Cable Resistance

  • 1
  • Question
  • Updated 2 years ago
  • Acknowledged
3 weeks ago, I had a service call and, my cable to my dish was replaces. Now that's 35 FT of cable. At the time, I had the SB2 modem. Resistance was 1.5 ohms. Two weeks ago, I got the SB2+ (Boost) Modem. For a few days resistance held at 1.5, three days ago it went up to 2.0 ohms and today, it's at 3.0 ohms.

# weeks ago, my TRIA and dish were also replaced, so it's basically a new system now. What would cause the cable resistance to keep climbing like that?
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes

Posted 2 years ago

  • 1
Photo of Gregory Davis

Gregory Davis

  • 98 Posts
  • 55 Reply Likes
My first thought would be the weather.  For exmple if the outside cabling (coax) maybe collecting moisture from either rain and/or condensation issues.  Not sure how many connectors there are between the TRIA and your modem?  Are these connectors tight - don't overtighten them but if you can turn them with your hand then that's a little too loose.
Photo of Matt B

Matt B, Viasat Employee

  • 904 Posts
  • 472 Reply Likes
Gregory took the words right out of my keyboard!  

That's my first thought as well.  Look at the connections, unscrew them and see if there's moisture inside.  
Photo of Markgc

Markgc, Champion

  • 340 Posts
  • 92 Reply Likes
I always seal my coax connections with coax seal and have never had any water issues.  https://www.summitsource.com/Coax-Seal-Coax-Sealant-Tape-for-Fittings-Hand-Moldable-Plastic-60-Long-...
Photo of Brian

Brian, Champion

  • 296 Posts
  • 216 Reply Likes
Do you think heat shrink tubing would work?
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes
I think that would work too, just grease makes it easier to disconnect them if need be later than other products do.
Photo of Markgc

Markgc, Champion

  • 340 Posts
  • 92 Reply Likes
Do you think heat shrink tubing would work?
It is not normally used. You could try the adhesive flooded heat shrink but I use products designed for coax sealing.      I also use  Scotch 130C

http://multimedia.3m.com/mws/media/37648O/scotch-linerless-rubber-splicing-tape-130c.pdf

On the big coax. I put on a layer of 130C then a layer of Scotch Super 33 insulating tape, then a layer of coax seal and then a final layer of Scotch Super 33. I make sure that I lay the tape from the bottom upwards, like the shingles on a roof, so that the joints are facing downwards. Nothing is going to get into the coax then.  Always cut the tape with a pair of scissors don't pull it to break it.

I use adhesive heat shrink on the coax end of  PL259 connectors.
(Edited)
Photo of Gwalk900

Gwalk900, Champion

  • 451 Posts
  • 471 Reply Likes

Bev, did the installer apply dielectric grease to all outdoor connectors and then properly weather seal the connection?

Moisture can condense in the "void" within the connector that will lead to issues.  

Photo of Markgc

Markgc, Champion

  • 340 Posts
  • 92 Reply Likes
Never seen an installer do this. I normally seal the connectors after they have left. I don't think it is part of the installation instructions.
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes
Thank you all :) it's fixed now. The outdoor connections were greased, the one that wasn't was the back of the modem inside, of course. It had a bit of moisture in it. Leave it to hot, humid southern days, cool damp nights, my air conditioner and, Harvey to do that. I dried it with q-tips and SD alcohol, reconnected it. I didn't grease that one but, I know what to do when it does that again.

That is going to be a recurring thing at certain times of the year here. Also good to know if it happens to others in similar climates.

