# For the low voltage guys



## B4T (Feb 10, 2009)

You should call your CATV provider and ask tech support for their specs


----------



## leland (Dec 28, 2007)

Black4Truck said:


> You should call your CATV provider and ask tech support for their specs



Nice- just another give away our work answer!

No wonder the 'cable guy' feels so important.

I don't have a clue! try this.
My theory, don't work. try again.

http://www.radio-electronics.com/info/formulae/decibels/dBm_dBW_table.php

I'm a replace kinda guy- don't really care what broke in the board.
most times more cost effective to just replace than to trouble shoot/repair.
99% of sh*t now is disposable.


----------



## B4T (Feb 10, 2009)

He is up in Canada.. they have enough troubles already :laughing:


----------



## jamesclerie (Jun 2, 2009)

you should be around 0 db at the set top


----------



## cdnelectrician (Mar 14, 2008)

HAHAHAA call the cable company YEAH right LOL I know more about cable than most of the monkies do that they have working for them. They have actual "technicians" but try getting them to your house lol.

I worked as a CATV installer for a few months...never did any testing...just ran drops and dug holes lol


----------



## cdnelectrician (Mar 14, 2008)

jamesclerie said:


> you should be around 0 db at the set top


The channel in question (55) where they play all the good movies go figure...is snowy. I am getting +3.2 dbMV on channel 55 at the location in question and at the drop I am getting +19 dbMV.

So somewhere I am getting a loss...my toner won't tone through the cable so I am assuming that somewhere there is a splitter...maybe the cable in question is on the high loss leg of the splitter?

I was just wondering if anyone knew some guidelines for using this thing LOL I do remember being told to check levels on 2 of the lowest channels and then two of the highest channels. But I am not sure what they should be at exactly.


----------



## leland (Dec 28, 2007)

Black4Truck said:


> He is up in Canada.. they have enough troubles already :laughing:



I'm glad you took that as intended!!!!:thumbsup::thumbsup:

All in fun.


----------



## cdnelectrician (Mar 14, 2008)

Black4Truck said:


> He is up in Canada.. they have enough troubles already :laughing:


 
TROUBLE???? Where!!!!????







:jester:


----------



## Thayer (Sep 22, 2008)

~13 db is a lot of loss for a standard residential drop of appropriate lengh and cable type. Typically you expect 3.5+ db of loss per splitter depending on the model and 1-2 db of loss per 100" ft of rg-6 cable. Add up your situation and determine whether the situation the meter is displaying is consistent with the environment. If you cannot account for some loss, you may have a bad cable, connector, splitter, or other device. I wish I could help you more, but it is tough without being present.


----------



## cdnelectrician (Mar 14, 2008)

Thayer said:


> ~13 db is a lot of loss for a standard residential drop of appropriate lengh and cable type. Typically you expect 3.5+ db of loss per splitter depending on the model and 1-2 db of loss per 100" ft of rg-6 cable. Add up your situation and determine whether the situation the meter is displaying is consistent with the environment. If you cannot account for some loss, you may have a bad cable, connector, splitter, or other device. I wish I could help you more, but it is tough without being present.


 
My meter displays two levels, dbMV for sound and then dbMV for picture.

So I am assuming for the picture the ideal measurement will be 0db at the drop?

Here is a link to the meter I have...my version is a fair bit older than this one and does not measure digital signals, only analog.

http://www.comsonics.com/pdfs/WLD_spec.pdf


----------



## Thayer (Sep 22, 2008)

What you want to be looking at is the dbMv for the picture. The sound should be appropriately 8db or greater than the dbMv for the picture in a well balance system.


----------



## Toronto Sparky (Apr 12, 2009)

RG 6 and high freq splitters .
I just rewired my place  all is good now..


----------



## B4T (Feb 10, 2009)

Toronto Sparky said:


> RG 6 and high freq splitters .
> I just rewired my place  all is good now..


How do you tell a high frequency splitter from a regular one :blink:


----------



## cdnelectrician (Mar 14, 2008)

Thanks for all the input! I am starting to understand this now!


----------



## cdnelectrician (Mar 14, 2008)

Black4Truck said:


> How do you tell a high frequency splitter from a regular one :blink:


 
A high frequency splitter will be marked 1000MHZ or higher I do believe.


----------



## hbiss (Mar 1, 2008)

_Nice- just another give away our work answer!_

Hate to tell you but this ain't your work. If you are an EC your work is making receptacles and lights work NOT cable TV. Just looking at all your answers here not one of you has a clue. :no:

I will give you a hint though. If you have +3.2 at your set on CH2 and you have snow on CH2 it isn't the signal level. So either your meter is a POS or you don't know how to use it and it's really not +3.2 or you TV is the problem. 

