Can you splice or add a coupling to coax with out losing a bunch of signal?
This is a discussion on Can you splice or add a coupling to coax with out losing a bunch of signal? within the DTV | HDTV Reception and Antenna Discussion forums, part of the Over-the-Air (Antenna TV) category.
I have to extend my antenna now that we're doing some construction in our house and changing location for our TV. Is it possible to splice or connect a coupling to a coax wire without losing a ton of signal? I already have a preamp installed at the antenna. My worry is that the antenna is already far enough away from the TV at approx. 250' on a tower.
Since splicing involves just sticking two wires together to extend it, I'm pretty sure it would work fine. Longer cables will lose the potency of the signal slightly, but it's not really even noticeable, but I've not heard of it for lengths of 250 feet.
I'd just buy a ridiculously long cable or maybe a bunch of extensions. Since you have an amplifier, it should work just fine.
Welcome to the Forum Walt!
Originally Posted by TVWalt
Here is a quick way to figure it making a couple of assumptions.
1) You amp is 28 db of gain (guessing)
2) Your coax is RG6 (not RG59) (guessing)
NEW RG6 has a loss of about 6 db per 100 ft at ch 40
6 goes into 28 about 4.66, so a big amp will drive 466 ft of New RG6 that doesn't have any splitters or couplers in the path.
A 2 way splitter adds 3.5 db of loss and a coupler like you are needed is about 1 db of loss.
The best way to extend a cable is with a F-Fitting Barrel
RadioShack Gold Series F-Connector Coupler - RadioShack.com
It has female threads on both sides so you can just hook one cable to another.
Now that said if you know the model of your amp, type and age of coax, actual length of coax after the extension is added. Are there splitters in the house?
Is the amp actually up at the antenna?
Then I could do a very specific site report for you with that data.
Bare coax cables, without connectors, cannot be spliced together without causing serious signal loss. Cables with male F-connectors molded on to the ends at the factory may be extended by using a "barrel connector" that looks like this:
Barrel-connector "insertion loss" is so minimal that even most users without amplifiers won't notice the difference between an extended cable versus an outright replacement that has no inline connectors. It's really a non-issue in the presence of an amplifier. This is probably the easiest way to extend a coax cable.
If you wish to compress F-connectors onto the cable by hand, you need to make certain there's no contact between the outer shield and center conductor. Such contact is a short circuit that would kill all signals in a hurry. Most DIYers need to practice compressing connectors onto coaxial wire before working on the final installed cabling.
Oh, and lest we forget..
An F connector is approximately .20 db loss. I wouldn't effect the signal enough to calculate it in your system.
Yep, the amp is at the antenna. Thank you all for the f- connector idea. I'll try it first. I saw recommendations somewhere last week at another site for adding a distribution amp for a similar antenna move like mine but I'm going to try the f-connector first.
I have heard a perfect barrel is about 0.5 db total, but I round up to 1db depending on the condition of the barrel, how well the crimp or compression fitting was done.
Originally Posted by 1inxs
But if an f fitting is .2, then two of them are .4, plus what ever the barrel itself adds. So I think that fits in what I have read a perfectly done connection is 0.5 db.
If you were to add a distribution amp and your mast head amp is more than 12 to 15 db of gain, you will lose channels in overload.
Originally Posted by TVWalt
The worst thing you can do now with digital is gang two amps on the same line. The only time you can do it is if you engineer the gain of all your masthead amp, then loss due to coax..
Since we don't know the gain of your masthead, I would say stay away from distribution amps.