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Old 11-26-2013, 02:17 PM   #16
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How to check cable signal strength


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Originally Posted by gregzoll View Post
The reason they change the fittings on connections, is due to using Copper Clad Steel, and that there are tech's that do not know how to terminate them properly.

As for skin effect, it has nothing to do whether the cable is CCS or solid Copper core. Also RG-59 is only good for short distance patch cords, not for long runs through homes, also never ran from the pedestals or poles to the structure.
The center conductor has nothing to do with the fitting. CCS and solid copper use the same quarter quarter prep.

The center conductor does play a big role in the skin effect. Copper is more conductive than steel and therefore the RF will ride on the skin and flow easily to the contact points.

Tell me why you think 59 is such a bad thing to use in house.

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Old 11-26-2013, 04:05 PM   #17
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How to check cable signal strength


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Originally Posted by Tonglebeak View Post
The center conductor has nothing to do with the fitting. CCS and solid copper use the same quarter quarter prep.

The center conductor does play a big role in the skin effect. Copper is more conductive than steel and therefore the RF will ride on the skin and flow easily to the contact points.

Tell me why you think 59 is such a bad thing to use in house.
Keep telling more please. I can pull enough information to educate you, that you are way off on all of this. I will let you know that I have been around this stuff all of my life of 46 years, soon to be 47, along with my father is a retired E-7 from the Air Force as a Radioman. I also dealt with this stuff as a IC on my ship, when dealing with comm. cables between certain gear that we had, that used a digital signal for it.

I am sorry, but you are way off on what Skin effect is, and that you think CCS is better than Solid Core Copper RG-6.

DirecTV uses Solid core Copper for their RG-6, which is the stuff I posted the link to. RG-59u is only good for short jumpers, is not good for Digital television, or digital signal at all, due to its high loss. RG-59u is not even used for OTA antennas anymore, due to going with Digital transmission, there is too much loss & attenuation with it, which can cause pixeling, and drop-outs.

Skin effect for Coax, is completely different than Skin effect for electrical cables. Here is some information on what Skin Effect is. http://www.radio-electronics.com/inf.../coax_loss.php
http://bambus.iel.waw.pl/pliki/ogoln...L/252/01_a.pdf
http://iet-journals.org/archive/2012...1351593914.pdf
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Old 11-26-2013, 06:37 PM   #18
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How to check cable signal strength


I don't care if you emit RF out of your nose. Neither of those three links really helped you out. You also don't seem to understand that RF is not AC. RF flows along the skin of CCS much more readily because, surprise, the copper is the most conductive and is on the skin of the steel core..

When you lose 6.5db@750mhz per 100ft on 59, and 5.5db on 6, are you really trying to say that it's a big deal? Especially when we're talking residential. We're not talking about running miles of this stuff. Whether or not the signal is digital or analog does not matter either. If the shielding is good, then there's no worries. Just how much do you know about qam?
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Old 11-26-2013, 06:50 PM   #19
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How to check cable signal strength


Also, you keep talking about DirecTV. The op has Comcast. Do you know why DirecTV wants solid core? DC voltage to power the LMB. Not an issue with cable which is powered by the plant.
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Old 11-26-2013, 07:38 PM   #20
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How to check cable signal strength


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Originally Posted by Tonglebeak View Post
Also, you keep talking about DirecTV. The op has Comcast. Do you know why DirecTV wants solid core? DC voltage to power the LMB. Not an issue with cable which is powered by the plant.
It is called an example. In my area, Comcast also requires that solid core Copper is used, not CCS. I can tell that either you have not been around this stuff very long, or not very understanding why Solid Core is used, along with RG-6 by all providers, that care about their plant, and not having repeat calls, regarding line problems.

Copper Clad Steel is the worse invention ever made. It was done for cost savings by manufacturers, but in the end it causes more issues with Digital Signal transmission, for not only TV, but also Internet.

And yes those links do back up what I am stating, but it is obvious that you either never read them, or cannot understand the mathematics, along with Scientific information in them.
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Old 11-26-2013, 08:19 PM   #21
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How to check cable signal strength


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Originally Posted by gregzoll View Post
It is called an example. In my area, Comcast also requires that solid core Copper is used, not CCS. I can tell that either you have not been around this stuff very long, or not very understanding why Solid Core is used, along with RG-6 by all providers, that care about their plant, and not having repeat calls, regarding line problems.

Copper Clad Steel is the worse invention ever made. It was done for cost savings by manufacturers, but in the end it causes more issues with Digital Signal transmission, for not only TV, but also Internet.

