Why To Do Shifting Of 550 MHz CATV Amplifier To 750 MHz Or 890 MHz Amplifiers In CATV?

catv amplifiers shifting

What Is CATV Amplifier

sharp amplifiers headend equipment

CATV Amplifier is a equipment which amplify the signal.It is used in Headend as well as in cable tv field.This is boosting device which boost the signal and carry it to long distance in field.It can be also use in headend to amplify the signal received from QAM. This output goes into the different transmitters to send signal in field.There are different kind of amplifiers that work for different frequencies like 550 MHz,750 MHz and 890 MHz. Thus it is also known as Headend Equipment.

Need Of Shifting CATV Amplifiers

Every industry needs to upgrade. Like this cable tv industry needs to upgrade its field amplifiers.We were using the catv amplifier of 550 MHz that is limited to the 67 analog channels. As we all knows number of channels are increasing day by day now we need to use more frequencies.To transmit these new frequencies in field we need to use 750 MHz amplifiers or 890 MHz amplifiers. 890 MHz amplifiers are capable to amplify 106 analog channels.So for digital headend if you are using frequencies more than 538 MHz then you should go for 890 MHz amplifier for better performance in field.

What Is Patch Panel For Digital Headend

headend info book download

Problem In Replacing 550 MHz to 750 MHz Amplifiers

If we are using traditional amplifiers of 550 MHz with 500 series trunk coaxial.Then the amplifier distance is 400 meter.

So if you want to upgrade this to 750 MHz amplifiers having same trunk line.The gain of amplifier here is 30 dB.Then there should be distance of 350 meter between one amplifier to another amplifier.But in our case the distance is 400 meter.Now we need to make this distance small around 350 meter for proper use of 750 MHz amplifiers.This can be done by shifting the CATV amplifiers at small distance.But this process is not so easy.We need to cut the trunk line every 350 meter.So we need to remove small piece of 50 meter.This process is bit expensive also.

Solution of Replacing

Scientific Atlanta have made two types of amplifiers to avoid this problem.These are LE3 and Gainmaker. LE3 amplifier works for 750 MHz while Gainmaker works for 890 MHz.These two amplifier are compatible to replace 550 MHz amplifiers with 750 MHz and 870 MHz.

Both of these amplifiers provide the high gain. LE3 provides 34 dB at 750 MHz. Gainmaker provide 36 dB at 870 MHz.Thus Gainmaker is providing 6 dB more gain this 6 dB gain is distortion free.It means it can accept 3 dB less signal and can provide 3 dB more signal at output.Also it can accept 6 dB less signal input of amplifier.

LE3 amplifier provides 7.5 dB Noise Figure at 750 MHz.While the Gainmaker provides 6.5 dB Noise Figure at 870 MHz. Conventional amplifier at 750 MHz provides near about 9 dB Noise Figure.

The quality of good amplifier is denoted by Low Noise Figure,High Gain and less distortion. Gainmaker And LE 3 amplifiers provides less Noise and less Distortion in signal with high signal output.

Know More About  Digital Headend Equipments

headend info logo forum

Comments



error: Want To Download These Articles ? Go To Books Tab !!!