# 2 Bowtie vs CM 4221



## MoInSTL (Jan 25, 2006)

I'm using a roof mounted, direct run (no diplexors) 2-bay double bowtie on a J-mount mast from D* with pretty good results. It required precise aiming.

I get anywhere from 82-92 signal strength on all network channels using an HR10-250. PBS is unwatchable at 65. I get periodic drop outs that last a second especially when windy (lots of big trees) on all channels. Wondering if a 4-bay CM 4221 will do the job better at pulling in PBS and help with less macroblocking overall. I'm guessing if a 2-bay is for the most part good, a 4-bay will be better. Does this sound correct? 

The following channels are listed from antennaweb in the the "red" zone.
FOX 180° 13.7 43 
CBS 164° 14.6 56 
ABC 167° 10.8 31 
WB 167° 11.3 26 
NBC 169° 11.6 35 
PBS 184° 17.4 39 

Thanks in advance!


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## MiamiTV (Apr 8, 2003)

Yes Bigger is better. At least for my system, it helped big time


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## MoInSTL (Jan 25, 2006)

Which antenna are you using? It looks like 11.4dB and 13.7dB is the difference. I know nothing about gain, so no clue as if that's a little or a lot between the two. On the face of it, it doesn't seem like much difference.


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## kimsan (Jan 23, 2002)

MoInSTL said:


> Which antenna are you using? It looks like 11.4dB and 13.7dB is the difference. I know nothing about gain, so no clue as if that's a little or a lot between the two. On the face of it, it doesn't seem like much difference.


I'm in a Blue and Purple range for my HD stations. Both are within a couple degrees and ~30 miles distant. I've got a CM 4228 and spotless (when it's not too foggy) OTA reception.

CM 4221 is kind of the gold-standard for directional OTA and the 4228 is more directional with more gain. I opted for the 4228 to try and overcome summer foliage. It helps...at least some 

Most B&M shops will take a return if you find it's not much of a difference. It's not *that* much of a cash outlay compared to the HR10 or an HD set, is it?


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## A J Ricaud (Jun 25, 2002)

MoInSTL said:


> Which antenna are you using? It looks like 11.4dB and 13.7dB is the difference. I know nothing about gain, so no clue as if that's a little or a lot between the two. On the face of it, it doesn't seem like much difference.


2.4 dB is significant. 1 dB = a difference of 1.25 times; 3 db represents a doubling.


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## MoInSTL (Jan 25, 2006)

A J Ricaud said:


> 2.4 dB is significant. 1 dB = a difference of 1.25 times; 3 db represents a doubling.


That's the answer I was looking for. Thanks for taking the time to let me know. I figured if a 2-bay was working good a 4-bay would be better. I just needed confirmation. I'll be picking up the 4221 and give it a try after the snow on the roof melts.

Kim, since D* left a foot plate in the center of my roof when they moved my dish I currently have the 2-bay mounted on the J-mast so I am limited to what I mount to it. I just can't deal with anymore holes going into my new shingles (and it seems like a good spot for getting signals). I am lucky enough to have a local dealer that will sell to the public at wholesale prices. They already let me return the Square Shooter. I have read nothing but great reviews on the 4228, but I think I'll be fine with it's little brother. Less worries about wind too.

Thanks again to you both.


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## TyroneShoes (Sep 6, 2004)

MiamiTV said:


> Yes Bigger is better...


More accurately, for DT, more directional is better. And higher is also usually better.


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## TyroneShoes (Sep 6, 2004)

MoInSTL said:


> Which antenna are you using? It looks like 11.4dB and 13.7dB is the difference. I know nothing about gain, so no clue as if that's a little or a lot between the two. On the face of it, it doesn't seem like much difference.


Higher gain _usually_ implies better directionality, so you can generally assume that an antenna with higher gain will also be more directional. You are usually not all that worried about gain, as that can easily be manipulated after the fact in most cases (other than extreme fringe reception). If you have a multipath interference issue, the best arrow in the quiver is directionality. Get the antenna with the best directionality for the frequencies of interest to your reception scenario, typically a 4228 or a DB8, and worry about too much or too little gain afterwards (that's the simple part). hdtvprimer.com has a lot of good info on OTA reception.


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## MoInSTL (Jan 25, 2006)

TyroneShoes said:


> Higher gain _usually_ implies better directionality, so you can generally assume that an antenna with higher gain will also be more directional. You are usually not all that worried about gain, as that can easily be manipulated after the fact in most cases (other than extreme fringe reception). If you have a multipath interference issue, the best arrow in the quiver is directionality. Get the antenna with the best directionality for the frequencies of interest to your reception scenario, typically a 4228 or a DB8, and worry about too much or too little gain afterwards (that's the simple part). hdtvprimer.com has a lot of good info on OTA reception.


I agree, antennaweb suggests a medium directional. My 2-bay should not work. I got it for free from D*so I decided to try it anyway. It took quite a bit to get it aimed just right

I should have clarified a couple of things. D* originally mounted my dish in the center of my roof. Then when they came back out the tech decided to move the dish to a much lower point on the roof and mounted the 2-bay next to the dish. I only picked up 2 channels. I took the mast and antenna and mounted it higher in the center of the roof and picked up the 4 network channels I wanted. Unable to pull in PBS however. I went to mount the CM 4221 and found the J pipe was too short to mount both brackets as they are 30" apart. In the process, I moved the mast a tiny bit by accident & PBS comes in great now.

I decided on the CM 4221 as a measure against windy weather and heavy overcast. I was hoping I would get fewer ever so brief drop-outs. Most of the time I get none. This may be flawed logic.  I got a 38" straight mast for the CM. Because I don't want more holes in my roof it needs to stay where D* originally mounted the plate (as well it being as a good spot for receiving signal). The CM 4228 while it gets great reviews, is too big and I worry about high wind which I get and since it's at the highest point in the center.

Btw, I read all the pages at hdtvprimer.com before I started this quest and it has great info. The drawings on gain were confusing and went over my head but still helpful. I just need to work with what I have. If it doesn't, I will try another solution. But all possibilities really center on what fits on the plate already bolted through my new shingles.

So given the chart at antennaweb in my original post what do you think? The snow has melted and just waiting for it to warm up before trying the 4221.


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## Runch Machine (Feb 7, 2002)

The 4221 is a great antenna. It should work well for you and give you reliable reception in all conditions. I have one in my garage attic and no matter what the weather is doing, I get perfect reception. It is good to have the extra signal strength to overcome static that occurs from lightning during heavy storms.


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