And yes those links do back up what I am stating, but it is obvious that you either never read them, or cannot understand the mathematics, along with Scientific information in them.
So you're trolling. Tell me how any system that is all CCS can work if its impossible like you claim. All of our hard line, from 412 to 860, is CCS. All of our drop and in house cable is CCS. All of this and I have no issues reading a 40mer, 0ber@-5db behind the set with a tight constellation. Boy oh boy how does it work!!??!!??
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Old 11-26-2013, 09:13 PM   #22
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How to check cable signal strength


Excluding myself from any CCS debate

rg59 vs rg6, it's .77dB vs .57 dB loss per 100ft. Once you have already split a digital signal a couple of times, those dBs lost thru the cable itself start to matter.

I have used my cable modem to check strength on different cable outlets. my motorola SBG6580 will show for each of the 12 channels the SNR, and the power required for the 4 upstream channels. Rudimentary line meter.

with digital signals, db loss matters. a long run, especially with rg-59 can result in enough signal loss that not enough data is getting to the tv - causing pixilation or blanking screens. also how you split the signal matters.
from the service feed,
put on a 2 way splitter feeding the modem and then a 2nd line going into another splitter (2,3,4 no more splits than necessary). Some splitters split the signal equally, some split where one leg has less db loss - you'd use it to feed your longest run.

Just helping out friends, I've seen some horribly thought out splitting 'strategies' like the cable modem being behind 2-3 splitters. The typical 'my internet keeps going out' plea for help

Definitely would replace rg59. My home had plenty of it but replaced now. I ran big box quad with compression connectors. Big box 'quality' quad may be more marketing fluff than much better than dual shielded. ??
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Old 11-26-2013, 09:21 PM   #23
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How to check cable signal strength


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Excluding myself from any CCS debate

rg59 vs rg6, it's .77dB vs .57 dB loss per 100ft. Once you have already split a digital signal a couple of times, those dBs lost thru the cable itself start to matter.

I have used my cable modem to check strength on different cable outlets. my motorola SBG6580 will show for each of the 12 channels the SNR, and the power required for the 4 upstream channels. Rudimentary line meter.

with digital signals, db loss matters. a long run, especially with rg-59 can result in enough signal loss that not enough data is getting to the tv - causing pixilation or blanking screens. also how you split the signal matters.
from the service feed,
put on a 2 way splitter feeding the modem and then a 2nd line going into another splitter (2,3,4 no more splits than necessary). Some splitters split the signal equally, some split where one leg has less db loss - you'd use it to feed your longest run.

Just helping out friends, I've seen some horribly thought out splitting 'strategies' like the cable modem being behind 2-3 splitters. The typical 'my internet keeps going out' plea for help

Definitely would replace rg59. My home had plenty of it but replaced now. I ran big box quad with compression connectors. Big box 'quality' quad may be more marketing fluff than much better than dual shielded. ??
As you said, the setup with splitters is the biggest issue. I'd love to see a house where 100 ft home runs are being ran. most are less than less than that and the 59 is fine so long as it's aluminum foiled and 60% braided. If that extra db of loss is killing you then you're already on the border and need to fix the issue before that run.
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Old 11-26-2013, 09:27 PM   #24
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How to check cable signal strength


I also want to point out that in a lot of systems, putting a modem right off the first split is now outdated. With more devices relying on a return now, you need to balance the signal pretty evenly. Our DCXs will go into disconnect status if it can't get a return, so no more two ways straight to modems.
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Old 11-26-2013, 09:39 PM   #25
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How to check cable signal strength


Come on boys....behave....

First off....when quoting specs on cable...you have to say who the manuf is.....

Case in point...using Belden...@ 750 Mhz....RG6 has 5.5dB of loss/100'....RG59 9.7. But Extron brand is 6.5 for RG59.

Of course, the average person has no idea what dB is...much less the fact that 3dB is half the power or twice the power....

And I doubt anyone has any idea of what the incoming level is of their digital or analog signal is into their house.

In regards to Digital vs analog....sorry....but....a 200 Mhz digital signal is not really any different than an analog signal at 200 Mhz....except one is square (more or less) and the other is not. I'll save you the boredom of square wave infinite harmonics....

And lets not forget....coax is not the only way to transmit RF....Wave guides....rectangular tubes who's width and height is a function of wavelength. (or, the memories of tuning 10kw klystron's with wave guides)

What really matters....RG6 or RG59....the quality of the connection....

You can have the best coax in the world...but if you don't terminate it properly...then you get crap.

The center conductor is easy...the center wire (SC or CCS) sticks through the connector...hard to screw that up....most people screw up the shield....

