i'm looking for some knowledge on combining 2 antenna's. If you see my post above once NYC gets its act together with the combiner, I should be able to get pretty much everything from Philly -OR- NYC on a single antenna just fine. But I would like to get both- having a tivo i cant predict which way to aim and might even need both directions at the same time - a rotator isnt really an option so I need to combine 2 antenna's. I'm hoping someone has a little insight before i try 110 trial and error steps.
A pile of questions.....
I'm not really in a situation to combine a 2nd antenna for just one channel like the jointenna's do rather I need to wholesale combine like 8-10 channels from one antenna with 8-10 from another. I've read and/or posted to the NYC thread, the Philly thread, and the central NJ thread but haven't gotten much luck yet- although have gotten some replies that make me think its very possible- but no one has tried to get all the possible channels to work at once and it doenst seem impossible to me from a technical perspective. I pass my local cable office occasionally and they have all kinds of antennas aon a tower that look like plain old radio shcak specials aiming all over the place- they must combine then somehow?
I do have an issue with an analog channel from NYC killing a digital from Philly so i almost definately need to get a notch filter for channel 31. Once idea i had was to get a jointenna to add channel 31 to the NYC feed- but just don't add it so that 31 would get stripped from the NYC antenna and then combine after the jointenna. I'm also wondering if in a perfect world would it be best to get a bunch of notches and just kill off the unneeded frequencies on each cable before the diplexor. But looking around i cant seem to find any easy way to do that- the jointennas really don't seem well suited to such a plan. I searched and searched and found this site that says i can basically cut a length of cable that dead ends to a tee to kill off unneeded frequencies- i was thinking of maybe adding a 5 way splitter and using the 3 unused tees to kill off the 3 channels that would be best to kill. Is that necessary or overkill? http://www.homewiringandmore.com/int...utions.html#20
Searching around I find a few references to kits used to steal cable tv where you can built your own notch filters to kill certain blocking signals for like $15 and I would do that but it seems the kits only work up to channel 22 and since i'm all over the UHF band that wouldn't help me much- got an email into the people that make the 'educational kits' to see if they have different parts for killing off UHF in the spaces between 22 and 69.
I am also a little confused about the whole same length cable issue. Seems the mantra is to make sure both antennas have the same length cable before the combiner but then then i read that was only relevant for multipath- however i think i am in pretty much perfect luck to that since my antennas aim almost opposite directions but not quite180 and i can use the aluminum siding from the side of the attic to block the rear's so each antenna really only will pick up where it is aimed. I tried combining but didn't exactly get stellar results- i tried with with same length cables and without- so not sure if thats an issue. And for the record what exactly is "same length" can i trust 2 '3 foot cables' from rat shack or does an extra milimeter that wasnt clipped oft he center conductor on one cable going to ruin the whole thing. Also the only way I can think to really get teh exact same lenght is to have 2 indentical antenna's - where do i measure from on a CM4228 versus the silver senor for example- or do I need to just get 2 of the SS's or 4228's? Any thoughts about the whole same length issue? What happens if i start adding in nothc filters- how to a calculate lengths?
Next I thought the combiner i use might be an issue- i first tried it with a splitter that Bellatlantic used on my Brother in Laws house years ago when they installed Directv to split the OTA analog antenna so I thought that would be high quality (long story there) . But then I read a splitter isn't exactly the same as a splitter/combiner. So I picked one up a radio shack that says 'splitter/combiner' and plan to use that- maybe i'll get better results. Any idea what to look for there- radio shack has like 4-5 choices so i just got the most expensive. Then I see at werner electronics that cm makes a combiner- do I need that? I've read that by combing the 2 antennas I will wind up transmitting some of the philly power out of the NYC antenna and vice-versa. Is there something like a diode that you can put in the combiner to stop the signal from backtracking up the other leg?
I'm just fiddling around now- an hour or 2 here and there but once NYC gets the combiner done and I have lots of choices in both directions i hope to be able to figure this all out.
I've searched around here and all over the web and theres lots of info about combining 2 or more antennas to get one source but i can find anything really except join-tennas to get 2 different sources. Not afriad to read so if you have links fire away