HUM.....Where do we start.
1- If you know the technical specifications of your amplifiers you are now using, we can calculcate what will be the final specification at the end of your system.
2- The P/V spec. at the end of your cascade should be N/10+1, where N is the number of amplifier in the cascade. Ex. 22 amp. = 22/10=2+1=3 dB P/V.
3- Now to verify your P/V you need a sweep system. With a cascade of amp. 22 amps. and a good sweep system you should be able to get a +/- 2.dB at the end of a such cascade.
4- Now for C/N improvement. You'll need a good spectrum analyzer and measure the end of your system specifications, which are the following: CTB, CSO and C/N.
5- Let say your CTB is -67.0 dB and CSO should be about the same and yout C/N is 44.8 dB at the end of your system.
6- You can now get all of the cascade amp. to work 2.0 dBmV higher, doing this will improve your C/N by 2.0 dB where C/N spec. will now be 44.8 +2 = 46.8 dB C/N.
7- Doing this will worsen your CTB, which will now be 67.0 dB - 4.0 dB worts or 63 dB CTB.
8- You now have to decide how high you want your C/N to be at the end of your cascade.
9- You should never get your CTB worts than - 55.0 dB. Remember every time you raise the output of all amp. by 1.0 dBmV, you'll get 1.0 dB better C/N at the end of your cascade but CTB will get worts by 2.0 dB.
10- I can also calculat your end of your system if you let me now the spec. and type of amplifier you are using now.
One more thing, the CTB and CSO spec. are also affected by the number of TV channel you are carrying.
Let me know if this OK by you.......
Re: Need 550 specs
Member #: 3359
Registered: 1996-2001
Posted:
1285
Name:
Andy Lamarre
Name:
Andy Lamarre
Company:
Catv Expert
Occupation:
Dir.
Location:
Montreal, Quebec, Canada
Personal:
Ancient
Experience:
~66 years
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