|Topic Review (Newest First)|
|2019-09-30 07:45 PM|
Cannibalize a Cable Splitter...
Yes, I could make such a device. I'd just cannibalize a Cable Splitter like this:
But again, we'd just be checking the voltage level as we know it works now.
|2019-09-30 12:33 PM|
|ExDilbert||It should be possible to measure the voltages at the LNB with the current cables. You just need to fabricate a cable to connect a meter. Then calculate the voltage drop and current draw.|
|2019-09-30 12:43 AM|
Originally Posted by ExDilbert View Post
As far as "how the LNB draws its power. If it's shared between all 4 feeds than the total resistance will be 1/4 of each leg." Without a circuit to analyse we are just guessing. I'm an Electrician with a couple years of Electrical Technician/Technologist Training ages ago at BCIT on top of that, and without data, it's impossible for me to figure this out.
Hopefully someone we read this and offer up some suggestions or answers on how Shaw Direct calculates Vdrop on the cables.
|2019-09-29 09:42 PM|
|ExDilbert||Couldn't find any current specs for the Shaw LNB but it may be possible to construct a special cable and measure it with a meter. Contacting Shaw or the the LNB maker is another possibility.|
|2019-09-29 09:34 PM|
This might help Shaw Direct Blog
|2019-09-29 07:14 PM|
Now I'm stuck...
I keep coming back to this unit as a possible solution if the Cabling is marginal. It appears to be a unit used in multi-residence applications in High Rises or Apartments (Condos)
The 300 foot solution look intriguing...
I'd love to get a simple explanation as to how to do this type of install (maybe a handbook or on-line course). Just for educational purposes though. I'm not looking for a new career .
I found the following while checking out the SD PI-6S module. It's about DIRECTV® but I'm thinking the same standards / information would pertain to Shaw Direct. My comments in Blue
DIRECTV® recommends that the distance between receiver and dish be less than 150 feet of solid copper RG-6. Here is why.
The 18 volts originating at the SWM16 must arrive at the SL5 above 16 volts for the SL5 (the DIRECTV® LNB) to operate correctly. Up to (2) volts can be lost in the coax. (Jim's edit => this means the minimum switching voltage is 16 or 11 VDC depending on what polarity is being sought on our Shaw Direct Systems.)
Model SL5 LNBs employ current management to minimize the current carried per coax. (400 mA total) Rev3 SL5 LNBs splits the 400 mA current equally at 100 mA per coax.
Current x Resistance = Voltage loss
Solid copper RG-6 has a typical loop resistance of 4 ohms per 100 feet. At 200 feet the resistance is 8 ohms. 0.1 Amp x 8 ohms = 0.8 volts loss
18 V - 0.8 V = 17.2 volts to the SL5
Model SDPI6S-T starts with 19 Volts to provided extended dish to Main Point of Entry distances. The extra voltage provides an additional 150 feet RG-6 distance. Model LA146R off sets the signal loss of 150 feet of RG-6. The LA146R located at the polarity locker does not affect the current loss in the cable to the dish. What is the voltage loss in the 19V/22k coax? Assume 100 mA per coax.
At 300 feet the resistance is 12 ohms. 0.1 Amp x 12 ohms = 1.2 volts loss 19 V - 1.2 V = 17.8 volts to the SL5
This is quite different than the Spec in my post above ~20% less resistance => ANSI/SCTE 44, "at 68°F (20°C), the maximum DC loop resistance shall be 103 ohms per 1000 ft" Or about 10 ohms per 100 ft.
Assuming the former 4 ohms per 100 ft., for the Shaw Direct system at the cabin, the lines have a resistance of 3.55 X 4 = 14.2 Ω
14.2 Ω x 0.1 Amp =1.42 volts loss 18 V - 1.42 V = 16.58 volts to the Xku LNB if solid copper core RG6 were used. This should be fine as it's above the 16 volt minimum spec for switching.
Assuming the latter 10.3 ohms per 100 ft for the Shaw Direct system at the cabin, the lines have a resistance of 3.55 X 10.3 = 36.565 Ω
36.565 Ω x 0.1 Amp =3.6565 volts loss 18 V - 3.6565 V = 14.3435 volts to the Xku LNB if solid copper core RG6 were used. This should not work (or not work well) as it's significantly below the 16 volt minimum spec for switching.
If we calculate using copper-clad steel inner conductor, according to maximum spec, the maximum DC loop resistance shall be 201 ohms per 1000 ft. So the math becomes even crazier.
So obviously some thing is wrong with my data and/or methodology. We know Dual Shield RG6 copper-clad steel inner conductor works for the 355 foot run to the dish.
