View Full Version : Where to find uncommon switch
10-11-2011, 01:11 PM
Looking for a combiner-type switch for my OTA setup. I have 2 antennas, outdoors, and they are approximately 150' apart on two separate towers. Since most everything I want to see is available on UHF digital channels now, I Do not need the switches that I can find, which combine VHF+UHF signals, and only then if they are on the same mast or tower.
Both these UHF antennas are using amplifiers, as I live in the sticks, and work well, but I need to combine the two signals to send to other tvs in the house. Somebody must make a switch to combine two UHF sources together into one line-out.
10-11-2011, 03:40 PM
Easier said than done! You can buy something like a jointenna, to combine one channel with the others. But the technical problem is that two antennas separated by 150' will have phasing problems, at least on some of the channels. This happens when the same signal enters both antennas, but at the junction destructively interfere.
10-11-2011, 08:36 PM
Krell, thanks for reminding me of something BASIC! Doh, I should've remembered that, been studying the same concept lately, except with scanner antennas. Guess I was just thinking of the fact that since they are dissimilar antennas pointing in opposite directions from each other, they wouldn't clash electronically. Though I really don't understand why....suppose the only way to do this the way it might work, is the old A-B switch behind the tv, and just use 2 coax cables. Or build my own cable company , lol.
edit: To add, what I'm doing is trying to watch channels from two cities 90miles apart, and I'm in the middle of them. Neither use the same channels to broadcast . Would the phasing problem still be there in that case?
10-11-2011, 08:48 PM
You can try a simple splitter in reverse, but unless you are very lucky, the results will not be what you expect. The other way is to use filters to eliminate the signals from the unwanted direction antenna and then a spliter (in reverse) to join the resulting two feeds together. Gets expensive fast.
Tin Lee Electronics :: CATV Filters (http://www.tinlee.com/catv_filters.php?active=1)
Heres a good forum to start reading
Over-The-Air (OTA) Digital Television - Digital Forum (http://www.digitalhome.ca/forum/forumdisplay.php?f=81)
10-11-2011, 09:10 PM
Well... If the stations are very nearly 180 apart, and both antennas are very directional with a high front/back ratio, then you might get away with this using a simple splitter in reverse. That's so cheap I would try it and see how it works.
10-11-2011, 11:57 PM
I forgot to mention both these uhf antennas are running amplifiers, which complicates how switches work , power-passing or won't, etc. I will try the simple old splitter in reverse trick for grins, but I may have to settle on a 2 cable arrangment with a/b switches at the tvs after all. Tv surely gets complicated sometimes, lol, before digital it was always fighting the ghosting caused by 2 mountains.
Now I can get a decent signal on most channels within my range, but I need 3 antennas to get them all, with a couple south of me still being on vhf frequency channels. But those channels I can live without. I"ll post back when I come up with a working solution-I appreciate all the advice I received.