So I have a question about stacking antennas...I currently have a cm-3020 vhf and uhf combo antenna and im thinking about adding a 91 xg uhf only antenna...my question is can I use a combiner to combine the two with out causing the two to interfere with one and other and cause signal loss
stacking 2 antennas
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It depends how much of a difference in angle of the antennas. You can just get something like http://www.solidsignal.com/pview.asp?p=uvsj to combine just using 1 for UHF and one for VHF.
Yes it should work. I used 3 different antennas for a while (VHF-Lo, VHF-Hi, and UHF) and used a 3 band combiner for it.
What are you trying to do, get more gain for farther away reception, receive channels from more than one direction, or use one antenna for VHF only and the other for UHF only?
Stacking antennas, [usually one above the other, 3 feet or so apart, there is formulas to figure out the distance] works much better if the antennas are both the same model and the cables from both must be the same length, stacking you'd do to receive stations from more than one direction.
If you want more gain, you'd gang the antennas together, putting them side by side. Same as stacking, using two different types of antennas probably will not work well and the cable lengths must be the same.
If you want to use the CM3020 for VHF only and the 91XG for UHF only, then do as Mike123abc suggested and make sure your cables from both antennas are the same length. That might not be the best though, depending on what it is you want to achieve with this. The CM3020 is a deep fringe ant. and the 91XG is a uni-directional, the 91XG might not pull stuff in from as far away on UHF as the CM3020.
If you only want to try and increase reception and you haven't already bought the 91XG, a good pre-amp may be a better way to go than stacking/gaining another antenna if you don't already have a pre-amp.
Stacking antennas, [usually one above the other, 3 feet or so apart, there is formulas to figure out the distance] works much better if the antennas are both the same model and the cables from both must be the same length, stacking you'd do to receive stations from more than one direction.
If you want more gain, you'd gang the antennas together, putting them side by side. Same as stacking, using two different types of antennas probably will not work well and the cable lengths must be the same.
If you want to use the CM3020 for VHF only and the 91XG for UHF only, then do as Mike123abc suggested and make sure your cables from both antennas are the same length. That might not be the best though, depending on what it is you want to achieve with this. The CM3020 is a deep fringe ant. and the 91XG is a uni-directional, the 91XG might not pull stuff in from as far away on UHF as the CM3020.
If you only want to try and increase reception and you haven't already bought the 91XG, a good pre-amp may be a better way to go than stacking/gaining another antenna if you don't already have a pre-amp.
Thanks for the info...Im trying to get reception from channels that are farther away from my location...I already have a channel master 7777 preamplifier...any idieas on trying to add gain to my antenna set up....my zipcode is 17250...I checked tv fool and was wondering what all I could get...
That's a good pre-amp, 30 db gain on VHF and UHF. How high is your antenna and where is it located, on the roof, in your attic, etc? Are all your cables RG6?
If you can post your TV Fool report in this thread, a bunch of people on here are really good at figuring out what you should be able to get for stations.
If you can post your TV Fool report in this thread, a bunch of people on here are really good at figuring out what you should be able to get for stations.
My setup currently is a cm-3020 antenna with a channel master 7777 pre amp on a 40 ft tower and im using rg 6 cable and an antenna rotator...my zipcode is 17250...not sure how to put a link from tvfool on here...im using my phone cause im at work right now...if someone could look at my tvfool report and tell me what channels I should get it would be greatly appreciated.
Posted your Tv Fool report for you below, there's an awful lot of grey stations there, meaning very weak .... with a 40 foot tower and fringe ant, good pre-amp and rotor, you've already got quite a good setup, not anything more that I can think of that you could do to make that better really, unless you gang a few antennas together.
This site describes the basics of stacking and ganging antennas to give you an idea of it. Your mileage might vary in doing it, depending on the distance of you from towers and the terrain in between.
http://overtheair.saveandreplay.com/Antenna_Stacking_Ganging.asp
Let some people on here look over your Tv Fool report and maybe someone will have an idea or two, are there any stations in particular that you were hoping to get?
This site describes the basics of stacking and ganging antennas to give you an idea of it. Your mileage might vary in doing it, depending on the distance of you from towers and the terrain in between.
http://overtheair.saveandreplay.com/Antenna_Stacking_Ganging.asp
Let some people on here look over your Tv Fool report and maybe someone will have an idea or two, are there any stations in particular that you were hoping to get?
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I was hoping to get wvir channel 29 and wdtv channel 5...they are over 100 miles away tho so that may be out of the question...I got mountians to the north and to the east blocking the channels from Baltimore and dc...but the 2 channels I mentioned are to the south and west so I might have some hope...just looking for some idieas cause my rotator is broke so im gonna have to take the whole antenna set up down and replace it with a stronger rotator...while I have it down I was thinking of changing my set up to get more gain...
