ECN Forum Forums General Topics of the Trade Voice - Data - Video Discussion inexpensive coax tester

A splitter in the attic is not such a big deal to me as long as it's close enough to the hatch that I can get to it without going into the attic (or there are pull-down attic stairs and a floor).

Why do you want to do things the right way, an electricans first pirority is figure how cheap and fast it can be done!

I certainly hope you are trying to be funny.

-Hal

There are often many ways to do it "right." The best solution is always going to be a compromise between cost, practicality and efficiency. Safety should never be compromised. (At least, up to a point... I mean, we don't need #10 on 15A AFCI/GFCI breakers, dedicated to each receptacle in a house. Which, I guess, means we do compromise safety?)

Besides, cheaper install means less to mark up! Twice the cost=twice the profit! What kind of electrician are you, trying to save the customer money??

I'm hoping the same thing.

Ian A.

I sometimes use my little Darkstar D230 CATV tester for that type of situation. It can only determine if it is connected to an active CATV line, 50 Ohm terminated, shorted, or open line. It doesn’t offer any actual signal quality [SAM] measurements. Unfortunately, I just did a Google search and found that it is no longer in production. Maybe you can still find a good used one on ebay. I think it was only around $69.00 new, about six years ago.

Another unit I have that I know is still available, but is not as simple and straightforward to use, is the Progressive Electronics/Tempo CATV 402K tone test set. It looks like an ordinary toner/tracer, but can send signal through splitters, terminators, ground blocks, traps, etc, and can be direct coupled to an f-fitting. You can see if the line is open, shorted, or live by looking at the color change of the LED indicator. This kit is kind of expensive at about $175.00, but you can get double duty out of it by also using it for your regular toning and tracing.

For years, I’ve seen those little L-shaped Go-No-Go testers that another poster mentioned, but never managed to get around to trying one. That could be the most inexpensive solution. I think Specialized Products carries something similar.

I probably shouldn’t even mention this, but just in case some old Cable Dog tells you about it on the down low, I wouldn’t recommend using the idiotic and infamous “Taste Test”, that a few bone heads I used to work with a long time showed me. I can only describe it as like sticking a 9V battery in your mouth. Not to bright of an idea. If there is a problem with the neutral or grounding at the building, or a voltage spike somewhere in the system, it may be the last thing you ever taste.

It’s been quite a while since I’ve done it, but now that I’m thinking about it, I believe the second method I mentioned concerning use of the 402K kit, only works if there is a cable box connected and powered up for the line being tested. As I recall, the 402K indicated the active line from the DC voltage of the cable box output.

Don't you guys think in terms of db loss/gain when working with RF systems?

...the 402K kit, only works if there is a cable box connected and powered up for the line being tested. As I recall, the 402K indicated the active line from the DC voltage of the cable box output.

That's completely wrong. The 402K is simply a toner and probe. The CATV version toner has a cable and "F" connector. Like many toners it can also be used as a continuity and voltage tester. It has LEDs that will indicate when it is connected to a short, DC voltage or line voltage. No way can it tell you if there is a signal on the cable.

By the way, a cable box does not have any kind of voltage on it's output (or input for that matter). It's probably a dead short to DC as are most splitters. That's probably what your 402 toner is showing- a short. If the toner is connected into a splitter that presents a short it is unlikely that you will be able to pick up it's tone with the probe on any cable coming off of it. It's the same situation as trying to tone any shorted cable.

Trumpy, the original question was only how to identify which end of a cut cable is the feed. You are right, there is lots more that comes into play and if that was understood they wouldn't be cutting into a cable to install a splitter to begin with.

-Hal

Hal,
Then how would you explain this?
When I did CATV installs and post wiring of MDU’s back in the early 1990’s, although it was potentially dangerous, a very common way for some techs to locate a disconnected drop was to connect the cable box at the premises, then find the drop in the pedestal or lockbox by “tasting” the cable ends on the tip of their tongue one at a time. The DC would tingle on your tongue similar to a 9-volt battery. This “test” was only possible with a CATV box connected to the line and powered up, It would work for single family residences or even apartment buildings where the lockbox was located many floors below in the parking garage. I hate to admit it, but I did this my self when time was a factor.

AC leakage from the hot or neutral of the line cord to the box housing or chassis for sure. There are always at least caps from both sides of the line cord to the chassis ground. The chassis of course holds the "F" connectors so it is connected to the shields. I'm not sure if there is also a difference of potential between the shield and center conductor or he was picking up a tingle because he was standing on soil or concrete, but that is the cause.

-Hal