Extra coax run?

[kenyarnall]

My setup used to be: One 500 on the roof, one 721 in the den. There were two coax cables run from the dish to the 721.

I just upgraded, and the tech installed a second 500 to point at 61.5. He ran a cable from that dish to the other one (I haven't looked closely to see how the connection is organized). I noticed after he left that one of the two coax cables running from the dish to my house seems to no longer be in use; it is still connected to the dish, but not to my VIP722 --- one of the cables is connected to some sort of switch or splitter, which then connects to both tuner inputs on the DVR. The tech just left the other cable sitting loose behind the DVR.

Here's my question: Am I right that both of the cables from the dishes to the house carry the same signal, and that if I have but one receiver, I can disconnect the other one? I'd like to use that cable for a OTA antenna, since it's already run into the house. If it doesn't do any harm to disconnect it from the dish (how could it, since it doesn't feed anything?), that is.

Just making sure I'm not missing anything.
Ken

[BattleZone]

You're exactly correct. A DishProPLUS dual-tuner receiver can be fed with a single cable when connected to a DPPLUS LNB or switch. A DPP Separator is used at the receiver to split the single line to feed the two tuners. Thus, your extra line is now redundant and can safely be retasked for off-air or whatever else you need.

[kenyarnall]

You're exactly correct. A DishProPLUS dual-tuner receiver can be fed with a single cable when connected to a DPPLUS LNB or switch. A DPP Separator is used at the receiver to split the single line to feed the two tuners. Thus, your extra line is now redundant and can safely be retasked for off-air or whatever else you need.

Thanks! Since posting I followed the EKB link and discovered lots of good info on the hardware and how it is to be connected. I have a clear picture in my head of how the setup is organized, and why the cable was no longer required (and, more to the point, why it was required before; that change is really what had me confused).

Thanks for the confirmation.

[kenyarnall]

Well, I put the antenna up, no problems. I have one additional question, though, for those who know.

The second coax cable (the one I nabbed from the dish for the antenna) is connected to a grounding strap which is hanging from the dish. Is there any reason not to reuse this grounding strap for my antenna cable? As I currently have it wired, the grounding strap has the cable carrying the dish signals, and the cable carrying the OTA antenna signals, connected to it. This keeps me from needing to run an additional ground wire.

Is there any reason this would not be OK?

Also, the antenna is on top of a 10' mast; should I ground the mast as well? If so, is it OK to strip the existing ground wire and connect it to the mast (about 5 feet downstream from the sat dish)?

Thanks,
Ken

[BattleZone]

...a grounding strap which is hanging from the dish.

Not quite sure what you mean by this... Normally grounding straps are used to provide a bonding location to a pipe, and aren't normally used at the dish.

Your dish should be grounded either via a 10 gauge green-insulated solid copper wire, or by a 17 gauge solid copper "messenger" wire that is bonded to the coax cable. One end of the ground wire should be attached to the dish, and it should run down with the coax to a ground block, which the coax should also run through. A 10 gauge green solid-copper wire should run from the ground block to a ground source on the house, preferably to the house's ground rod, to the wires connecting the ground rod to the power meter, or to the meter housing itself.

There would be no problem disconnecting one of the coaxes running to the dish and using it for your off-air antenna. Your antenna should also be grounded. Ideally, this should be a separate 10 gauge solid-copper ground wire running down to the house ground, but daisy-chaining to the dish is better than no ground at all.

[kenyarnall]

Not quite sure what you mean by this... Normally grounding straps are used to provide a bonding location to a pipe, and aren't normally used at the dish.

It's a grounding block, like the one I bought at RS. You screw the coax into it and run a ground wire from it to the grounding rod in the earth. The one on the satellite dish has couplers for two coax cable connections. I can attach my antenna to this, and then the original cable runs from there to the house, and the connection is grounded.

Your dish should be grounded either via a 10 gauge green-insulated solid copper wire, or by a 17 gauge solid copper "messenger" wire that is bonded to the coax cable. One end of the ground wire should be attached to the dish, and it should run down with the coax to a ground block, which the coax should also run through. A 10 gauge green solid-copper wire should run from the ground block to a ground source on the house, preferably to the house's ground rod, to the wires connecting the ground rod to the power meter, or to the meter housing itself.

The dish is grounded by a green copper wire running from the dish to the grounding rod. The coax is grounded by the same wire, running from the grounding block. This is the wire I want to piggyback onto.

There would be no problem disconnecting one of the coaxes running to the dish and using it for your off-air antenna. Your antenna should also be grounded. Ideally, this should be a separate 10 gauge solid-copper ground wire running down to the house ground, but daisy-chaining to the dish is better than no ground at all.

My real question, I guess, is whether it's OK to ground my antenna mast using the same wire that's grounding my sat dish, or must I run a second wire to handle that?

[BattleZone]

If it was me, I'd go ahead and just daisy-chain a ground from the antenna to the ground block. And, yes, running the coax to that ground block is fine.