[Agrajag]

I couldn't decide between a Radio Shack Yagi HD antenna and a Channel Master 4228 and since they weren't that expensive I bought both. Now that I have them both, I got to wondering if I can actually hook up both (I went with the RS antenna as it had a wider range. I'm thinking I could use the 4228 to bring in some other channels, perhaps from mid-NJ or to bolster the Philly stations. Is it possible to run antennas in series and boost the signal the way you might with a dish array?

 

[Nitewatchman]

This is actually more of a complicated subject than you might imagine, but the short answer is no, you would most likely not want to combine seperate, broadband antennas of different make/model onto the same feedline.


Here's some excellent info concerning stacking/Combining antennas, which explains why what you want to do is not a good idea :

http://www.kyes.com/antenna/stacking.html


While it is possible to stack antennas for increased gain/directivity, it is very tricky and each antenna hooked together has to be exactly the same "model" and aimed in the same direction. Spacing and proper mounting/connections/phasing/etc. are key, and stacking is usually most beneifical over just a narrow range of frequencies.


Here's a good article on stacking antennas:

http://pages.cthome.net/fmdx/stackant.html


There are also a few excellent threads concerning combining or stacking antennas that go into much more detail, and provide much better info than I am attempting here, but I don't have the links handy, perhaps someone else has them available ...


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The above links do a better job than I can of explaining things, but here are a few points :


You CAN combine seperate VHF and UHF antennas together with a VHF/UHF combiner or by using seperate VHF/UHF inputs on a preamp/etc.


Something which you could do with your antennas that might be useful would be to use seperate feedlines for each antenna with a A/B switch near receiver to aim different antennas in different directions w/o needing a rotor.


However, Even with the antennas on seperate feedlines, spacing the antennas on the mast is important as well, If the antennas are too close together, one can affect the other(and not in a good way). 1 wavelentgh spacing for the lowest frequency you will be using/your antenna is designed for is best, however in many instances you can get away with spacing them closer together than that ... More info on this in the first link I provided above ...


Another thing that is possible is, you can combine antennas onto the same feedline using a CM Jointenna(if you can still get these, I've heard of them here on AVSforum, but I've never used one), which allows you to aim, and use one of your antennas for one, specific channel.


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The main problem with what you are wanting to do is that the results would likely be very, very unpredictable, and it's quite likely that one antenna will "cancel out" the performance of the other antenna on at least certian frequencies/etc, and increase problems such as multipath/etc.


In other words, one antenna is likely to affect the other one in a delitirous manner, and you'll end up with something which will "operate" in a very unpredicatable manner(much like what we call a "random wire antenna"), instead of as the directional, hi-gain antenna which your antennas as used seperately would be.


Some folks do seem to have some luck occasionally with this sort of thing though, and can effectively use one antenna to help "phase out" interference problems, or at least some of the signal from a strong, unwanted local station in order to receive a station well on an adjacent channel -- But, again, it might work well for one channel(unpredicatably), but work horribly on another desired frequency/station you wish to receive.

 

[greywolf]

Try

http://www.avsforum.com/avs-vb/showt...78#post1497178

http://www.avsforum.com/avs-vb/showt...66#post2159466

http://www.avsforum.com/avs-vb/showt...90#post2432890

 

[magic123]

antennas..


Bottom line. I have found the best way to bring in digital stations is to purchase top of line antenna such as Televes, a rotator from Channel Master (9521A) and a pre-amp for stations (30 miles plus). Mount the antenna as high as possible! Be sure there are no close obstructions. It is important to 'zero' in on each station and get 100 percent on any 'signal meter' you may be looking at. This should bring in stations up to 60 miles. Over that distance, it becomes a question of many things. Good Viewing!

 

[Agrajag]

In my ignorance I ran into a few suprises. First, I thought this antenna would also pick up solid VHF. Of course it doesn't so now it's either the digital feed or nothing (I do get signal but it's snowy). Second, being where I am in NJ puts me in the center of two tower areas with one to the west and one to the north. I can live with the way it is now getting 85% of what I want out of the west but there are a few channels to the north I'd like to get that right now are getting no signal. For example, NJ's channel 52 is running 5 feeds off their digital all with unique programming so it's like getting 5 more channels. Right now I don't get that at all.


I also cannot find a source for these Televes antennas and the 75 that is recommended would present a small problem based on the way it's attached to the mast. It's not connected on the end but on the center and that would get it too close to my dish.

 

[Darin]

You don't say what channels you are trying to receive. The jointennas can help a lot in such a situation, but unfortunately they are not tuned "per channel" for UHF like they are for VHF. They cover a range of channels (in three groups). If all of your northern channels are higher frequencies like channel 52, and all your western channels are lower, then you'd probably have a pretty good chance of using two antennas with a jointenna. Basically, all a jointenna is is a splitter/combiner, with filters in the two legs. If leg "A" is filtered such that only frequencies w-x are allowed to pass, and leg B is filtered such that everything BUT frequencies w-x are allowed to pass, then the two antennas don't don't interfere with each other. Leg "C" sees the entire range of frequencies, but they come from different legs.


You can see more info about them here .


There are more selective filters that would allow you to mix/match channels to directions rather than being stuck with the three ranges of the jointenna, but filters that are that accurate and selective get VERY expensive.


Most likely, the only practical solutions if the channels don't work well with that's available in the jointennas would be the already mentioned switch, rotator, or maybe if you're really lucky you can find a heading for the 4228 that's able to pick up everything, using the pick-up pattern to your advantage.

 

[Nitewatchman]

Agrajag,


You might also want to check out the threads for your area in the local info area of AVS for info on the stations and how others are pulling them in. There is an excellent thread concerning OTA reception in N.J. Here:

http://www.avsforum.com/avs-vb/showt...hreadid=233490

 

[hornmdt]

I have one of the Channel Master Stealtenna HDTV antennas. I get good reception for all the local DTV signals in Charlotte, but DirecTV puts some channels in the guide that I cannot get. They are pretty much 180 degrees from the direction I need to point my antenna to pick up the local high def channels.


I'm think about adding a second antenna and pointing it north (180 degrees) so I can pick up the additional channels.


After reading through this forum, it does not sound like an easy thing to do as I had hoped. I'll need to vertically stack the antennas due to physical restraints, and also use some sort of coupler I assume. I do not know how much distance must be between the antennas vertically. The Stealtenna picks up VHF as well as UHF but I'm primarily interested in the UHF channels, which is where the DTV channels are located in all the areas around here.


Does this sound feasible? I do not want to use a rotor or an A-B switch.


Thanks