How much energy CATV has at endpoint and how to transfer the signal by air?
时间:04-11
整理:3721RD
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1.Do you know how much energy(dbm) the CATV is in endpoint(user side)?
2.If I amplify it and connect it to antenna, can I transfer the CATV signal(channels) by air and others can receive TV channels by air?
2.If I amplify it and connect it to antenna, can I transfer the CATV signal(channels) by air and others can receive TV channels by air?
There is standard in our country that signal in user end must be >66 dB/uV and <85 dB/uV on 75 Ohm cable.
As a rule signal level is near 70 dB. To transmit it via antenna you need signal level >130 dB/uV. So, you see, you need amplifier gain >60 dB. It is impossible obtain in practic, as narrowband amplifier with such big gain will be not stable.
It is much easier to receive and detect one channel, next pass this TV video signal to TV modulator and amplify after it. You will have near 100-110 dB/uV signal after modulator, and your amplifier will have the gain near 30 dB.
Anyway, such amateur retransmittion will be illegal at any country.
