This may be a stupid question but I haven't been able to come up witha solid yes or no answer fromk my searching of the forums.

I will be running wire this weekend through the attic and walls of my new place for data, voice, ota and satellite. these will all be terminated in a 6 keystone wall plate behind my entertaimnment center.

I bought 3 keystone f-connectors for the 2 sat feeds and the 1 ota feed. However I am starting to think that the angle is to much for the cable in the wall. So my thinking is that i should put 3 90 degree coax connectors on the backs of the keystones. this would allow the three coax lines coming from the attic to drop straight down the inside of the wall with no crazy bends.

So basically the cable would go from the sat -> attic -> wall -> 90* connector -> f-connector keystone -> cable -> Satellite receiver.

but here is where I need some clarification. I read all over that "digital is digital." So my question is if this is true, then i shouldn't have to worry about any signal degredation or loss by adding these connectors right? i could just go pick up 3 of these from rat shack:
http://www.radioshack.com/product/index.jsp?productId=2102529

In no way will adding these connectors hinder the signal coming from my satellite and ota antena?

And does that mean i can screw in a few of my coax cables I have had since the early 80's and there will be no signal loss either? That makes no sense. Surely some cables are better than others.

I guess in the end, i just want to make sure that if i put some 90* adapter/connecters on the back of those keystones, i won't have any issues with my hd quality coming in.

Thanks and sorry for the long ramble.

I have seen reference to an insertion loss of 0.15dB per connection for high grade "F" connectors. So you would have 2 connections to the keystone and a 3rd connection at the back of the 90 degree connector or almost .5dB loss at the total "wall connection" The more connections, the more loss.

Your 1980's coax is probably older RG59 75 ohm coax. It should be replaced with high grade RG6 or Quad shield RG6 that meets the requirements of the satellite company. Usually this is coax that has been certified as sweep tested to 3Ghz. The most loss in your entire system will be in the runs of coax from the dish/antenna to your TV

However I am starting to think that the angle is to much for the cable in the wall. So my thinking is that i should put 3 90 degree coax connectors on the backs of the keystones. this would allow the three coax lines coming from the attic to drop straight down the inside of the wall with no crazy bends.

Good idea. The smallest bend radius is typically about 3" for coax, so there is space within the 3.5" stud width if you choose not to use them. The use of right-angle connectors is usually not used because of cost. The signal loss is usually not a concern. I have enough signal strength from a high-gain antenna that there are a splitter, a couple of right-angle connectors plus a push-on converter in the signal path.


I read all over that "digital is digital." So my question is if this is true, then i shouldn't have to worry about any signal degradation or loss by adding these connectors right?

Maybe people say that, but then ask them to explain the difference between "analog" and "digital" signals.

Actually the coax cable in this case is carrying RF (radio frequency) signals. The cable does not know/care if the modulated information is analog or digital. This RF signal can be degraded and/or attenuated to the point it is unusable. So concerning yourself with signal loss and degradation is legitimate. For instance, be careful when you handle the coax: do not kink it or compress it or pull too hard on it. It is rather delicate cable, and should not be treated like rope although there is a resemblance.

Regards

P.S. If you want to use a low-loss, high-quality RG-6 coax, then look into Belden 1694a. Considered overkill for TV antenna connections, but copper was still cheap when I bought it (i.e. 30 cents per foot).
http://www.bluejeanscable.com/pages/technicaldocs/1694tech.htm

you want to use a low-loss, high-quality RG-6 coax, then look into Belden 1694a. Considered overkill for TV antenna connections
Copper is overkill for any RF application. Read up on the 'skin effect' and you'll see why a standard CATV coax center wire has just a thin copper layer on a steel core. http://en.wikipedia.org/wiki/Skin_effect

The use of right-angle connectors is usually not used because of cost.

The connectors I have seen are from about $1-$5 per. I must be looking at the wrong ones then.

An alternative to wall jacks is to bring the cable straight through. Depends on the ugly factor and connector loss and cable stiffness, you decide the issues important to you. You can always put jacks in place later if wanted to please spouse or sell house.

Use 3.5 inch deep boxes to get full depth of wall for bend. Get a solid coverplate
and drill holes to pass cables, make large enough to fit rubber grommets to use those. Bring cables through to the length desired and make the ends.

As has been written previously, you should have no problem whatsoever. There is plenty of room in standard walls. If you do decide you need some, there are some here (http://www.cencom94.com/gpage1.html). About 1/2 way down on the right-hand side (F90-HR).

Most of the info posted went over my head. or maybe it's hard to think cause I've been up since 3 with the baby. but the jist seams to be that therre will be some signal loss from using the 90 Degree connectors to the keystones. But the signal loss is not enough to notice or maybe it is.

Thinking about this further I realize i am going to be using the directv installers cable up to my keystones. So I am going to assume that this is some pretty stiff stuff.

I am also guessing that I will have to have some 90 Degree connectors on these based solely on stiffness.

i'm lost, but gonna give it a try anyways. going into the attic for the first time today to see what i am looking at for a run.

Copper is overkill for any RF application. Read up on the 'skin effect' and you'll see why a standard CATV coax center wire has just a thin copper layer on a steel core.

Hi there

Presumably you meant "solid copper center conductor" versus the typical copper-clad steel center. You still need copper for low resistance.
Belden 1694a has a lot more copper than just the center conductor; the braid shield is also copper.

The typical CATV company uses miles and miles of coax. They will use the cheapest cable that meets their spec. Hence copper-clad steel conductor. That's good enough for CATV, but that doesn't mean you have to use it for an antenna installation.


The connectors I have seen are from about $1-$5 per. I must be looking at the wrong ones then.
I was thinking of the professional installer's perspective: why spend the inventory, installation labor and material cost when a few seconds performing the bend will accomplish the same thing?


Use 3.5 inch deep boxes to get full depth of wall for bend.
The building code probably does not require an electrical box for TV and phone outlets. Use a "low-voltage box" or just cut the back off the plastic box. You don't want to deform the coax when threading it through the plastic box inlet.

Presumably you meant "solid copper center conductor" versus the typical copper-clad steel center. You still need copper for low resistance.
Belden 1694a has a lot more copper than just the center conductor; the braid shield is also copper.
No, I meant for RF any more than a couple microns of copper is a waste. Unless you're carrying power on it too. Video cable (such as Belden 1694a which is typically used in wiring TV production gear) needs to carry low frequencies (dc to several MHz) and benefits from copper. RF (anything above a few MHz) is subject to the skin effect. As far as shielding goes, much more important than the material used is the amount of coverage. Again, the loop resistance of the cable only enters into the picture if you plan on carrying more than a few milliamps of current on it too.