OTA Antenna setup question

[wkkb02]

Hey Guys,

Ok here's the deal... I bought a ChannelMaster Crossfire OTA antenna and have it at the top of a 20 foot mast. Now I have about 80 or so feet of RG6 that connects it to a 4way splitter. I have a 12db inline amplifier about 10 feet before it enters the splitter as well. The splitter then feeds 4 cables into 4 diplexers to combine it with my DishNetwork feeds that go to 4 different rooms. Now the house is wired with some poor quality cheap RG59. (damn those cheap bastard contractors... ) So I put diplexers at the end of the RG59 to once again seperate the OTA from the satellite signal. The problem I am having is that I am not getting any OTA signal whatsoever. I'm not more than 20-30 miles from most of the broadcasting towers and I've tried rotating the antenna but nothing... So is it possible that the RG59 is not adequate for carrying the two frequencies and maybe the satellite is somehow drowning out the OTA frequency feed. Because the satellite signal works perfectly. I can't think of anything else to try And I really dont want to rewire my house unless that is definitely the problem. Any Ideas?

Thanks!

Kris

 

[dturturro]

What type of inline amp are you using? The CM7777 is the preferred preamp by most people. Take the plunge and get new RG6 cable and eliminate all those diplexers too.

You should have:

The antenna feeding the preamp (shortest jumper possible) feeding the preamps power supply (inside the house). From the power supply to the splitter (as centrally located as possible) on to the receivers.

With those changes and the short distance to the transmitting towers you should be fine (provided you don't have any obstructions, like mountains or tall buildings, in between the towers and your antenna).

 

[wkkb02]

Actually it's a radioshack satellite inline amplifier with a 13db gain, 950-2050 MHz. (made in China... ) I would prefer to keep the diplexors to keep the amount of cable I have to run at a minimum since I'll have 4 room to deal with. Diplexors shouldn't be causing the problem should they? So you recomend I get the CM7777 and replace the RG59 in the walls? Guess i'll do that this weekend and see what happens. Thanks for the advice, I'll let ya know how it goes.

 

[dturturro]

Start with replacing the amp and NEVER buy anything from Rat Shack ever again. Next replace the RG59 with RG6. If you're still having problems after that you may have to by pass the diplexers. Remember, you lose signal with every device. So you're not only losing signal from the diplexer but the F-connectors as well. Of course that may only be a few dB anyway.

I just reread your post. Is the RG59 just from the diplexers to the receivers or from the switch to the diplexers?

 

[wkkb02]

Hahaha OK Radioshack is a "no-no" got it. Actually from the splitter there is only 6-8 inches of RG6 before it hits the diplexor. From there it's all RG59 up to the reciever. So its only the cable in the walls that really needs to be replaced. But again the satellite signal is crystal clear going through the same cables/diplexors/F-connectors. I'm just losing the OTA signal. I don't know the physics of these things, but is it possible that the capacity of the RG59 to conduct the freqeuncy of the satellite signal is insufficient to carry an OTA signal as well? I imagine the satellite frequency is somewhat higher than that of the OTA antenna feed and the OTA is just getting dropped? Again I don't know much about this so if I am just talking jiberish here, just ignore me haha .

Thanks.

 

[dturturro]

If you satellite LNB/switch is Dish Pro or higher than you're going to run into problems sooner or later. The Dish Pro equipment has a higher current draw and frequency range than RG59 can handle. Get yourself a DHA trouble call for $30 and tell the technician you periodically lose half your channels. That's a sure sign that you're losing the higher frequency transponders and they'll run new lines for you.

 

[wkkb02]

What is DHA? Besides $30 to have em come out will they charge any more to run new lines?

 

[dturturro]

DHA is Digital Home Advantage. It costs $5 a month, but if you have a trouble call (which you do) it only costs $30 instead of $100 and all costs are covered by the plan. The important part to stress is that you lose half your channels. Point out the old RG59 cable and a smart tech will realise your losing the higher frequency transponders. Someone on the board can probably narrow that down to specific channels for you. This is usually an intermittent problem as all kinds of things can affect the wire.

 

[wkkb02]

Ahh... yes haha! Actually that's funny because on occassion I do lose some channels, especialy Fox News and a few others. That might be it... I don't know if they'll cover my old RG59 cables with the "DHA" though since they didn't install them. And if I want them to fish all the walls they may charge quite a bit no? My CM7777 is due to arrive on Tuesday.

Kris

 

[dturturro]

Cable and wall fishing are all included. If they try to charge you extra they're lying.

 

[wkkb02]

OK so I think I've narrowed the problem down to the diplexers. Everything works well except for when I try and combine the signal with the diplexers and the OTA ends up getting dropped entirely but I get perfect satellite reception still. Maybe the diplexers I have are no good? Can you recomend some top of the line diplexers? So I hooked up the CM7777 with my CM Crossfire OTA antenna and I get 100% signal strength when connected right to the television (without diplexers) even after running it along nearly 250 feet of cable length haha. I know you said the diplexers aren't recomended but I think it will work if I just get some that actually work. I don't even know what brand these ones I have now are... I just bought 8 of em for like a dollar a piece off Ebay. So I'm thinking that was a bad investment. haha
What do you think?

Thanks

 

[dturturro]

All 8 are broken? That seems unlikely. Are they definately diplexers and not splitters? There should be 2 inputs (1 satellite & 1 antenna) and 1 combined output. After the splitter the jumpers from the splitter should be connected to the antenna port on the diplexer, the jumper from your satellite lnb/switch connects to the satellite port. The lines that run to your receivers get connected to the combined port of the diplexers on either end. Finally, the antenna port on the end diplexer goes to the antenna in port on your receiver/TV and the sat to the sat.

 

[wkkb02]

Yep that's how I am connecting them. I wonder if they are maybe all dual port rather than single port power passive diplexers. Because if they are the dual port they cannot be placed on the bottom end near the reciever right? But that would be hard to believe that I got dual port diplexers for so cheap right? *shrug*

 

[dturturro]

Can you take a picture of them?

 

[seesofar]

Could someone give me some advice? I have a CM4221 with a Spartan preamp (powered by my Dish 811) mounted just below the antenna feeding into a diplexer and diplexed again at the Dish 811. I'm getting 80-90% signal, but having dropouts on ABC, and CBS takes awhile to lock in at about 80%. Could I connect an ASKA AM-125 to the UHF between the indoor diplexer and the 811? Would this help my problem? I went with Antennaweb recommendations but I still can't get PBS without turning the antenna. All coax is RG6 about 125'. Any suggestions?