I've assumed the old Quad LNB had more output than the Xku, as when the Xku was installed, the run to the neighbor's needed a boost (in line amplifiers) to overcome the 277 feet to his place. The loss for those 277 feet should be less than that the 355 to the dish, so it shouldn't need the boost - but it does. My explanation was the multiswitches pushed more voltage to overcome insertion losses to the LNB Feeds (like the Model SDPI6S-T above which starts with 19 Volts) and that benefit overcame some of the line loss as "The extra voltage provides an additional 150 feet RG-6 distance." If that's the case then:
the lines have a resistance of 2.05 X 10.3 = 21.115 Ω
21.115 Ω x 0.1 Amp =2.1115 volts loss 18 V - 2.1115 V = 15.8885 volts to the Xku LNB if solid copper core RG6 were used. Even with the multiswitch boost this would allow for marginal switching.
RG6 copper-clad steel inner conductor, if calculated in this manner, gives even worse numbers as it's more lossy than solid copper.
Now I'm stuck...
|2019-09-29 03:36 PM|
Hi ExDilbert & All,
Just a quick note for reference. I found the applicable ANSI Specifications for interior applications, and surprise it's quite recent (2018) which is a bonus. I suspect the exterior version of this spec, which I couldn't find, is not much different except for the outer jacket performance under environmental stress testing.
ANSI/SCTE 244 2018
Specification for Braided 75 Ω, Micro-Series Quad Shield Coaxial Cable for Connectivity and Dense CCAP/Edge QAM Applications
10.2.4. =>When tested in accordance with ANSI/SCTE 44, at 68°F (20°C), the maximum DC loop resistance shall be 103 ohms per 1000 ft (338 Ohms per km) for cable with solid copper
For cables utilizing silver-plated, copper-clad steel inner conductor, the maximum DC loop resistance shall be 201 ohms per 1000 ft (659 Ohms per km).
For this application that means the voltage drop from the multiswitch to the Dish is almost double using copper-clad steel inner conductor, versus a cable with a solid copper inner conductor. Using 355 feet from the Cabin to the Dish (and 277 feet to the Neighbors from the dish) I suspect this could have some impact on switching at the LNB (or multiswitch in case of the neighbor). But without knowing the typical current, and reliable voltage switching limits at the LNB I really can't go much farther.
Using basic math 355 feet X 0.201 Ω/Foot =71.355 Ω DC resistance in a single cable. (55.677 Ω DC resistance for the cable runs to the neighbor's)
The "old" Phillips SDW5058 multiswitch power supply was 24 VDC at 750 mA Max. I've got no idea how much of the supplied current is sent down the line, but I know it's not much. If known then the Vdrop = IxR would be a simple calculation. Maybe a Shaw Direct (or other) Tech could chime in with the right procedure to figure this out.
I do know when we had continuous no broken cables from the LNB to the Cabin, even the cheapest RG6 Cable used worked fine for 7 years. So perhaps I'm just wasting my time going down this road.
|2019-09-29 03:12 PM|
Solid copper may be better for DC resistance. That could help with powering the LNB but they seem to be fairly tolerant of lower voltages. At RF frequencies there shouldn't be too much difference.
Rocks and stones are an issue with buried cables, especially with direct burial or soft plastic pipe. Putting sand around the the cable or plastic pipe is recommended in rocky soil.
|2019-09-29 03:26 AM|
Of course the plan evolved...
As per this earlier post (https://www.digitalhome.ca/forum/11-...ml#post1148421) the plan was ...we'll run the cables inside a conduit beside the road about 18 inches deep back to the Cabin.
Of course the plan evolved...as per this post (https://www.digitalhome.ca/forum/11-...t1173676)...We were going for a 4 inch wide a foot deep but it wandered up to about 6 inches and down to 1.5 feet. (It took about 6 Hours with all the rocks and hand digging!)
We've had no cable issues for the first 7 years, but the construction 2 doors down, and the changes they made to the road grade during the last couple years (About a foot lower so the cable was only about 6 inches down across their driveway), along with the movement of heavy equipment over and over the conduit & cables, is what lead to the first, and now the second failure.
I'm actually surprised when I look back at how long it's lasted, & how well it performed all these years before the break. (It did take a little effort to boost the signal to the neighbor once the XKu LNB was installed.) Half of the original Cable was provided by my brother in law (the cheapest outdoor rated cable), and later the rest by the neighbor which had Gel between layers to prevent moisture ingress. Both were no where near the Quad Shield RG6 Steel core minimum Satellite specification I had asked for (and they said they'd provide).
At one time I was thinking Quad Shield RG6 Solid Copper Coaxial Cable but it was about triple the price per foot as I remember. At the end of the day, both Quad and Dual Shield have the same DC Resistance per Conductor @ 20°C @ 28 Ω/1000 ft Nominal. I assume Quad Shield RG6 Solid Copper Coaxial Cable will be less but I can't seem to find that info tonight. In hindsight, if it is substantially less lossy we should have bit the bullet and just paid for it.
