Bill2226 nice experiment. Do keep us informed I have a few questions if you don't mind.

What you you using to combine the antenna signals ?

Did you ever test a single 4228 antenna performance when you disconnected the feed lines and replaced them with 300ohm to 75ohm ?

I have read in hdtv primer that the feed lines on the 4228 are not properly designed as they do lose a few db of signal anything over chan 56. From my experience there is not much stations in our area that broadcast over chan 56 uhf freq so I could not tell if there is any real signal loss. We have City at 53 and Sun at 66

Why did you chose to side mount the antenna compared to stacking them as you lose the angle of coverage by side mounting.

Hmm you guys have me thinking, I might have to build a stronger support and stack a 4228 and see if I can pull in Rochester all year round since I have a rotor.

I will call channel master and ask them if the rotor can support a stacked 4228. I dont think so. :(

I just stacked two 4228 antennas. With alot of trial and error I finally got it to work right. I am getting alot more stations then I did before. I was wondering how many people have had any success with doing this?

Hi firemantom whoo nice. Question where are you located and what was the increase in performance with a signal antenna compared to a stacked 4228.

I did a test this past summer for stacking two 4221 vs a single 4228. I also ended up with great results using a 4228 and a 4221 on top without a rotor.

Since I sell rotors I decided to try one with a single 4228 vs the dual antenna setup a 4228/4221, the results was the same for Toronto and Buffalo channels. When the weather is warmer I can now reposition the antenna more east and the Rochester stations will now come in.

Did you compare signal with a atsc tuner signal meter, and what did you use to combine the signal a combiner or splitter in reverse.

Is both antenna stacked and pointed the same direction or pointed to slightly different?

Are you using a rotor as I dont think the channel master 9521 is strong enough to support a stacked 4228. Too much load on the motor.

I will call channel master and ask them if the rotor can support a stacked 4228.It should be fine Yaamon, because people have put dual VHFs on CM rotors and they worked okay with all that weight and rotational momentum to stop and start. If you ever need to go for a stronger rotor I would suggest a Yaesu or HiGain, which are brands that HAMs often use. Yaesu and HiGain have several models that handle different loads. I think a CM will do you fine though.

The new project is a Quad CM 2228 that is modified to improve feed design and will consist of 4 (32 Bay total) 4228s each with 7775 preamps...Sorry Bill I finally got a look at your photos and I've got the biggest smile on my face - you guys are really dedicated! :D Is your Yaesu rotor the one with the dual speeds? I'm just thinking that with the beam pattern I'm imaging the 32 Bay has you'd need to slew that array very very slowly for fine tuning of aim. Am I right about that?

Which location in East Texas - the way you guys are bundled up for the cold you look like honourary Canadians! ;)

Congratulations!

Hi firemantom whoo nice. Question where are you located and what was the increase in performance with a signal antenna compared to a stacked 4228.I live near Steubenville Ohio. I was not able to get all the Pittsburgh stations and the Cleveland stations, but now I can . I stacked them in the same directions using equal lengths of coax going into a two way splitter then into a CM 7777 amp.

That is incredible reception as you are almost 100 miles away from Cleveland. Great job. :)

Pittsburgh you are much closer 35 to 40 miles.

How high is your antennas mounted, did you point one antenna towards each city or are you using a rotor?

It is only 25ft in the air and I set down in a little valley too. I use a Channel Master rotator( CM 9521A) Tonights OTA reception is bad do to the heavy rains.:( Is a combiner better to use or splitter better?

Most splitters and combiners are similar, a real combiner is supossed to have a lower insertion loss .5db.

When you use a splitter in reverse the loss is not the same 3 to 3.5db as you are not splitting the signal and using the splitter in reverse.

Do you have any pictures of your setup that you could post.

Hmmm if the rotor as stampeder said is strong enough and others have used in a stacked configuration, I might give it a try in the spring and see if I can pull in WB 49.

This is the only station that I cannot get from Buffalo.

I thought what I have read that a combiner is better so I ordered "Channel Plus 2532" today. How much better will it help the signal? I am sorry I don't have any pictures yet. I spaced it about 42 inches which is 3.5 FT from the centers of each antennas.This site has allot of great info on it. http://www.hdtvprimer.com/ANTENNAS/16bay.html :cool:

firemantom26 a combiner is better, I did not mean they were the same performance, but similar in that you could use a regular two way splitter in reverse.

I used the channel plus 2532 with great results, good choice.

Hdtvprimer is a good site for information. When I was stacking the antenna I asked channel master and they said to space the bows evenly.

If I remember that was 7" apart you can measure with a tape measure the distance in between.

Iam not sure how much difference that will make, maybe you can try and see if the signal strength increases.

I spaced it 3.5 Ft from center of each antenna which is about 42 in from bottom of one antenna and top of the other other antenna.

I am very interested if any one else has had any info on how far they have spaced the two antennas.

I have tried several ways to configure and locate my 4228 antennas. The best results to date was to stack vertically, overlapping screens so bowties are equally spaced. I connected the 2 balun terminations with 2 length of #12 copper wire then soldered 1 balun midway on the copper wires thus doing away with the splitter.Antennas are on 10' x 1.5" galv. pipe on a RS rotor.(if it breaks it breaks).
I live in a fairly high area of south Surrey and am pulling in all digital network channels most of the time from Seattle 96 miles away.

