assent
发表于 2025-3-23 11:17:54
Carrier Communication Terminals,minals were designed exclusively for telephone conversation. When remote supervision and control entered the picture at some later date, the first carrier terminals built were again of the single-purpose type and their transmission band was chosen so as to fit into the allocation scheme established for the speech frequencies.
忘川河
发表于 2025-3-23 16:26:18
http://reply.papertrans.cn/23/2222/222177/222177_12.png
grenade
发表于 2025-3-23 20:59:05
ment in electric system operation. Being restricted to power networks, it has a comparatively limited scope. Nevertheless, great efforts are being ex to keep pace with the demands made pended on technical advancement of both power and communication engineering. As in previous editions of this book,
委屈
发表于 2025-3-23 22:47:35
http://reply.papertrans.cn/23/2222/222177/222177_14.png
小教堂
发表于 2025-3-24 04:56:09
Communication Circuits in the Power Network, an appreciably higher mechanical strength. Damage caused by adverse weather conditions is therefore a very rare occurrence. Besides, a power line carrier communication system saves the cost of constructing a separate line.
赏钱
发表于 2025-3-24 06:47:47
http://reply.papertrans.cn/23/2222/222177/222177_16.png
peak-flow
发表于 2025-3-24 12:20:07
Measuring Methods and Measuring Equipment,oximate picture of signal attenuation in the carrier channel. Vacuum tube voltmeters were used to measure the HF voltages in the receivers and in by-pass circuits having no telephone stations connected to them.
不适
发表于 2025-3-24 17:53:58
http://reply.papertrans.cn/23/2222/222177/222177_18.png
坦白
发表于 2025-3-24 21:26:13
Properties of Power Lines in the Carrier Frequency Range,quency. Energy losses, in particular, increase rapidly at higher frequencies. The attenuation of the line is a measure of energy losses. (Appendix 9.5). It is a function of loss resistance and the characteristic impedance of a line.
小臼
发表于 2025-3-25 00:56:37
http://reply.papertrans.cn/23/2222/222177/222177_20.png