stacking 2 91xg what combiner to use

[joshg0207]

I currently have one 91xg and are vary happy with the performance. ..but I want to stack another one and was wondering what the best combiner would be to use to combine the signals from both antennas

[GroundUrMast]

Are you going to aim both at the same station(s), or are the antennas going to be aiming for separate signals?

If aimed at the same signal(s), simply use a reversed splitter such as the Ideal # 85-132.

If you are trying to receive signals from two different directions, please post a link to your current TV Fool report.

[joshg0207]

I was gonna aim them at the same signal...was also wondering if I would get enough gain to notice a difference anybody out there with experience in stacking 91xgs

[ADTech]

At best, you'll achieve about a 2 to 2.5 dB increase of gain on one channel in a perfectly executed antenna stack. You will also narrow the beamwidth to about half of the original in the plane of the stack.

If your reception is on the ragged, bleeding edge, then stacking the antennas will make a slight difference, perhaps enough to justify the exercise, perhaps not.

Use identical-length sections of coax between each antenna and the reversed splitter.

[Stereocraig]

Originally Posted by ADTech

At best, you'll achieve about a 2 to 2.5 dB increase of gain on one channel in a perfectly executed antenna stack. You will also narrow the beamwidth to about half of the original in the plane of the stack.

If your reception is on the ragged, bleeding edge, then stacking the antennas will make a slight difference, perhaps enough to justify the exercise, perhaps not.

Use identical-length sections of coax between each antenna and the reversed splitter.

Are there any spacing guidelines for ganging, or should they be as close as the reflectors allow?

[Tower Guy]

Try this: www.hdtvprimer.com/antennas/ganging.html

[Damon459]

Ok I know you guy's have covered this but I have a question. I'm using two AntennaCraft Y10-7-13's and a jointenna set for channel 11. Here's the issue with the insertion loss of the jointenna channel 11 barely comes in at all. I tried aiming then in the exact same direction and I get signal but it's unwatchable. So I emailed Antennacraft and told me the minimum distance between antennas should be 1/2 wave length or 32 inches, I went a full wave length or 64 inches. Now he mentioned something I don't understand in the lingo, he said "The most efficient way to stack this type of antenna is to run parallel lines (or 300 ohm twin-lead) between the two antennas and feed from the midpoint. Doing so, eliminates the loss introduced by the antenna coupler." what does this mean? I will tell you might setup is as follows, antenna at top of the pole and antenna at near bottom of pole with jointenna in the middle connecting two identical pieces of RG6 dual shielded. The out to tv line then goes down to an RCV tv Preamp on the VHF side. From there it goes around me trailer to the opposite side. I had to do this because the antenna just won't lock a signal on the other side of the house (odd I think but there you are). I also want to add a splitter so I can feed another tv in my guest room. Please go easy on me I'm still a newbie on all this ota stuff. Oh and I should add I need the preamp because I'm running all this to a 4 turner tivo roamio. Here is my tv fool report. http://www.tvfool.com/?option=com_wr...46aeda0dd01005 I'm getting KPAX-DT without issue, I'm trying to get KUFM-TV to also work hence the two antenna's.

[ADTech]

See this 1975 article by one of Winegard's engineers back in the day: http://www.kyes.com/antenna/stackluge.html

If you can receive that channel when not using the Jointenna, you'd likely do best to invest in a better signal combiner instead of stacking antennas to try an make up for an inefficient combiner.

You do realize you're right on the on the back side of a 2000' chunk of rock, don't you? Very, very little signal will actually make it down to your elevation and what does will be seriously compromised.

[Damon459]

Originally Posted by ADTech

See this 1975 article by one of Winegard's engineers back in the day: http://www.kyes.com/antenna/stackluge.html

If you can receive that channel when not using the Jointenna, you'd likely do best to invest in a better signal combiner instead of stacking antennas to try an make up for an inefficient combiner.

You do realize you're right on the on the back side of a 2000' chunk of rock, don't you? Very, very little signal will actually make it down to your elevation and what does will be seriously compromised.

Um yeah I know where I live thanks, sorry don't mean to seem like an ass but KPAX comes in with a signal level of 70 on my tv's signal meter because I point one of my antenna's directly at that mountain. The signal is very reliable year round, I installed the first antennacraft last year around this time and if even came in strong during blizzards. KUFM seems to "move" as much as 5 degree's depending on the time of year, and I was told on a another thread to try a second antenna for a stronger signal. I was also told I would need a channel master jointenna because the antennas are not pointed in the exact same direction most of the time. When I do get PBS the signal is about 40 but when it's at 40 it comes in perfect and never breaks up, if it drops to say 37-38 the picture will occasionally break up. I have read the article you posted but I don't exactly understand it hence my posting here asking if someone can explain it in way I can understand seeing as I'm not an engineer. As for a better signal combiner I'm open to suggestions for one that will handle two VHF antennas. Since the one I have now say's an insertion loss of 2.5 for channel 11. Oh and before someone recommends an A/B switch I tried this but with said switch I can't record PBS, IE I could just hook it directly to the tv and the other line to the tivo and get a good picture without the ability to record PBS.