Best Coax Cable For TV Aerial/ Sat Systems

March 13, 2019
by
Tom
coax-cable-thumb

Best Coax Cable For Freeview, Freesat & Sky

 

You’re probably already aware that there are loads of different types of coaxial cables on the market and if you’re looking for the best cable to be wiring your TV system with, then read this article for all you need to know. I will go through all the common coaxial cable types and terms, showing which coax cables to avoid and what to look out for. Once reading this you will be able to decide what coaxial cable will be best for your aerial or satellite system. It could also be that you're have poor TV reception and replacing the connecting coaxial cable will help improve your TV signal.

 

Please note that this has been written from a TV aerial/satellite perspective, so we are focusing on the best coax cables for Sky, Freeview & Freesat. There are lot of other types that are used in CCTV and data cabling functions which are not mentioned in this blog.

Components of A Coaxial Cable

 

Before we start it will be helpful to talk about all the different parts that make up a coaxial cable. From here we will be able to demonstrate what the different is between coax cables.

 

The Centre Conductor 

Centre-Conductor

The centre conductor is the solid metal conductor that runs through the centre of the cable. This is the most important part where most of the signal will be transferred. Copper is the optimum centre conductor of choice, but many cables use steel or copper clad steel (CCS) instead, this is to keep the cable cost down. You will occasionally find in old TV systems and cheaper factory fly leads a stranded centre conductor. Avoid this type of cable at all costs, even short sections of it as the insertion and signal losses will be astronomical, meaning you will quickly run out of signal.

 

Cable Braid – Ground Shield 

The next prominent part of a TV aerial/ sat cable is the ground shield, most commonly known as the cable braid or cable mesh. This is the thin wiry part just below the cable sheath. The cable braid has a few purposes. Its primary purpose is to help create the electrical circuit to allow the signal to flow. Therefore, it must be connected to the coaxial plug itself or wall plate, failing to do so will result in a dramatically weaker signal or no signal at all where there is line power present, like the DC voltage required to power satellite LNB’s and masthead amplifiers. The cable braid also acts as a shield to protect against RF interference penetrating to the centre conductor and to stop RF leakage from the centre conductor. This means that cables with a heavy thick coaxial ground shield will out perform those that are not so thick, a further improvement on this is a separate screen installed inside the aerial/ sat cable which I will come to shortly. Again, like the centre conductor the optimum cable braid of choice is copper, but other cables again use steel and copper clad steel.

 

Dielectric Material 

When installing a coaxial cable, it is imperative at that the centre conductor and the cable braid and centre never touch, even one single strand of the cable braid touching the centre conductor will create a cable short and could result in loss of TV signal altogether. This definitely will happen where line power is present which could be powering your satellite dish, amplifiers and magic eyes. As the dielectric inside a coax cable is to primarily stop the conductors touching this must made from a non-conductive substance with insulating properties. This is most commonly a foam filled substance,but some coax cable types use a PVC/ air where the PVC keeps an air separation.The dielectric also helps define the impedance of the coaxial cable, so it is also carefully keeping the correct distance between conductors. For this reason,it is important not to squash the cable at terminations or kink the cable when installing it.

 

Cable Screen (Double Screened Coaxial Cables Only) 

A cable screen is a metallic substance that is usually installed directly beneath the cable braid. This is a conductive material with no gaps in it like the cable braid. Not all coaxial cables have a cable screen,but most new ones do. TV/ Sat cables without a cable screen inside are called“single screened cables” and cables with a cable screen are called “double screened cables”. A cable screen will dramatically improve the performance of the cable, it will improve signal losses and protect against RF/ EMF interference and RF leakage. It is absolutely imperative when installing coax cables for satellite systems like Sky & Freesat, that you use a double screened cable as the higher frequencies used for satellite will quickly be lost down a short section of cable. It is also very important when installing coax cables for aerial systems like Freeview and BT Vision, where short sections of single screened are encountered it should be replaced where possible.

 

Cable Sheath / Cable Jacket 

cable-sheath

Something has got to hold all this together and this is the cable sheath. This is usually made of PVC, which although isn’t 100% waterproof will protect against weathering and rainwater. This is because most coaxial cables for aerial & satellite TV are installed outside and water, being itself conductive must not be allowed to enter the inside of the cable as water in the coax could create a cable short and create no TV signal. Where installing coax cables outside you must make sure that the cable is UV stable, as if it isn’t it will quickly fall apart. Although not always observed in domestic/ residential situations cables installed internally should be Low Smoke Zero Halogen (LSZH).I will discuss this later in the article.

 

Coaxial Cable Impedance – 50/75/300 Ohm 

You may come across the term impedance when purchasing your coaxial cable.  I’m not going to go into this at great length here as this is another blog itself, but TV aerial and satellite systems use 75 Ohm coaxial cable, the standard for this is ‘RG6’ so anything labelled this will be fine, this isn’t to be confused with a cheap, tacky cable which is branded “RG6” is the UK. You may across 50 Ohm coaxial cable, this is most commonly used for analogue CCTV cameras and 300 Ohm coax. Avoid this and choose the 75 Ohm cable.