-Hal


----------



## B4T (Feb 10, 2009)

hbiss said:


> _Nice- just another give away our work answer!_
> 
> Hate to tell you but this ain't your work. If you are an EC your work is making receptacles and lights work NOT cable TV. Just looking at all your answers here not one of you has a clue. :no:
> 
> ...


Hate to break it to you, but you can tell it to someone who cares.. I don't 

I will continue to run CATV and look like I know what I am doing :laughing:


----------



## steelersman (Mar 15, 2009)

There is a nail or staple in the cable somewhere.


----------



## cdnelectrician (Mar 14, 2008)

hbiss said:


> _Nice- just another give away our work answer!_
> 
> Hate to tell you but this ain't your work. If you are an EC your work is making receptacles and lights work NOT cable TV. Just looking at all your answers here not one of you has a clue. :no:
> 
> ...


 
Well, there is no harm in learning something new is there? Not like I am going to burn a house down while working on a TV cable. And, it IS becoming an EC's job to know this stuff these days. Sorry!

BTW I am not an EC.


----------



## hbiss (Mar 1, 2008)

If you are not an EC why the hell are you here asking a bunch of sparkies about something they have no idea about? If you have some background in cable and think you have the smarts to learn something that isn't as simple as these guys think sign up over here http://forums.cabletechs.org/index.php and get your answers from the people who do this for a living. 

-Hal


----------



## Thayer (Sep 22, 2008)

cdnelectrician, I did not fully read your post the first time. I thought you were just trying to understand how to use the meter. As Hal somewhat rudely pointed out, if you have +3 db at the jack, it is most likely that either your measurement is inaccurate for one reason or another, or something is wrong with the TV. Can you give me anymore information about your meter?


----------



## cdnelectrician (Mar 14, 2008)

hbiss said:


> If you are not an EC why the hell are you here asking a bunch of sparkies about something they have no idea about? If you have some background in cable and think you have the smarts to learn something that isn't as simple as these guys think sign up over here http://forums.cabletechs.org/index.php and get your answers from the people who do this for a living.
> 
> -Hal


No need to get excited bud. Some electricians know more about certain things than you would like to think. And no it isn't simple at all, I find it interesting and always have. Not interested in installing cable TV for a living or taking away your work...I would just like to be a little more informed on the subject.:thumbup:


----------



## cdnelectrician (Mar 14, 2008)

Thayer said:


> cdnelectrician, I did not fully read your post the first time. I thought you were just trying to understand how to use the meter. As Hal somewhat rudely pointed out, if you have +3 db at the jack, it is most likely that either your measurement is inaccurate for one reason or another, or something is wrong with the TV. Can you give me anymore information about your meter?


 
Thanks for your response! The meter I have can be seen here:

http://www.comsonics.com/pdfs/WLD_spec.pdf


----------



## Thayer (Sep 22, 2008)

I'm not terribly familiar with that particular model, but it should work just fine. Just make sure that it is set for the appropriate channel plan for your area. Otherwise it should work.


----------



## hbiss (Mar 1, 2008)

_Not interested in installing cable TV for a living or taking away your work...I would just like to be a little more informed on the subject._

Well, I haven't worked for a cable company in a long time so you aren't taking work away. About the only way to be more informed is to actually work with somebody who is in the industry. That link I gave you could help you also. Cable work is something that takes just as much of a commitment, time and education as becoming an EC. 

As for your meter, the reason you probably got it for nearly nothing is because it's analog and is pretty much useless now so cable companies are throwing them away. But if you are sure that your channel 2 is still analog it should make accurate measurements assuming it is good. Keep in mind that if you are using a cable box the channel 2 it displays could be on any frequency. 

-Hal


----------



## Thayer (Sep 22, 2008)

Nevermind


----------



## cdnelectrician (Mar 14, 2008)

I am sorry I forgot to add that my meter does analog only...and yes I suppose that is why I got it for free! It is the older version of the installer lite meter. I can't find a link for it, I guess there is a good reason for that!

The whole reason I dug this thing out in the first place was just to figure out why channel 55 is snowy on my dad's TV. He has run of the mill analog cable, I installed a drop amp I had kicking around and replaced the connectors with T&B snap and seals and the problem seems to have gone away. In the summer when I gut his basement I'll rewire the house.


----------



## Thayer (Sep 22, 2008)

Sounds good. Its amazing how cheap outdated technology can be! Glad you were able to solve the problem.


----------

