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Discussion Starter · #1 ·
I just received the engineering data from Channel Master on the new 4221HD and the 4228HD models imported from China that replaced the tried and true US made versions.


Some of the figures seem inconsistant. I have not yet inquired about this, but will.

 

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Thanks for posting these. I had looked on their website and could not find them. My parents need an antenna to pick up OTA stations that are about 120 degrees from each other. If I can't get good reception for them with the 4228 as shipped, what should I expect to happen if I "folded" the 4228 vertically along its centerline so that the left half of the bow ties point to one transmitter and the right half of the bow ties point to the other transmitter? The alternative might be to buy two separate antennas and combine them with equal length leads but I would like to hear thoughts on vertically folding the 4228.
 

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Discussion Starter · #4 ·
Here is the whole table that includes the orginal 4221/4228.


I contacted CM questioning some of the figures. Noteably, the very wide BW on ch 11 (4228HD), the very narrow BW on ch. 35 & especially ch. 27 (4221HD) and a few other inconsistencies that are probably typo's.


Looking at just the gain figures, the 4221HD is just as good as the 4228HD, the difference being poorer F/B ratios.

 

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Quote:
Originally Posted by Burl /forum/post/15491106


what should I expect to happen if I "folded" the 4228 vertically along its centerline so that the left half of the bow ties point to one transmitter and the right half of the bow ties point to the other transmitter?

1) You'd break the transmission lines and get nothing.


2) assuming you worked around problem #1, you'd most likely create a whole bunch of ghosts a/o wacky peaks and nulls in the response pattern.


In short, not a good idea.
 

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Quote:
Originally Posted by HDTVChallenged /forum/post/15515102


In short, not a good idea.

Thanks for the reply. I guess I'll keep my fingers crossed that I can find an antenna and position it so that it will pick up both directions satisfactorily.


Jeff
 

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Quote:
Originally Posted by Burl /forum/post/15517881


Thanks for the reply. I guess I'll keep my fingers crossed that I can find an antenna and position it so that it will pick up both directions satisfactorily.


Jeff

It depends on how strong the stations are. You can take 2 4221s and stack them horizontally and phase them so they no longer have a strong center lobe, but dual or quad forward lobes.


According to the chart at HDTVPrimer is works ok, up to about a 60 degree spread on the first lobe with no center lobe. And up to about 120 degrees on the second lobes, if they are feed out of phase with each other and the correct distance per channel.


That is a lot of ifs to get right. I don't know anyone that actually tried it.


At 120 degrees, if out of phase you would be on the secondary lobes. That actually falls off their displacement chart. So you might have nothing more than a unity gain directional antenna array.


If there is a station between them you could run them in phase and try and adjust the first side lobes for the 120 degree spread. Again, you won't have any gain when you are done.


Myself if I didn't want a rotor would be inclined to buy 2 UHF log-yagis and point them 120 degrees apart, pray you don't get mulitpath or try and adjust the 2 so you don't.


Here is a page with the phasing info

http://www.hdtvprimer.com/ANTENNAS/ganging.html
 

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Cool. This is very helpful. If the single antenna doesn't work, I'll give the 2 antenna approach a try.
 

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Quote:
Originally Posted by Burl /forum/post/15548790


Cool. This is very helpful. If the single antenna doesn't work, I'll give the 2 antenna approach a try.

When looking at the chart, remember it's hard to get 2 UHF antennas stacked horizontal much closer than 20 inches.


That is why I suggested just point two yagis.


Another way that is less experimental is to run 2 coaxes , one from each antenna and put an antenna switch by the TV. Then you have less trouble making sure you don't get mulitpath. That would be a good thing to try if you can't get two into a combiner to work the way you want.
 

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Quote:
Originally Posted by videobruce /forum/post/15484351


I just received the engineering data from Channel Master on the new 4221HD and the 4228HD models imported from China that replaced the tried and true US made versions.


Some of the figures seem inconsistant. I have not yet inquired about this, but will.

So, would I be wiser to purchase the older 4221 instead of the newer "HD" version? The furthest station is 30 miles from my location.
 

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Quote:
Originally Posted by videobruce /forum/post/15510797

...Looking at just the gain figures, the 4221HD is just as good as the 4228HD...
Except for VHF 7 thru 13 on the 4221HD, which isn't known. I have two channels in this band, and would like to know what gain (if any) the 4221HD has for those.
 

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Quote:
Originally Posted by HDTVChallenged /forum/post/15550304


Yep ... get 'em while you can.

Well, I found they are increasingly harder to find online. I did notice that ACE Hardware shows them in stock on their "superstore" website. So, I called my local ACE and they don't carry them, but can order them in for $32.


Should be here next Wed.
 

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Quote:
Originally Posted by SlammedNiss /forum/post/15551681


Well, I found they are increasingly harder to find online. I did notice that ACE Hardware shows them in stock on their "superstore" website. So, I called my local ACE and they don't carry them, but can order them in for $32.

Yep ... that's a good place to look for them. In the past, my local ACE usually had one or two in stock, but I haven't been in that store for awhile so things might be different.
 

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Quote:
Originally Posted by SlammedNiss /forum/post/15551681


Well, I found they are increasingly harder to find online. I did notice that ACE Hardware shows them in stock on their "superstore" website. So, I called my local ACE and they don't carry them, but can order them in for $32.


Should be here next Wed.

I probably bought my second one from the same source. Arrived as expected. I think it was near $40 with my shipping to Florida.
 

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Quote:
Originally Posted by arxaw /forum/post/15550941

Except for VHF 7 thru 13 on the 4221HD, which isn't known. I have two channels in this band, and would like to know what gain (if any) the 4221HD has for those.

It has a teeny tiny bit of performance on 11, 12 , 13, but not enough to say it works. Not enough to even publish engineering specs.


Lets say you have a ton of signal on VHF (-20dbm) it might work.


If asked yes or no, the answer in no, it's doesn't have any VHF properties.
 

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Quote:
Originally Posted by Piggie /forum/post/15554191


It has a teeny tiny bit of performance on 11, 12 , 13, but not enough to say it works. Not enough to even publish engineering specs.


Lets say you have a ton of signal on VHF (-20dbm) it might work.


If asked yes or no, the answer in no, it's doesn't have any VHF properties.

Thanks.
 

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If you wade through the Build a UHF antenna thread you will see the screen and whiskers are too short on the HD4221 to be of any use on VHF.


In that price range Winegard has the new 759xP series that is priced decent.
 

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Quote:
Originally Posted by SlammedNiss /forum/post/15551681


Well, I found they are increasingly harder to find online. I did notice that ACE Hardware shows them in stock on their "superstore" website. So, I called my local ACE and they don't carry them, but can order them in for $32.


Should be here next Wed.

Well, called them up and it didn't come in. They said the warehouse was out and would ship when they got restocked. Considering they aren't produced anymore, I bought one from onestopshopcatalog.com instead.


BTW, I did try ordering it from the ACE online superstore, but couldn't get through to a single person. Even their customer service extension came back as "unavailable at this time."
 

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Quote:
Originally Posted by videobruce /forum/post/15484351


I just received the engineering data from Channel Master on the new 4221HD and the 4228HD models imported from China that replaced the tried and true US made versions.


Some of the figures seem inconsistant. I have not yet inquired about this, but will.

I dont want to get to political here. But consider the US made ones were less expensive. Why even consider these antennas any more.


Are the DB4 and 8 made in America still? They are a better price. For most people unless they are 10 miles or less from a VHF there isn't enough VHF reception from them to consider them a VHF antenna.
 
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