 

Coax Cable Sizes

 

There are lots of different coaxial cable sizes, below we discuss the most common types used for Sky, Freeview, Freesat and communal TV systems. There are a few things that define what cable size will be used but this mostly has to do with cable length when installed. The smaller the cable size the greater the signal losses over distance. The number before the cable type represents the centre conductor size.

 

0.65mm Coax Cable / 65 Cable 

To smallest of all the coaxial cable sizes is 0.65mm cable.This is most commonly used in a pair to form “shotgun” satellite cable for Sky+,Sky Q, Freesat+ and other satellite PVR’s which require two separate LNB connections. Being the smallest of cable sizes, it should only be used for short cable lengths, nothing really above 25m. It will typically lose around 5dB at the highest used frequency every 10m.

 

1mm Coax Cable – 100 Type Cable 

By far the most common and the type and the size that most people will be familiar with, that is nearly always used for domestic TV aerial/ satellite systems is 1mm coaxial. This is the cable that most equipment is designed to take, so for connections into TV wall plates, LNB’s and aerials will almost always have 100 type coax cable in mind. At the highest frequency 1mm coaxial cable will lose around 3dB every 10m so for extra long cable runs, like in communal TV systems backbones you may want to consider a larger cable size.

 

1.25mm Coax Cable – 125 Type Cable 

The next coaxial cable size is 1.25mm cable. This almost always used in communal TV systems to overcome signal losses on long cable runs. 125 cable will typically lose around 2.5dB per 10m at the highest frequency so you can for it to be a worthwhile upgrade over 1mm coax you would need a long cable length. When you get to this cable size normal screw on type plugs start to become unsuitable and you should consider using compression and crimp on style plugs instead. Also when you get to this cable size and above it isn’t suitable for terminating into wall plates, LNB’s, aerials etc.

 

1.65mm Coax Cable & Beyond 

The next cable size above is 165 coaxial cable. I’m sure you know where I’m going from here so I’m not going to list anymore coaxial cable sizes, although there are more. The reason being when you get higher it would be more suitable to install fibre optic cabling instead. 1.65mm cable is pretty much used exclusively in communal TV system and CATV systems. It has a signal loss of around 2dB at the highest frequency. With cables this size and above it can even be difficult to get crimp on plugs to fit well so I would advise installing compression plugs instead.

 

Single Screened Vs Double Screened Coax Cable

 

I already touched upon this is a section above but if you come across the terms single screened and double screened coaxial cable, always opt for the latter as it is much better. The difference between the two is whether or not the cable has a screen and braid or just a braid. Single screened cable will lose far more signal over distance than double screened and it is also more susceptible to pick up interference. It is actually quite difficult to purchase single screened coaxial cable for TV systems nowadays, but it used to be very common. Single screened cable is only ever “suitable”, and I use that term loosely for radio and TV aerial signals. It is completely unsuitable for satellite signals which use higher frequencies and the signal losses on the cable will be astronomical.

 

If you ever come across a single screened cable called “Low Loss” cable, don’t be fooled by it. It most certainly isn’t.

 

Triple Screened Coaxial Cable 

There is actually a triple screened coaxial cable on the market called HD100. The extra screen is on top of the cable braid. Although the performance on this cable is superior, I personally think that this is overkill and not worth the extra expense. I’m not the only one as the popularity of this cable type hasn’t really caught on.

 

Shotgun Cable – Twin Cable 

Another term you’re likely to encounter is “shotgun” cable.This is two coaxial cables joined together which makes installation easier as you would usually install a twin cable to satellite PVR’s like Sky+ and Sky Q boxes. Shotgun or twin cable is also commonly referred to as Siamese cable on the other side of the Atlantic for obvious reasons. Most shotgun cable that is installed is a twin 0.65mm coaxial cable which is suitable for short cable lengths and is handy as it can fit through a 10mm hole. There are twin 1mm coaxial cables on the market which are suitable for longer runs.

 

Foam Vs Air Spaced Plastic Dielectric Cables 

There are different types of dielectric materials used for coaxial cabling. The most common are foam filled (my preference) and air spaced, which uses plastic dialectic to maintain the separation between conductors, a common type of the latter is also called honeycomb cable. Although both types work well in terms of performance foam is becoming the norm as it doesn’t kink as easy as the air-spaced cabling.

 

Multi-core Cable – Trunk Cables 

If you’re installing a communal TV system you may find that installing a multi-core cable instead of a separate 5 cable backbone will really speed up installation. Most multi-core coaxial cables are 5 coaxial cables,each coloured different for the four satellite bands and terrestrial TV & radio. These usually also contain a 4mm or 6mm earth cable which makes installation even easier. You can get all different types of multi-core cables but types with 1mm or 1.25mm coaxial inside are very common.

