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Channel Master OTA Gear & Antennas

290K views 657 replies 153 participants last post by  oldtvguy 
#1 ·
I am looking for suggestions. I currently get all the Buffalo DTV stations between 75 and 98% with my Silver Sensor but I only get WNLO from 20-40%. I just need a small boost as to not create problems with the others. can anyone provide suggestions on a good booster for me and where to find it. Thanks.
 
#277 ·
firemantom26 said:
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.
firemantom26 said:
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.
 
#278 ·
Some Tests on a Stacked CM4228 Pair I'll Be Running In the Spring

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
 
#279 ·
firemantom26 said:
4228 help

--------------------------------------------------------------------------

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
__________________
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
 
#281 ·
Angling CM4228's upwards ?

The HDTV primer article on ganging two CM4228's shows them on a special bracket that angles them upwards about 10 to 15 degrees ... is there any tru benefit to this ? Does it get you signals that bounce or skip overtop mountains ( or trees ) a bit better ? I have a single CM4228 and if doing this will help me get Seattle stations from Vancouver then I'm up for it. Thanks,...Dave J
 
#282 ·
#283 ·
4221 X 2 vs. 4228+9521

In Brampton (410/Bovaird) what would be a better set-up, stacked 4221 with 1 pointing to Buffalo and the other to the CN tower or a 4228 on a rotor. Keep in mind that this will be fed to 3 tv units that could be watching different Buff/TO channels simultaneously????
 
#284 ·
tataynik said:
In Brampton (410/Bovaird) what would be a better set-up, stacked 4221 with 1 pointing to Buffalo and the other to the CN tower or a 4228 on a rotor. Keep in mind that this will be fed to 3 tv units that could be watching different Buff/TO channels simultaneously????
somehow I am not able to edit my post, I guess it it's not an option after a few hours !!

If I do the stacked 4221 do I need to use one of these instead of joiners/splitters?? They are mast mounted.

Join-Tennas
(For blocking or passing of a single channel)
The Channel Master JoinTenna is perfect for those situations when you need to add a second antenna to pick up a broadcast station in another direction but don't wish to use a single antenna and rotator. The JoinTenna blocks all frequencies but the one it is tuned for, eliminating the ghosting and reflection that can happen when you connect two antennas together. There is a Join-Tenna coupler for every VHF and UHF channel - simply select the model number and specify the channel you wish to receive or block!
If I do , which model should I get??

UHF Channels ----- Model Number*
14-29 ---------- 0585-1
30-49 ---------- 0585-2
50-69 ---------- 0585-3

Thanks in advance. BTW, I am using Sammy SIR TS160 on 1 unit, built in on other 2 tv's. :)
 
#285 ·
Tataynik I would try the just pointing the antenna at the Buffalo stations .The Toronto stations may still come off side lobe.If that does not work, then add second antenna at Cn tower and use some A/B switches.Either antenna will work if its high and has a clear view to south and slightly east
 
#287 ·
I wasn't aware of those "Join-Tennas". I had issues with my 4228 and purchased a rotor. After mounting the rotor, I found that aiming the antenna at WGRZ-DT gave me tons of signal on all Buffalo channels and most TO channels. Unfortunately, I lost CITY-DT. I can move my rotor to get CITY, but I might consider adding a second smaller antenna and pointing it towards the CN tower. Are those Joinantennas for a range of channels or are they for a specific channel? Most ordering sites ask you to specify the channel.

I take back everything I said about my 4228 earlier in this thread. The antenna is VERY strong. The problem was it was aimed incorrectly. When my neighbour and I aimed it, it was a very warm day and I've since learned, that hot days can give you misleading signal levels. That was why I was getting droupots in bad weather (my aim was off about 20-25 degrees). In fact, I'm considering removing my preamp when we get some better weather (I'm currently splitting twice to knock the signal levels down).

