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Common problem: Drop verification

Started by Helter, July 08, 2008, 07:26:10 pm

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Helter

Directions: it is an estimate only, you should verify any calculations by hand before using as a method to verify drop integrity.

I now have static values from our cable supplier, TFC for everything no more theoretical estimates.

Once there, there are 2 tabs that calculate things.

Signal Calculations take readings at tap enter in Starting point signal column, estimate drop distance, it will give you an estimate of what you should find at the ground block [you could also use this for calculating the loss on outlets etc but I will only explain drops.

So why can I enter multiple values like 100 foot for 59 and 11? In my FFO UG often goes to a flower pot or 2, the cable can change at these points often I find 11 under the road then 6 to the house for some reason when it should be 11 all the way IMHO. Getting this corrected depends on people higher up who often chose to SAVE the money. Yes you could shoot each piece, but most likely you will go TAP to GB, this allows you to account for this at houses you know well enough to know the set up. I pretty much change 59 on site, but some FFO's and companies do not, I am sure, so it is there too.

That said, this is probably not the tab you will want to use unless you just want to verify your own internal calculations.

Distance calculations: for this one, you will take your start [tap] signals and your end [Ground Block] signals and it will estimate the distance required for that much loss. You will estimate the distance you think the piece of cable is, and so this should be used loosely. For example, if my calculations show its 145 foot and I thought it was 125 feet I do not suggest putting in a BSR for this, either the tubing went a different route than I expected or I am just wrong. If I have an RG6 drop and the program says I am at 250 foot for my loss using the spread sheet and I estimate 150 foot visually, then it is Fault locate time.

At that point it is either a bad drop or it needs to be RG11, in either case I no longer care they need to fix it [course a temp RG6 drop to the house will help clarify this too]

These are just some examples of how to use this tool, your mileage and values may vary.
Cable dictionary
Masochism - Setting DSLR as your home page.
Sadism - Setting other cable tech's homepage as DSLR.

CableDaddy3

Quote from: dj4man on February 10, 2008, 03:14:22 pm
I feel like every day I worked as a contractor was a day stolen from me.

Quote from: CableTool on December 18, 2007, 01:53:02 pm
They have like.. yellow crumbely crap on em? And smell odd.
In any event, tonight Ill clean em up and give one a whirl...

http://adam-tech.blogspot.com/

widget

Quote from: Helter on July 08, 2008, 07:26:10 pm
removed, many errors on sheet, no time to fix them atm... studying for next advancement test, and  my daughter is becoming very time demanding.


Any plans on this coming back at some point? Or something similar?
Service & Maintenance Tech

Helter

Quote from: widget on November 06, 2009, 05:18:52 pm
Quote from: Helter on July 08, 2008, 07:26:10 pm
removed, many errors on sheet, no time to fix them atm... studying for next advancement test, and  my daughter is becoming very time demanding.


Any plans on this coming back at some point? Or something similar?


Kicking it around now, she is 2 and a little more willing to go play in her room and give daddy think time, though not much, leave her alone to long and she is surely up to no good. Probably going to skip the excel part and make it html perhaps, I don't know about your lap top but it takes 10 fn minutes to open excel on mine.
Cable dictionary
Masochism - Setting DSLR as your home page.
Sadism - Setting other cable tech's homepage as DSLR.

Helter

Quote from: widget on November 06, 2009, 05:18:52 pm

Any plans on this coming back at some point? Or something similar?


Fixed as a excel file for now some stuff removed due to inability to verify accuracy
and the signal loss chart was simplified by removing the double charts.



Cable dictionary
Masochism - Setting DSLR as your home page.
Sadism - Setting other cable tech's homepage as DSLR.

widget

Yeah kids are great, but a handfull for sure.  Spreadsheet looks great.  Wish i had of had this on friday haha.  rg6 at the tap and rg59 at the gb, underground in a totally beat out system.
Service & Maintenance Tech

RokitArmor

During training I had created a program for my TI-86ti that would calculate signal levels from tap to all split locations and outlets.  Just enter tap levels, drop type and length, passive design, and outlet type and length.  If your results are more than 2-3db off at any location you know you have a problem.  Really made life easy during the passive design testing part of class lol.
I'll see if I can scrounge it up, was pretty convinent considering a calculator is easy to transport.

steelhead78

We actually have a drop loss on the TRR Symbol Portal.  You enter the tap value and levels, drop length and type, also the return specs for your system, and it will give you drop levels at the side of house or equipment, plus your return levels.

I just remember approximate losses for different channels on 6.  Channel 2, 1.6 dB per 100', 116, 5.65 dB per 100', 30 MHz 1.2 dB per 100'.  59 has a little more loss, but I have about 3 different loss calculators in my truck if I need them.
Comcast- Blairsville, PA

This is like a think-tank of nothing.

widget

Quote from: RokitArmor on April 26, 2010, 11:33:42 am
During training I had created a program for my TI-86ti that would calculate signal levels from tap to all split locations and outlets.  Just enter tap levels, drop type and length, passive design, and outlet type and length.  If your results are more than 2-3db off at any location you know you have a problem.  Really made life easy during the passive design testing part of class lol.
I'll see if I can scrounge it up, was pretty convinent considering a calculator is easy to transport.


Let me know if you happen to find that, I would be very interested in it.
Service & Maintenance Tech

Helter

Version 7 completed, simplified it back to like I started [lol], added loop resistance check back in.
Cable dictionary
Masochism - Setting DSLR as your home page.
Sadism - Setting other cable tech's homepage as DSLR.

RokitArmor

Heh managed to find it.  Still a work in progress, run rfloss() and you should be able to play around from there.  So far I think i got it so you can add a drop, add tap and dmark- "dm" levels, and calculate how much your signal is off.    supposed to be a complete passive design calculator allowing you to add splitters and configure them.