 189 MHz, not allowing me to pick it up with
Solid Signal's antenna. So what I did was to build an antenna cut to the channel 9 center frequency and mounted
it on the mast below the HDBX91 antenna pointed toward Windsor. I used the " Winegard Signal Coupler " CC-7870
so as to input 2 antenna's to the device, with the single output to the TV. It worked so good that I do not need
a pre-amplifier mounted on the mast. Just guessing at where to point it, I am picking up a signal from Windsor
between 55% and 60% strength. I will take a portable TV up on the roof, to zero in on the maximum signal
attainable, when I get caught up on my other work at the house.
        The antenna which I built, is a Yagi with 7 elements which I found on the net someplace, which since that time, I
lost their webb address.  I made it 64" long using 1" square aluminum tubing, and 1/4' aluminum rods cut to length.
The reflector and directors are all grounded to the boom electrically, although according to the experts, they can be
isolated from the boom if desired. Their reasoning is because at the boom attaching point, it is a neutral zone. The
RF waves only contact the outer ends of the reflector, and the director. The driven element, the dipole with the
balun attached, must be isolated from the boom. Because of added lightning protection, I prefer grounding the
parasitic elements to the boom, and mast.
      Since I built this antenna, I discovered a great place for antenna design. For those interested. Go to:

       http:www//.k7mem.com/Electronic_Notebook/antennas/yagi_vhf_help.html

 On this site written by: Martin E. Meserve he has the program installed so anyone can put in the size of antenna
they want, what center frequency they will use to get the channel desired, and it automatically tells what is needed
in regards to element length, and proper spacing.  I think that you will enjoy this site.

     John

[joeroscoe1957]

Thanks John , a lot of detailed info k7mem site . The Yagi looks like it could be a challenge to build ? Just wondering before I try a project as that , does it pick up UHF as well the High-VHF digital channels ? I'm having troubles getting the 5 VHF and the 6 UHF (just to my west) channels in together , on one antenna . Appreciate the info , Joe from Mid-Mo

[John Perry]

          Joe
  Thanks for the interest in my project. When I had this antenna on the ground testing it out, I
was receiving most of the UHF channels in my location, in addition to channel 9 at 189 MHz, which
this antenna was cut for. All of our stations that are around here are about 28 miles distant. All of
the major networks here moved from VHF to UHF. So I do not know if this antenna will pick up the
other VHF stations that you are interested in.
       As was mentioned in my previous post, the antenna that I built was from a different site on
the webb, so the plan was different from the ones given by k7mems site.

    I am not good enough at placing pictures on the forum, but I will put the specifications I used
for the Yagi  below.


     This is a 7 element  Yagi antenna with a folded dipole that is 28.50 inches long, which is isolated
from the boom. The reflector is cut at 31.35 inches, and the 5 directors are cut at 27.00 inches. Electrically connected.
    The spacing is as follows: From the reflector to the dipole it is 11.70 inches. From the reflector to
director #1 it is 16.40 inches. From the reflector to director # 2  it is 21.60 inches. From the reflector
to director # 3 it is 26.90 inches. From the reflector to director #4 it is 38.60 inches. From the reflector
to director # 5 it is 61.30 inches.  With this layout it picks up many other stations. Because k7mems site is probably
much more accurate, you may experience a different outcome. Maybe even better than what I achieved.
    It was great fun doing this project, so I will be doing other Canadian single cut channels in the future. Because
they are 10 miles  farther out, I will use 10 elements instead of 7, and want to try out k7mems calculations.

     Because my first one worked great without a pre-amplifier, I will try the same with the other channels that are
farther out using the 10 element Yagi.       Good luck with yours

       John---Chesterfield Twp, Michigan

[joeroscoe1957]

Thanks for the detailed info , John . I've copied a couple pictures of Yagi antennas , a few years ago when I was building a stacked 16 bay bowtie . Still got the pictures in a folder with my other antenna diagrams . One is very simular to what you described . Don't know when I'll get around to attempting one . But very interested in trying .

[John Perry]

      Hi forum members.
I am practicing how to add photos to a topic. Please bear with me on this.
These photos show the antenna that I recently made out of aluminum, so that
I can pick up channel 9 out of Windsor, Ontario. If it doesn't work, I will get
hold of my oldest son to help me with this. This antenna is center cut for 189MHz.
          John---Chesterfield Twp, Michigan

[cpsp0]

John, we can see you tried, there is a "broken," thumbnail of a pic in your post, but use the "Additional Options," tab under the box you type in and then select the photo from your computer and hit the upload button. THEN WAIT. It takes a little while, but when it's done your photo will be in your post.
So please try reloading that pic again.

 

[John Perry]

       CPSPO

  Here we go again.

   

[John Perry]

         CPSPO

     Thank you for your help in this. Between you and my wife Inge,
the photo's are there. Computers are not one of my many talents.

  John

[cpsp0]

You do nice work, John Perry!

 ::th_clap ::th_clap ::th_clap

[armadillo_115]

Antenna looks good. 

Is that Santa Claus trying to get out of your chimney? lol

[El_Viejo]

That is quiet a yagi array!  What channel is it for?  E_V

[RCC]

Looks like an experienced Ham Operator up on that roof.

Excellent job on the build and install.

[Hyper]

Nice antenna John Perry !

And glad you figured out how to post pics! We love to see pics of folks installs here.

This is the pictures for this antenna you talked about here correct?:

http://legalfreetoair.com/index.php?topic=41792.msg149537#msg149537

And also here:

http://legalfreetoair.com/index.php?topic=41792.msg149826#msg149826


 

[Hyper]

Pictures of the antenna John Perry built here:


http://legalfreetoair.com/index.php?topic=42256.0



 

[danristheman]

In the second pic he looks like he is shooting a bow and arrow. Just picking on the new guy a little bit.