Jaygeetee
So how much better is it soldering the baluns together vs. using a combiner and how big is it to have the spacing like you have it set up? Have you ever messed with tilting the antennas vertically?:cool:

I spaced it 3.5 Ft from center of each antenna which is about 42 in from bottom of one antenna and top of the other other antenna.

I am very interested if any one else has had any info on how far they have spaced the two antennas.

Sorry folks,I was wrong I spaced it 42 ins (3.5 FT) from center of each antennas.:eek:

Have you ever messed with tilting the antennas vertically?See posts #78 and #80 in this thread about antenna tilting: http://www.digitalhomecanada.com/forum/showthread.php?t=29559

4228 help

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The way I am going to try it is two equal lengths of coax coming off each baulms into two 7777 amps, run two coax cables "RG6' into the house, then into the power supplies, than combine them at that point, then from there into the TV. What were the best results you have had on spacing each antennas? I have them with each bow tie at equal lengths. I had to over lap the screens to do this. what do you think. How important is the spacing of each antennas?
Thank You
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The way I am going to try it is two equal lengths of coax coming off each baulms into two 7777 amps, run two coax cables "RG6' into the house, then into the power supplies, than combine them at that point, then from there into the TV.That's a succesful way of combining two different types of antenna, such as a UHF and a VHF, but it is not "ganging", so I don't believe you'll get the true benefit of a "stacked" unified reception pattern from your two CM4228s. Also you run the risk of the signal getting out of phase, in which the 2 antennas will cancel eachother out or the two CM7777s being the tiniest bit different in their output levels. When the tuner tries to take in Channel 37, it might get 2 strong signals but a tiny bit stronger signal on one over the other, which could cause problems.

Here's a different method: run 300 ohm twinlead (sheilded would be even better if you can find any, and NOT 75 ohm coax) from the top antenna's output connection out the back of the reflector down and back inwards to the bottom antenna's output connection. Next, remove the twinlead so that you can cut it EXACTLY half way (precision is important) and strip the ends equally, then reinstall it as before but temporarily clamp one balun into place at midpoint where the 2 top and 2 bottom ends meet. Run RG6 from the balun into one 7777 and then to the power injector inside. Test by watching a medium strength TV station, and switch the ends of the twinlead or balun as needed to prevent any phase cancelling until the picture is clean and strong. When you get it right, solder it into place and tape/silicone it up. You will now have a "ganged" pair of antennas operating as one.What were the best results you have had on spacing each antennas? I have them with each bow tie at equal lengths. I had to over lap the screens to do this. what do you think. How important is the spacing of each antennas?Check Yaamon's previous posts about that. He did the same thing, making sure the bowties were precision spaced.

First, remember that a CM4228 is actually two CM4221s mounted side-by-side on crossbars at the factory, but Channel Master uses metal rods to connect their outputs at a central joiner for connecting a balun. The author of HDTVPrimer suggests that CM's solution is not as good as can be for signal strength, so I will be running some tests in the Spring time. I don't have a db meter or a spectrum analyzer, so I'll be using the signal meters on 2 different ATSC tuners, and my good ol' eyeballs and ears. ;)

Step 1 of the test will be to connect one CM4228 and take signal strength readings as a baseline for further testing.

Step 2 will be to stack two CM4228s joined together into one balun and take signal strength readings as a baseline for further testing.

Step 3 will be to mount one CM4228 but replace the metal rods with 300 ohm copper wiring and re-run the tests. If testing reveals no benefit over Step 1, I'll abandon the testing and conventionally stack a pair of CM4228s. If better signal strength and/or cleaner picture is found over Step 1, I will go to Step 4.

Step 4 will be to stack two Step 3 modified CM4228s to a central balun for the RG6 downlead. I would expect to see Step 4 offer benefits over Step 3.

Step 5 will be to stack two CM4228s but run custom 300 ohm copper wiring directly from the outputs of each of the four CM4221s into a precision measured 300 ohm "X" pattern of copper wire to a central balun for the RG6 downlead. I'm hoping to see if Step 5 offers any additional benefits over a stacked Step 2 pair.

My hope is to come up with the best possible way of combining stacked CM4228s.

If anyone has tried anything similar to this, please either give me some advice or stop me from wasting my time! :D

4228 help

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The way I am going to try it is two equal lengths of coax coming off each baulms into two 7777 amps, run two coax cables "RG6' into the house, then into the power supplies, than combine them at that point, then from there into the TV. What were the best results you have had on spacing each antennas? I have them with each bow tie at equal lengths. I had to over lap the screens to do this. what do you think. How important is the spacing of each antennas?
Thank You
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I finally got the set up done over the weekend. I did it a little different set up. I connected two copper wires to each wing nuts on each antenna, than ran one baum in the middle of each copper wire, than I add two CM 7777 amps to a combiner.than into the house. off there I split off each lines into it's own power supplys. So far it seems to working well. I will let you know more in a few days

I stock and sell the 4221 and 4228 antennas.

Also stock 9521, 7775, Winegard AP4700 pre amps too, and tripod mounts etc.