Powerline Adapters

[bernardgreen]

but my powerline adapters surely transmit on a much higher frequency than short-wave transmissions. So how do they interfere?

If the transmitted signal was a clean sine wave then there would be no problem other than at harmonics of the frequency.

But it isn't a pure sine wave but a mixture of various waveforms which creates lots of harmonic frequencies.

incidentally, at what sort of distance does this interference take place?

The distance at which the signal can be detected depends on how much RF power is going along the mains cable, how far it is reaching and on how much is being radiated from the mains cables it has reached. I am told that free air leakage from a PLDT system was readable 130 yards from the house it was installed in. No information about the receiving apparatus.

The distance at which the signal becomes interference depends on the sensitivity of the receiver and the strength of the signal the receiver is trying to receive.

 

[mattylad]

Who uses SW, MW and LW these days?

Currently the Nepal disaster is being supported by amateur radio operators on 14.205mhz - I am listening to them.
If they were to suffer from PLT interference then it would make their assistance a damn site harder.

Not that PLT noise from your system would affect them, but even though not in the UK - those that are in the UK suffer from this noise.

I cannot use certain bands that I am entitled through my license to because of PLT that could be 2 miles away. Which is why I dislike PLT equipment.

So just because you do not use the radio spectrum does not mean that others do not.

 

[JBR]

but my powerline adapters surely transmit on a much higher frequency than short-wave transmissions. So how do they interfere?

If the transmitted signal was a clean sine wave then there would be no problem other than at harmonics of the frequency.

But it isn't a pure sine wave but a mixture of various waveforms which creates lots of harmonic frequencies.

incidentally, at what sort of distance does this interference take place?

The distance at which the signal can be detected depends on how much RF power is going along the mains cable, how far it is reaching and on how much is being radiated from the mains cables it has reached. I am told that free air leakage from a PLDT system was readable 130 yards from the house it was installed in. No information about the receiving apparatus.

The distance at which the signal becomes interference depends on the sensitivity of the receiver and the strength of the signal the receiver is trying to receive.

Thanks. That explains things.

I hadn't realised that the problem is RF being radiated from the mains cable rather than from the powerline adapter itself. I know very little about SW radio other than it's requirement of a long aerial. Clearly, the mains cables involved could also be quite long which, I assume, is a factor in the effective transmission of an RF signal.