Many Free to Air satellite TV beginners usually struggle to know the difference between Ku band and C band frequencies. But today I will explain the difference between Ku Band and C band frequencies. I would suggest after reading this, you should also check the differences between Prime focus and Offset dishes. It’s obvious that Satellite communication is used for a wide range of applications like Vsat and Weather Applications but in this explanation I am limiting myself to Satellite TV reception only.
Let us start with the older of the two technologies.
This is a typical C band frequency
Characteristics of C band frequencies
- They only have four digits. You can count them literally.
- The C band frequency range is 3.7 – 4.2 GHz (or 3700 to 4200 MHz) GHz and MHz stand for Gigahertz and megahertz respectively.
- Because of the low frequencies, C band waves have longer wavelengths.
- Since we are talking bigger wavelengths, then a bigger dish is required to receive such frequencies.
- Prime focus dishes are used to receive C band frequencies.
- The smallest commercially available Prime focus dish is 1.8 metres.
This is a typical Ku band frequency
Characteristics of Ku band frequencies
- They have five digits, one more than C band frequencies. This is the most noticeable difference.
- The Ku band frequency range is 11.7 – 12.2 GHz (or 11700 to 12220 MHz) Notice how these frequencies are higher than the C band frequency range.
- Because of the higher frequencies, Ku band waves have shorter wavelengths.
- Shorter wavelengths mean that you need a smaller dish to receive these frequencies.
- Offset dishes are used to receive Ku band frequencies.
- The smallest commercially available Offset dish is only 65cm in diameter. Although you can even get a 30 cm dish. That’s the length of a primary school pupil’s ruler.
Now we are going to get into more details about reading frequencies provided by a satellite TV company. The two frequencies I have mentioned above are supplied by Intelsat 20 satellite positioned at 68.5 degrees east. This satellite has both C band and Ku band transponders. You can receive the C band TV stations by having installing a 1.8 metre Prime focus dish and a separate smaller 65cm dish to receive the Ku Band TV stations. I am currently locked on all the Europe and Africa beam Ku band frequencies using a 65cm dish. There are universal LNB’s that can get both C band and Ku band Frequencies but I have never used one.
Now if a TV station on this satellite was advertising itself it would provide you with something like this:-
11801 V 27500 or
11801 Polarity, V Symbol Rate 27500 or
11801 V 27500 ¾
Whatever method the TV Company uses it’s somehow universally accepted that the first batch of numbers is the frequency. In this case it is 11801. The next thing that comes is the Polarity (either V or H for Ku band) and lastly the symbol rate. Although not needed some TV providers usually provide the FEC Rate like the third freq above. Don’t let this worry you because almost all if not most free to air satellite decoders can pick up the FEC rate automatically. (FEC rate stands for Forward Error Correction rate)
This is another Frequency that may be provided, in this case a C band frequency.
4137 R 5530
Notice how the Polarity is now R. (C band frequencies can either be V, H, R or L)
I will cover Understanding and reading Frequencies, Polarities and Symbol rates from Lyngsat in the near future. If the preceding sentence is not a link then I have not yet covered it.