I expect we'll be pulling all new cables next spring so I'll be sure to get it sorted long before then.
|2019-09-28 09:59 PM|
I had forgotten that the cable was damages by heavy equipment. It's not necessary for low voltage cables like satellite but I believe the rules for electrical cables specify a minimum 18" depth with 3' under driveways. Roads may be deeper or at least require extra protection such as metal conduit or concrete encasement to protect from damage.
Bell and Rogers barely bury their cables at all but they are constantly being damaged and pulled up by people putting in new driveways or digging in their gardens. I've exposed the Bell cable several times here. One time I found a section it just laying on top of the ground in the front yard. The Rogers cable has been cut twice by other people and the new one is barely 3" below the surface at the edge of the driveway.
|2019-09-28 06:35 AM|
|LONSat||Glad you got all your channels back. I expect the problem may come back as the splice is still there and water likes to go where it shouldn't. ExDilbert is probably right and that direct burial cable is probably best in the long run.|
|2019-09-28 02:19 AM|
Here's the latest. The Tech came on Wednesday, and again on Thursday before he left for Kelowna for Friday. He replaced the LNB and one (on the Line/Cable I deemed dead earlier), possibly two of the Aqua Tight F connectors at that end. He changed out the Multiswitch (supposedly because it was one volt off => I'm assuming because it says 17 and not 18 volts. I assumed he changed this to make it Shaw Direct spec compliant, and not because of any malfunction in the switch.) He agreed the LNB was faulty but the some (?) of the cables weren't functioning (I assumed shorted after talking to the neighbor).
I earlier advised the neighbor that I suspected the connections on the bad line could have come ripped out (Another neighbor (Nick) who is two lots west of our cabin is rebuilding his place into a full time residence, and had damaged / cut through the Cables last October 6th (see previous post), and the heavy equipment going back and forth over the year eventually caused the tightest line to pop one of the F connectors off the line at the splice. We had dug this section of the conduit down last year to try to avoid this happening again.
The damaged Cable, along with the other 3 spliced cables were immersed in water due to the heavy rains the last few weeks - and the low point we created. Even though I had used vulcanizing tape, water penetrated the splice and (according to the neighbor) rusted the connections to the copper coated steel center conductor. The Tech gave the Neighbor 3 F connectors before he left and the neighbor used 3 of his screw-on type just to make the connection => as Nick was pushing him to finish up as he had truckloads of gravel coming for his driveway tomorrow.
Right now all of the channels are coming in so the neighbor, although tired, is happy with the result. I hope they last until spring as no one wants to be digging up anything in Winter. At least if winter comes early, then everything will freeze and no water will flow to contaminate the splices. I'm thinking we'll be pulling all new Cables next year.
|2019-09-22 11:20 PM|
|ExDilbert||It may be better to replace all the cables with something rated for underground burial. The cost difference is not usually that great since it's typically just an upgrade to the external insulation. Buying whatever an installer has on his truck may not be the best long term plan.|
|2019-09-22 12:53 PM|
|JasperJoe||Balked at $20??? I hope you're in his will because he's not spending his money in this lifetime!|
|2019-09-21 04:21 PM|
More Twists and Turns
Here's the latest update. The neighbor decided that everything was fine, so he stalled on contacting Shaw Direct...
This week I was up at the Kemess Mine in Northern BC on business (with no cell coverage for 3 days - but they have a weak WiFi setup). My wife texted me that the neighbor called her and is upset that he's lost a lot of channels (including his favorite AMC - CH 130 / 630) and wants me to call him right away. She said he's been in contact with Shaw Direct, and they (again) say they want to send a Tech out before providing a new LNB. Of course I can't call him and he doesn't text, so I got my brother who just happened to be up there (and will winterize the Cabin today) to advise him to let Shaw send at Tech.
The neighbor decided to wait (and become more frustrated) until he talked to me, so while en route back to Vancouver, I had a layover at the Prince George airport (with good cell coverage) and I called him. I advised I'd have no problem letting a Shaw Direct Tech tinker with the system as long as he stays out of the Cabin when we are not there. With the multiswitch on the outside, there is really no need to go inside anyway. The neighbor said the Tech wasn't a Shaw employee but rather a contractor, and he wanted $20 for mileage. The neighbor was balking at the $20 so I said I'd split it with him if he fixed it and installed a new LNB. This save me the trouble of going all the way to Kamloops to try to get it sorted. So $10 is a bargain. Even $30 is... maybe $100...
I also asked him to ask the Tech if he'd sell us a spool of RG6 Quad Shield, or tell us if there is a local distributor in Kamloops as we'll need to pull a new line in the spring. (See previous posts) I called back the next day when I was at home, and the neighbor's wife was the only one home, but she said the Tech will be out next Wednesday or Thursday.
I'll advise what happens then.
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