NOTE TO OTHERS: Be very careful doing what I did, if unsure of yourself, call for a service call and, let a technician do it. I build my own computers, among other electronics hobbies, so I'm fine doing little things like that and, know to be careful not to bend or break anything and, make sure it's 100% dry before reconnecting it.
Photo of xode0000

xode0000, Champion

  • 496 Posts
  • 167 Reply Likes
You might want to grease that connector.  If water were to again get it there, it could cause a short, which would definitely create a problem for the modem.
Photo of Andy Schack

Andy Schack

  • 854 Posts
  • 756 Reply Likes
Bev, are you saying you had moisture in the connector INSIDE the house at the modem? The reason I ask is that in 17 yrs of internet satellite (started with Starband) I haven't run into this solution before....I like to learn things. Usually when I see degrading ohm readings it ends up being a coax issue, sometimes you can even see anything physically wrong with the coax but when you replace it, everything starts working like it should. I've even seen coax read open, in other words you put a toner on one end and get nothing on the other....it's just like you cut the coax, YET the coax looked perfectly fine...not even a kink. Every day's an adventure.

Andy
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes
Yes, humidity in my home is always 80% and above. I run window unit air conditioners to keep the house cool. With Harvey here, indoor humidity is hovering right at 95% and, it's getting down into the mid 60's at night indoors and, 85 during the day.

The room the modem is in is also open to the kitchen and, canning and, general cooking adds steam to the air on top of the ambient humidity. Not surprising to me, with the temperature changes and, high humidity, condensation happens.

Windows have been fogged up every evening from about 9PM until about 8 AM every day since Harvey made landfall. Without a storm making it this damp and, creating such a large temperature change every night, it wouldn't happen. If I had central air, or ran dehumidifiers it wouldn't happen. May not happen if I didn't can or boil as much food in the kitchen, or if the modem were more isolated form the kitchen either.
Photo of Markgc

Markgc, Champion

  • 340 Posts
  • 92 Reply Likes
With humidity levels that high I would be concerned about mould growth in the house and within the wall cavities.  You might want to look at getting a dehumidifier.  They have worked well for me in the past.
(Edited)
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes
Money, money, money. Yes mold is a problem in my area, but, I use cleaning products and do check crawl spaces and the attic twice a year. Personally, I'd sped the 400 or so for a whole home dehumidifier but, DH says air conditioner already cost too much, and uses too much electricity. (He lived in Florida WITHOUT air conditioning most of his life so, doesn't think we really need it here.)

Maybe I'll get a new job and move to Colorado. XD
Photo of Andy Schack

Andy Schack

  • 854 Posts
  • 756 Reply Likes
Bev, you might want to consider installing what is called a mini-split or ductless a/c unit. They are extremely energy efficient and will do wonders with overall comfort and moisture extraction. We added on about 800 sq ft a few yeas ago and I bought one and am VERY happy with the investment.

Andy
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes
I will look into that, it may be more cost effective than window units, though I suspect the layout of my home would require two units without duct work being involved - one section is isolated form the rest of the house 99% of the time.
Photo of Captain318

Captain318

  • 38 Posts
  • 10 Reply Likes
Mine sometimes climbs up and all I have to do is restart the modem and it's ok again
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes
Might be a reason for it, if it's the SB2+ (Boost) modem, I'd be curious to know if others are seeing the same thing with it.
Photo of Captain318

Captain318

  • 38 Posts
  • 10 Reply Likes
Its the old modem. Never have issues with service but still, Attenuation or Resistance climbs up ever so often. My install is about 5 yrs old and Ive only ever had one service call for a re peak.  I'm online 99.8% of the time with SNR between 7 - 10 most of the time. When it reports funky things I just reboot and go on with life just like I do with my router. I'm a PC technician and maintain my own equipment and build my own systems so I know when things aren't working properly and are in need of attention. Both the Exede system and my old Wildblue system have always been rock solid. Never could I have said that about Hughes back when I had them. That was a bad joke
Photo of Andy Schack

