What is CT100 cable?
Discussion
In my continuing multimedia quest I have come up against this problem. Speaking to people on the phone, they tell me I need to run CT100 cable for tv/video. But I think they are using this in a legacy/generic kind of way because (and I quote a website):
"*CT100 supplies have disappeared since the manufacturer "Raydex" was taken over"
So what is CT100 and what is the up to date name for it? I believe it's that fairly stiff cable which runs from the satelite dish to the decoder but what is it called today?
cheers
Driller
"*CT100 supplies have disappeared since the manufacturer "Raydex" was taken over"
So what is CT100 and what is the up to date name for it? I believe it's that fairly stiff cable which runs from the satelite dish to the decoder but what is it called today?
cheers
Driller
www.satcure.co.uk/accs/page8.htm
As it says!
Edited to add, you could always use semi-rigid!
Further edited to add;
By the looks of it you just want 75 ohm co-ax. The only other important parameter for co-ax is loss. For most people, the loos is probably not going to be important, and it's always going to be difficult to know what loss is tolerable, because you don't necassarily know the RX signal strength.
It is however important that the integrity of the cable is not compromised, because the impedance of the cable is determined by it's cross sectional physical dimensions. If the cable is crushed, for example by bendng, then the charateristic impedance will change, the SWR will go to pot, and the loss will rise considerably.
Whatever cable you use, make sure that the bend radii are as large as possible.
>> Edited by dilbert on Wednesday 14th December 11:14
As it says!
Edited to add, you could always use semi-rigid!
Further edited to add;
By the looks of it you just want 75 ohm co-ax. The only other important parameter for co-ax is loss. For most people, the loos is probably not going to be important, and it's always going to be difficult to know what loss is tolerable, because you don't necassarily know the RX signal strength.
It is however important that the integrity of the cable is not compromised, because the impedance of the cable is determined by it's cross sectional physical dimensions. If the cable is crushed, for example by bendng, then the charateristic impedance will change, the SWR will go to pot, and the loss will rise considerably.
Whatever cable you use, make sure that the bend radii are as large as possible.
>> Edited by dilbert on Wednesday 14th December 11:14
Thanks for the replies guys. The problem is is that I live in feckin' France and their coax references are all different! They use VATC21, VATC19 and VATC17 for example. However they are all 75Ohm cables so can I identify which one is CT100 by the loss spectrum (as you mention Dilbert) and would that alone guarantee the right cable?
>> Edited by driller on Wednesday 14th December 11:28
>> Edited by driller on Wednesday 14th December 11:28
driller said:
Actually Dilbert I just re-read your post and I see that you already answered my dumb question. 
Cheers
Driller
No your post was fine as far as I can see. I was just trying to think of a simple answer.
For a given Rx frequency, you wouldn't want a cable that has a 3dB bandwidth is outside the Rx frequency.
Some of them are optimised for particular applications, but so much of this argument is dependent on the receive power, the gain in the LNB, and te sensitivity of your receiver. Unless you already have the kit to make the measurements, it's gonna be expensive to work that out. You could get someone in to do it, or you could chance it on a similar cable type. It's probably going to be OK, as long as you have the characteristic impedance right, but it's not like cable costs the earth.
If you know the Rx frequency and bandwidth, and you can get graphs for the loss spectrum that match for your "known", and "unknown" cables, then you've made an informed choice. I don't have these graphs to hand, but the manufacturers usually provide them.
I guess the trouble is finding out the parameters for the "known" cable!
HTH
>> Edited by dilbert on Wednesday 14th December 11:57
CT100 is the generic term for high quality digital certified coaxial cable.
CT100 is actually a single makers model code but its whats been adopted as what to call 75ohm copper shield and braid, hollow conductor coax.
RG6 (and for that matter RG59), whilst being similar spec is NOT the same thing. RG cable is for CATV.
Sky for instance will ONLY entertain certified CT62 (Shotgun 100 2 cables paired on one reel), CT100, CT125 and CT162 (Longer runs=thicker cable) for Digital Sat TV.
Unless you are going a long way I would stick to CT100 coaxial as its a fair price point, espcially on 250m+ drums.
There are a number of manufacturers of CT100 grade cable.
>> Edited by Plotloss on Wednesday 14th December 18:31
CT100 is actually a single makers model code but its whats been adopted as what to call 75ohm copper shield and braid, hollow conductor coax.
RG6 (and for that matter RG59), whilst being similar spec is NOT the same thing. RG cable is for CATV.
Sky for instance will ONLY entertain certified CT62 (Shotgun 100 2 cables paired on one reel), CT100, CT125 and CT162 (Longer runs=thicker cable) for Digital Sat TV.
Unless you are going a long way I would stick to CT100 coaxial as its a fair price point, espcially on 250m+ drums.
There are a number of manufacturers of CT100 grade cable.
>> Edited by Plotloss on Wednesday 14th December 18:31
driller said:
Matt I just emailed Russound and they recomended RG59. Now I'm completely confused!
Attached are two specs, one for RG6 and one for RG59;
RG59
RG6
I'm guessing that the satellite transmits at about 10GHz, but I'm not sure if the data is partially decoded at the dish. Either way niether of the specs here cover frequencies as high as 10G. Losses would be quite high maybe as much as 10dB in a 10M run.
The RG6 looks better than the RG59.
Edited to add; this doesn't allow for the variety of suffix types that might be available for either cable type.
>> Edited by dilbert on Wednesday 14th December 22:13
Funnily enough, I just had a squint on the RS website. They stock your CT100, and it just looks like the crappy stuff they sell in electrical factors. Certainly the stated performance doesn't look that good comparitively.
That certainly fits with much lower frequencies/bandwidths.
Edited to add;
The other benefit of the CT100 is that it has a plastic dielectric, which can only be good for going up the outside of brickwork.
>> Edited by dilbert on Wednesday 14th December 23:40
>> Edited by dilbert on Wednesday 14th December 23:45
That certainly fits with much lower frequencies/bandwidths.
Edited to add;
The other benefit of the CT100 is that it has a plastic dielectric, which can only be good for going up the outside of brickwork.
>> Edited by dilbert on Wednesday 14th December 23:40
>> Edited by dilbert on Wednesday 14th December 23:45
driller said:
Matt I just emailed Russound and they recomended RG59. Now I'm completely confused!
Russound are American, almost all US coaxial is either RG6 or RG59 (same specs near enough, 59 is more flexible though) as CATV is highly prevalent out there.
I keep forgetting you're in France, so Sky may not be an issue?
If you are planning on having digital satellite I would suggest CT100 grade certified coax. If not then RG6/59 will be fine.
It looks identical to cheap coax, its the quality of the build thats a lot higher with 100.
roop said:
I always use the ultra low-loss coax for installations of any kind - works much better over longer runs.
dilbert said:
Which as far as anyone can tell is probably CT100!
It's RG-59/U
If you are playing with higher frequencies and want top drawer gear, then Times Microwave make the best stuff. Have a look at something like LMR-200, 240, 300, 400 or 600. It's the cats ass but pricey. I use Times Microwave for all my important stuff.
Plotloss said:
Matt I just emailed Russound and they recomended RG59. Now I'm completely confused!
Russound are American, almost all US coaxial is either RG6 or RG59 (same specs near enough, 59 is more flexible though) as CATV is highly prevalent out there.
I keep forgetting you're in France, so Sky may not be an issue?
If you are planning on having digital satellite I would suggest CT100 grade certified coax. If not then RG6/59 will be fine.
It looks identical to cheap coax, its the quality of the build thats a lot higher with 100.
OK happy and smiling again, thanks!
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