You are in my back yard. Way to many hills and valleys to use a generic zip code report. Run a report for your exact location and post a link.
WVIR and WDTV will not happen, just to far away. Based on the current report you are looking at a couple of PBS stations, NBC Hagerstown, ION and WJAL.
WVIR and WDTV will not happen, just to far away. Based on the current report you are looking at a couple of PBS stations, NBC Hagerstown, ION and WJAL.
What channels can you receive now? Where is your antenna pointed with the broken rotator, at about 237 degrees you may be able to receive most of your channels?
Right now the antenna spins around when the wind blows...I guess the bearings are shot in the rotator...when it was working I got all the channels down to watm channel 23 with -19 db on the tv fool list...i was wondering what is the lowest nm reading for a channel that I could pick up.
If you were getting 23.1 at 75 miles that may be as good as it gets, for UHF 24 that is pretty good reception.
Boba's right, that may be as good as it gets, that is pretty good all ready. You can figure it out, theoretically you need an NM [noise margin] value above zero after adding/subtracting gains/losses from your ant, splitters, etc, to receive a station. The only gain you'd add would be your antenna gain, not amps and such, you'd subtract all losses, such as splitters. etc.
It looks like WTAJ is right at the edge of what you'd possibly receive. Your ant. gain for UHF is 9.5 db, WTAJ's NM is -14.9, so still -5.3 NM and below zero before figuring losses for splitters, long cable run, etc.
You could look for a higher gain ant. but i think you'll only find ones a few db higher. When looking, if the db value is listed as dbi, then minus 2.15 from that to get the actual value in db. Example, my Winegard 8200u list the db gain as 14.9 dbi, so you'd minus 2.15, the actual gain in db for my ant. is 12.75 db.
If you can eliminate any splitters from your setup that will help, a splitters loss is usually anywhere from 2db to 4 or 5db. Your pre-amp should be only a few feet from your antenna if you don't have it there already, that way the pre-amp is helping to take care of all losses down the line rather than degrading the antenna signal through a long cable run, splitters, what not.
If you have more than one TV hooked to your antenna in the house use a distribution amplifier and not a splitter, I use a CM-3418 8-port. A splitter will lose you a few more db, where the dist. amp will work better and generally save a few db over using a splitter.
How high is the ant. mast that is on your rotor? I think 3 ft is the limit for most rotors, if it's higher than that you may want to cut it down or your new rotor may break too, especially with the wind load at forty feet. I have my ant. just a few feet above my rotor.
Like I mentioned earlier, ganging antennas may work, but then it may not, you may waste a bunch of money for nothing, and also the wind load on a forty foot tower would be something to consider there, especially the load of two antennas on a rotor. If you do try ganging antennas, then pay attention to the weight limit of the rotor that you buy. I receive stations out of NY here from over 100 miles away but I'm way high up on a hill with no major obstructions in between, quite different from your area.
It looks like WTAJ is right at the edge of what you'd possibly receive. Your ant. gain for UHF is 9.5 db, WTAJ's NM is -14.9, so still -5.3 NM and below zero before figuring losses for splitters, long cable run, etc.
You could look for a higher gain ant. but i think you'll only find ones a few db higher. When looking, if the db value is listed as dbi, then minus 2.15 from that to get the actual value in db. Example, my Winegard 8200u list the db gain as 14.9 dbi, so you'd minus 2.15, the actual gain in db for my ant. is 12.75 db.
If you can eliminate any splitters from your setup that will help, a splitters loss is usually anywhere from 2db to 4 or 5db. Your pre-amp should be only a few feet from your antenna if you don't have it there already, that way the pre-amp is helping to take care of all losses down the line rather than degrading the antenna signal through a long cable run, splitters, what not.
If you have more than one TV hooked to your antenna in the house use a distribution amplifier and not a splitter, I use a CM-3418 8-port. A splitter will lose you a few more db, where the dist. amp will work better and generally save a few db over using a splitter.
How high is the ant. mast that is on your rotor? I think 3 ft is the limit for most rotors, if it's higher than that you may want to cut it down or your new rotor may break too, especially with the wind load at forty feet. I have my ant. just a few feet above my rotor.
Like I mentioned earlier, ganging antennas may work, but then it may not, you may waste a bunch of money for nothing, and also the wind load on a forty foot tower would be something to consider there, especially the load of two antennas on a rotor. If you do try ganging antennas, then pay attention to the weight limit of the rotor that you buy. I receive stations out of NY here from over 100 miles away but I'm way high up on a hill with no major obstructions in between, quite different from your area.
Thanks for the info everybody...I guess It is as good as its gonna get...I do get wtaj also...as far as the rotator gos...the antenna is only about a foot above the rotator...I think its broke cause im on a hill with lots of wind...it broke during a thunderstorm wind gust that was the highest wind I seen here since I live here it lifte my trampoline up and move it like 10 ft so it was vary high wind.
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