Andy Schack

  • 854 Posts
  • 756 Reply Likes
I love it when I install a system for guys like Dallas! They are usually very knowledgeable and don't mind sharing that knowledge. It was from someone like him where I learned about the importance of having a device or computer with a GOOD processor. He said one of his biggest problems is that folks will go to some place like Walmart and buy one of the cheaper laptops with the AMD chip and then bring it to him because it pulls web pages so slow.
Folks, when you go to most web pages these days there are often 30-50 things loading in the background that YOU never see going on but they will bog a wimpy processor down to a crawl....even with a good Intel processor it can still take 20-40 seconds for a page to finally "settle down". His advice to me was to buy a laptop with an Intel I5 or I7 chip. I promptly bought an HP Elite book with an I5 and it runs like a scalded dog compared to my old laptop that had the AMD chip.
Same thing goes for those cheap tablets you see in the big box stores. There's a REASON that the Samsung or Apple tablets cost so much more than those RCA ones. And don't EVEN get me started on the built-in streaming software that comes with most TVs and Bluray players...they are a connectivity nightmare.

Andy
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes
So true, my I7 (4.2gHz) runs circles around my husband's Pentium (1.6 gHz) and, he often wants me to fix his computer because webpages are loading slow. He won't spend the money for a better rig, so not much I can do beyond clean up and turn off stuff - which he will enable again inside a month. He does it to his phone too, never closes an app when he is done using it, then wonders why it messes up with 50+ apps open in the background.

Some days I just want to beat him over the head with his devices  - one thump for every open app that should not be left open. LOL
Photo of Jim

Jim, Champion

  • 542 Posts
  • 279 Reply Likes
Bev, It probably has nothing with your issue but in my Exede Installer training we were told that there should always be a MINUMUM of 40 ft of coax from TRIA to Modem because some attenuation is desirable. I need to research to see if this is actually in the standards or if it was just the opinion of the instructor.
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes
And my installer told me that the 75 ft the previous installer gave me was too much, it was causing higher attenuation and resistance, should be as short as will reach comfortably. He said that attenuation reduces signal strength and, in an area where 7.0 is the best SNR you can get, the lower the better. There will always be some because using lower attenuation materials, like gold, would be cost prohibitive for home internet.
Photo of Andy Schack

Andy Schack

  • 854 Posts
  • 756 Reply Likes
I did an install a while back Bev where there had been an Exede system before, all I had to do was install and point the dish. Good for me, right? Wrong. Had to do a follow-up svc call a week later. Resistance was very high. Crawled up in the attic and found where the previous installer, for SOME reason, had rolled up about 50 ft of coax in a tight little wad. Cut that mess out and all has been fine since.

Andy
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes
That was mine, among other speed and SNR sapping minor things, except the excess coax was under my house (4 ft tall crawl space so not bad to get to the problem.) Fixing all the minor things made a big difference in speed and a small difference in SNR.

I respect installers that take the time to test every possible cause of a problem, or diagnose a system thoroughly when doing a service change. The one that fixed mine replace the coax, replaced the TRIA, replaced the modem, even replaced the dish itself in the process of trying to get me the best possible service. He was determined to get that SNR at 9 or better - ended up at 7.2 with nothing more that could be done. Just the area I live in. Even DirecTv can't get above 80 on any transponder.

You sound like that kind of installer - the kind Viasat needs to find more of. :)
Photo of xode0000

xode0000, Champion

  • 496 Posts
  • 167 Reply Likes
Bev, It probably has nothing with your issue but in my Exede Installer training we were told that there should always be a MINUMUM of 40 ft of coax from TRIA to Modem because some attenuation is desirable.
I can confirm, using my installation as an example, that there definitely needs to be at least 40 ft of cable and at least one ohm of cable resistance between the modem and the tria.  If you don't have that attenuation, then voltages, large enough to potentially wipe out both the modem and the tria, will build up in the circuit between the modem and the tria due to electronic resonance.

