Hello LF enthusiasts!
I have seen some books abt Power Lines Carrier of the power companies
in ex USSR. I also had conversation with the specialists in this area of
communication.
I can inform some details...
1.Range of used frequencies 36... 620 kHz.
2.The two-channel duplex system(number of channels - 12 with 4kHz wide),
for example 36-84 kHz(bottom) and 92-143 kHz(top) pairs of frequencies is
used. It is interesting, that at such variant the control frequencies 96
or 136 kHz(!!) are used. The narrow-band electromechanical filters are
applied for this purpose (for controls frequencies).
3.On channels the telephone conversations and (or) telecontrol can be
transferred.
4.Modulation - SSB or FM. Output power 20...100w.
5.Possible distances - up to 100km.
6.The specialists speak, that they have no QRM from Russian Loran,
RSDN or LF/MF broadcasting stations on such channels of communication !(?)
They do not know what this such (can be they the bad specialists? ;-)
But they confirm that this communication via Power Lines "dies" in
Russia and other exUSSR - the equipment is not made any more.
7.The basic QRM of such communication - electrical handicapes in
high-voltage wires ("Crown"), damaged isolators, crude weather and
thunder-storms. But the communication via Power Lines sometimes creates
QRM to other telecommunications!
8.I listened to frequencies of the nearest power companies, but accepted
very poorly (on headphones).
My questions:
- About such communication and QRM from HAMs speaks FCC?
- The similar communication in USA, Canada and Europe is used?
73! Ed RU6LA [email protected]
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