 

RG6 Coax Cables

RG6-coaxcable

 

The original RG6 standard determined RG6 as a coaxial cable with a solid copper centre conductor, a plastic air spaced dielectric with an aluminium screen shield and braided copper. The performance of this cable was quite good but the big downside with using dissimilar metals for the cable screen and shield is that the inside was prone to rusting with one metal attacking the other, particularly when installed outside.

 

I would however be very wary of called branded or marketed as “RG6” as the modern equivalent is far inferior in terms of performance. It is cheap to buy which is why some people use it. It has a solid copper clad steel centre conductor with a foam filled dielectric and aluminium.

 

CCS & CCA – Copper Clad Steel & Copper Clad Aluminium Cables 

One way of getting the cable cost down is to reduce the amount of copper inside the cable. This is where Copper Clad Steel & Copper Clad Aluminium cables come in. Although you save money, you lose out considerably in terms of performance so I would opt for all copper conductors instead if the budget allows it. The steel conductor in CCS is prone to rusting over time and the steel conductor doesn’t have it very good current carrying capacity. As there is a considerable voltage drop with cables lengths exceeding 30m using a CCS cable for satellite LNB connections is not a good idea as the voltage drop could cause issues with the LNB switching.

 

Benchmarked Coax – CAI Approved

 

The CAI do excellent work in helping installers determine good quality parts and components, but in my opinion the have gone backwards in coaxial cable certification. It used to be that the only cable that was approved was a coax cable with all copper conductive elements, but they also have benchmarked some CCS cables notably the Televes SDK110 Plus cable. Although they are always changing the certification guidelines and the CCS cables are suggested for domestic use only, I think that the only benchmarked cables should be all copper conductor coaxial cables.

 

SDU VS MDU 

When you see the terms SDU and MDU, these stand for Single Dwelling Unit and Multiple Dwelling Unit meaning domestic and communal basically. This means that cable that is certified for “MDU” use is suitable for both domestic and communal installations but not the other way around.

 

LSZH Coax 

If you’re going to be installing lots of internal coaxial cabling you should install LSZH coaxial cabling. LSZH stands for Low Smoke Zero Halogen which means in the event of fire the toxic fumes given off from this type of cable is far less than other types of coaxial cabling intended for outside use.

 

Best Coaxial Cables For Sky, Freesat & Freeview

 

Finally, we get to the part of the blog where I actually recommend cable types for TV systems. I’m just going to bunch a whole bunch of cables here as they’re essentially the same cable made by different manufacturers.

 

Best Coax Cable – Webro WF100

Webro-WF100

 

Webro WF100 is the cable I use for all of Smart Aerials TV aerial installations. Although I will occasionally use a shotgun cable for satellite over short distances Webro WF100 is undoubtedly the preferred option. WF100 is a foam filled coaxial cable with all copper conductors, so solid copper centre conductor, copper braid and copper shield. Webro HD100 technically is a better cable with its extra cable screen but in my opinion,  it isn’t worth the extra expense.

 

WF100 can also be purchased as a twin cable, perfect for satellite dish installations or for wiring/ rewiring TV systems.

 

Other All Copper Coaxial Cables – PF100 – CT100 – NX100 

I have also included modern CT100, PF100 and NX100 as almost equally good to WF100. To be honest they are so similar I wouldn’t worry if you have one instead of the other.

 

Best Sat System Cable – WF100 – WF125 – WF165 

If you read the early part of this blog you will see I talked about the different coaxial cable sizes, this depends on the cables lengths that you’re installing. I again rate Webro the highest so if you’reinstalling a communal IRS system, I recommend WF100, WF125 and WF165 as suitable cables for doing so. You may even want to get these a multi-core cable to assist with the installation.

 

Coaxial Cable Questions? Post Them in The Comments Section

 

If you have any questions arising from this blog or just want to drop me a message, please do so by LEAVING A COMMENT IN THE BLOG COMMMENT SECTION BELOW. I appreciate your patience when you do so, I will get back to you, but I also have a business to run so I can’t always give the help to people that they want. Please DO NOT CALL OUR TELEPHONE LINES, these are reserved for customers only and we do not have the ability to be able to offer free advice over the phone, sorry about that. I definitely do not have the time. Please also DO NOT E-MAIL OR FILL OUT OUR CONTACT FORMS, again these are reserved for customers only. Again, we do not have the ability to answer all the separate questions we get asked and you will either not receive a response or receive a response asking you to post your enquiry in the blog comments. By posting your question in the BLOG COMMENT SECTION below also everyone reading the blog in the future will get the benefit of the question asked and the answer given. Also, I won’t have to answer the same questions a hundred times.That being said I will help where I can.

 

Until next time,

 

Tom

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