When my service was first installed, the cable between the modem and the tria was only 10 ft.  It wasn't long before the service started intermittently cutting out for a few minutes at a time every so often.  Then, about a month after the service was first installed, the service cut out for about 22 hours and, when I looked at the modem status page, it said that there was a problem with the IFL.  I then had a service call done where the 10 ft cable was replaced with a 40 ft cable between the modem and the tria, and there hasn't been a problem with the IFL since.
Photo of Bev

Bev, Champion

  • 3287 Posts
  • 1462 Reply Likes
Well mine is fine 2 Ohms and attenuation at 6.0, beats the 3.5 ohms and 20 or so attenuation I had before.
Photo of Markgc

Markgc, Champion

  • 340 Posts
  • 92 Reply Likes
I disagree about the coax length. I had about 15 feet on my Wildblue setup and I have about 15 feet now. Both installations have worked perfectly for many years.  My attenuation is 4.0 and the resistance is 1 ohm now.
Photo of Captain318

Captain318

  • 38 Posts
  • 10 Reply Likes
In regards to AMD chips that were discussed earlier, AMD has been catering to the low end market for some time now and with a very poorly designed architecture and until recently some of their best chips were comparable to Intel's worst. That however has changed this year with AMD's new Zen architecture. AMD has shifted focus back to the higher end and mainstream CPU market. Zen or AKA Ryzen is within 9% IPC of Intel's most recent architecture Kabe lake. Ryzen chips are a good value considering their Core Counts and Price/Performance Ratio. Those that have been in my line of work remember the old days when AMD dominated Intel in the CPU market and remember when Intel made some of the hottest, slowest and most expensive chips on the market with the poorest value. It's nice to see AMD back in the running and putting an end to Intel's long running monopoly. Ive been running elusively Intel CPU's for more than a decade now and even I am upgrading my Intel i7 6700k to a AMD Ryzen 1800X
Photo of Captain318

Captain318

  • 38 Posts
  • 10 Reply Likes
In regards to AMD chips that were discussed earlier, AMD has been catering to the low end market for some time now and with a very poorly designed architecture and until recently some of their best chips were comparable to Intel's worst. That however has changed this year with AMD's new Zen architecture. AMD has shifted focus back to the higher end and mainstream CPU market. Zen or AKA Ryzen is within 9% IPC of Intel's most recent architecture Kabe lake. Ryzen chips are a good value considering their Core Counts and Price/Performance Ratio. Those that have been in my line of work remember the old days when AMD dominated Intel in the CPU market and remember when Intel made some of the hottest, slowest and most expensive chips on the market with the poorest value. It's nice to see AMD back in the running and putting an end to Intel's long running monopoly. Ive been running elusively Intel CPU's for more than a decade now and even I am upgrading my Intel i7 6700k to a AMD Ryzen 1800X
Photo of Captain318

Captain318

  • 38 Posts
  • 10 Reply Likes
Not sure why that posted twice
Photo of Michael McDowell

Michael McDowell

  • 591 Posts
  • 222 Reply Likes
How is this related to cable resistance?
Photo of Captain318

Captain318

  • 38 Posts
  • 10 Reply Likes
Scroll up. It was in response to a comment by Andy Schack. Just sharing some information
Photo of Captain318

Captain318

  • 38 Posts
  • 10 Reply Likes
Scroll up. It was in response to a comment by Andy Schack. Just sharing some information
Photo of Barry Paepcke

Barry Paepcke

  • 94 Posts
  • 12 Reply Likes
reading this post about resistance I just ck mine and it is 4.0 is that something to be concerned about?

Photo of Andy Schack

Andy Schack

  • 854 Posts
  • 756 Reply Likes
Barry. 4 is definitely on the high side BUT...BUT, if everything is working fine then "don't fix it if it ain't broke". If it ends up being a problem what you'll start experiencing your modem all of a sudden rebooting...working for a while and then rebooting again. If that does begin to happen, call and have a service call set up.

Your installer probably used your existing coax......I've done the same...only problem is that now it is causing a problem. He might have to run a dedicated line.

Andy
Photo of Jim

Jim, Champion

  • 542 Posts
  • 279 Reply Likes
Barry - 
Take a look at the printing on your cable jacket. You should see either a "CC" or "SC" printed on it. "SC" is for "solid copper." Solid copper is required and your installer should not have used existing cable unless it was solid copper.