Determining the correct, unlabelled drop?
Many of you probably already know this answer without being asked. Intuition, experience, common sense, any number of variables will have you arrive at the answer without me writing this post. However, there is a few that possibly have never run across this, and when it happens, the only route to the answer might be the long route.
You arrive at your address, a brand new buried subdivision, first customer to be hooked up, you go to the pedestal, remove the lid, and inside, almost looking up at you are 8 unlabelled cables. Rolling your eyes heavenward at the ineptitude of the people laying these cables you reach for your cable toner, and recall with horror that the battery is dead in it, (now who is ineptitude, as we all make mistakes). Here we go, hook up a cable to the tap, go to the house, check signal, no signal, go back to the tap, hook up a second cable, go to the house, again, no signal. This might take you eight trips before you determine the correct cable. There has got to be a better way.
My little trick following will get you the correct cable in no more than three trips back and forth to the house and the tap. As I said earlier, this is likely redundant for many of you, but for a few, it will help save some time.
Assumption here: There is no fault in the cables, (brand new area and all, though not always an accurate statement).
- Step one; activate 4 cables through a 4 way splitter.
- Step two, check signal at the side of the house.
- Is it active, yes or no
- If it is active, it is in the group of 4 cables hooked up
- If it is not active, it is in the group of 4 cables not hooked up
- Step three, utilizing the set of 4 known cables, activate 2 of them
- Step four, check signal at the side of the house
- Is it active, yes or no
- If it is active, it is in the group of 2 cables hooked up
- If it is not active, it is in the group of 2 cables not hooked up
- Step five, utilizing the set of (now) 2 known cables, activate 1 of them
- Step six, check signal at the side of the house
- Is it active, yes or no…you now know which cable is the correct one?
- Step 8, complete proper prepping of the cable, labeling, proper connectorization, weatherproofing, proper torque, continue with job.
Just a fun little brain teaser of a problem that could help out in a similar situation.
Thanks all, and have a great day…Enjoy what you do, and you’ll never work another day in your life.
Live life to the fullest with no regret, as Tomorrow isn't guaranteed.
9 年I always use a cable toner and know my exact cable all the time.
School Administrator at CATV Training Institute
9 年Great Article Bob!
HFC & FTTx Specialist
9 年I always carried a test cable on a reel, about 250 feet long. I'd hook one end to the drop at the house, unreal the cable back to the tap and connect my meter to it. Connect one line at a time, until signal appears... there's your line! And tested for loss at the same time. I had the test cable's losses written on the reel for reference.
Failures, repeated failures, are finger posts on the road to achievement. One fails forward toward success. C. S. Lewis Do the next right thing. Elisabeth Elliot
9 年Another method is to attach an f-81 and a 75ohm terminator to the end of the drop at the house and use your voltimeter to find the cable in the pedestal by placing one test lead to your center conductor and the other on the outside of the f connector. Switch your meter to ohms and you should find the cable registering near 75ohms in no time!