Some strange observations:

-WNLO-DT (32) used to be my strongest signal. Now, 14 and 43 are stronger. Considering WNLO is at 1000 KW and the others are 35 KW and 156 KW, why is that the case? Even 38 and 39 are now a bit stronger than 32.

- I can no longer receive CITY-DT unless I repoint my antenna towards Toronto. However, rain causes CITY-DT and SUN-DT to come in VERY strong. Is this caused by reflections?
 
#288 ·
jeneral I noticed the same.The signal meter is not just measuring signal strength.The preamp may have some ability to not over amplify a signal.If I remove the preamp then wnlo-dt on 32 is then the strongest.With the preamp the weaker signals then appear stronger.The signal meter may measure errors and noise and not actual signal voltage.
 
#289 ·
As you mentioned, a Join-Tenna is a single channel device. Here is a schematic from Channel Master:



Therefore I would recommend either a rotor (less than 20 seconds to move from Buffalo to CN Tower azimuth) or 2 separate antennas into a low-loss joiner. See the OTA Signal Gear thread for info on joiners.
 
#293 ·
Hi, I've been using my CM4228 for the locals here in the Vancouver area and its been excellent, so I'm reluctant to mess with a good thing. If I can figure out a tower solution that will let my antennas see over the huge trees on my property and let me take them down easily to hotrod them I'll revisit my SeaTac reception ideas. Sorry, but its all on hold these days.

I think hotrodding a CM4228 for deep fringe is probably worth it based on the comments about the Channel Master feeds by the fellow at hdtvprimer, so if someone was about to try to restring a CM4228 I'd suggest using brand shiny new shielded 300ohm copper twin-lead cable wherever possible, in the shortest lengths possible to get the job done, before it feeds into a balun.

I hope to try this soon, and maybe in a stacked CM4228 pair! ;)
 
#294 ·
cm4228 'hotrodding'

I too was waiting for results...have stacked 4228s equal spaced bowties, 1 balun connected equadistant to #12 copper wire running parallel between exsisting balun terminals. Replaced #12 copper with regular 300 ohm twin lead but got poorer results and went back to copper. I wonder if better quality 300 ohm twin lead (and where would I get it) would get better results?
This week has been great for Seattle reception, even KOMO 4.1 was booming in.
 
#299 ·
Near Philadelphia, PA

I am looking at the CM 4228 that would need to be mounted in the attic of my 2 story home.

I hope you guys can help me? I have been researching this for awhile now. I have a Dish 811 Reciever and want to get my Digital HD locals through OTA .I am only looking for the following channels.

blue - uhf
WPSG 57 UPN PHILADELPHIA PA 27° 62.9 57

blue - uhf
WTXF 29 FOX PHILADELPHIA PA 27° 62.9 29

violet - uhf
WPHL 17 WB PHILADELPHIA PA 27° 63.0 17

violet - vhf
WCAU 10 NBC PHILADELPHIA PA 27° 63.2 10

violet - vhf
KYW 3 CBS PHILADELPHIA PA 27° 63.2 3

violet - vhf
WPVI 6 ABC PHILADELPHIA PA 27° 63.2 6



Thanks
 
#300 ·
Edit original posts.The location by Zip was wrong and I only want Digital Stations.
* violet - uhf
KYW-DT 3.1 CBS PHILADELPHIA PA 31° 54.9 26
* violet - uhf
WYBE-DT 34.1 PBS PHILADELPHIA PA 31° 54.9 34
* violet - uhf
WPSG-DT 57.1 UPN PHILADELPHIA PA 31° 54.9 32
* violet - uhf
WPVI-DT 6.1 ABC PHILADELPHIA PA 31° 54.9 64
 
#301 ·
OTA in the U.S.A.

Hi smaerd58,

Regarding OTA results and questions from the U.S.A. I always direct people to the 30+ years of experience of a fellow named Tigerbangs, who offers his knowledge and advice over at the Home Theater Spot:

http://www.hometheaterspot.com (look for The Antenna Spot forum)

We're actually better set up here for Canadian OTA, but you are always welcome here anyways.
 
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