And spare me the discussions of copper having lower resistance than steel....at RF frequencies, the characteristic impedance is not really effected by steel vs copper. The main reason copper is used is because it does not 'rust' like steel does. Your not passing any large amounts of current through it so any voltage drop is not an issue. Copper is used because it does not oxidize like steel or other metals do.

If you look at the conductivity chart....Silver is ahead of copper....further down is Gold and AL....Gold and AL are pretty much neck and neck....but we know the issue with AL....oxidation....gold is frequently used for contacts because of it's low oxidation factor as compared to copper.

So...at the end of the day....it's really a function of mechanical connections....how good are your connectors?

RG59 vs RG6? In most homes...you can't tell the difference...RG6 is better....but if the R59 has been in there a long time....and there are issues....at least replace the connectors.

edit...forgot to add....one issue related to Satellite....the antenna...the LNB might use DC for switching....(hence, the dual coax)....so....DC loss in R59 would be an issue as compared to RG6 which uses SC.
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Old 11-26-2013, 09:47 PM   #26
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How to check cable signal strength


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Originally Posted by ddawg16 View Post
Come on boys....behave....

First off....when quoting specs on cable...you have to say who the manuf is.....

Case in point...using Belden...@ 750 Mhz....RG6 has 5.5dB of loss/100'....RG59 9.7. But Extron brand is 6.5 for RG59.

Of course, the average person has no idea what dB is...much less the fact that 3dB is half the power or twice the power....

And I doubt anyone has any idea of what the incoming level is of their digital or analog signal is into their house.

In regards to Digital vs analog....sorry....but....a 200 Mhz digital signal is not really any different than an analog signal at 200 Mhz....except one is square (more or less) and the other is not. I'll save you the boredom of square wave infinite harmonics....

And lets not forget....coax is not the only way to transmit RF....Wave guides....rectangular tubes who's width and height is a function of wavelength. (or, the memories of tuning 10kw klystron's with wave guides)

What really matters....RG6 or RG59....the quality of the connection....

You can have the best coax in the world...but if you don't terminate it properly...then you get crap.

The center conductor is easy...the center wire (SC or CCS) sticks through the connector...hard to screw that up....most people screw up the shield....

And spare me the discussions of copper having lower resistance than steel....at RF frequencies, the characteristic impedance is not really effected by steel vs copper. The main reason copper is used is because it does not 'rust' like steel does. Your not passing any large amounts of current through it so any voltage drop is not an issue. Copper is used because it does not oxidize like steel or other metals do.

If you look at the conductivity chart....Silver is ahead of copper....further down is Gold and AL....Gold and AL are pretty much neck and neck....but we know the issue with AL....oxidation....gold is frequently used for contacts because of it's low oxidation factor as compared to copper.

So...at the end of the day....it's really a function of mechanical connections....how good are your connectors?

RG59 vs RG6? In most homes...you can't tell the difference...RG6 is better....but if the R59 has been in there a long time....and there are issues....at least replace the connectors.
You're mostly right. Copper does corrode though. That's why compression fittings are used instead of crimps. The center conductor will turn green or black or whatever and destroy the low end. Impedance mismatching is bad. Leads to reflections and other fun stuff. But yes, changing the fittings is the first step in troubleshooting cable (after checking signal)
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Old 11-26-2013, 09:56 PM   #27
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How to check cable signal strength


Also where are you seeing 9.7db per 100ft? That cable either has crap shielding or tbag number is way off.
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Old 11-26-2013, 10:06 PM   #28
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How to check cable signal strength


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Also where are you seeing 9.7db per 100ft? That cable either has crap shielding or tbag number is way off.
Belden

http://www.belden.com/techdatas/english/8241.pdf

And contrary to popular belief.....Belden is not always the best stuff out there.
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Old 11-26-2013, 10:10 PM   #29
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Belden

http://www.belden.com/techdatas/english/8241.pdf

And contrary to popular belief.....Belden is not always the best stuff out there.
I think you just linked me to what we call headend cable but I'm not entirely sure. I have never seen 23awg in the field. Ever. Link me to their 20awg.
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Old 11-26-2013, 10:20 PM   #30
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my signal loss numbers were way off.. must have been the loss at a lower frequency. rg59 specs 2.5dB loss at 50mhz (lowest vhf) and rg6 is 1.5dB... and at the highest uhf channel, is several dB in difference between the two.

and I was thinking recabling my home in terms of OTA frequencies and improving the line to my cable modem. and future proofing because in a few years our coax might be carrying lots more data...

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