PLT Device Schematic

[2E1IIP]

Chaps, I am looking for a schematic diagram for a PLT networking device, tried several google searches without success - any ideas?

[cjay]

Chaps, I am looking for a schematic diagram for a PLT networking device, tried several google searches without success - any ideas?

You're probably going to have to sign a heavy duty NDA to get one of those but there may be a way 'round that. If you can find an FCC approval number you might well find the schematic on the FCC website.

[2E1IIP]

Really? Must be some other way, I have a BT unit that I am dissecting at the weekend see what info that gives up.

[cjay]

Really? Must be some other way, I have a BT unit that I am dissecting at the weekend see what info that gives up.

There's a few teardowns on the 'net that will give you the basic chipset details from which you may be able to find a datasheet with a typical application in it, that should give you the essentials.

I gave up looking. Personally, I'd go the FCC route but I think that PLTs are proprietary between brands, I.E. unless they use the same chipset then you're not going to get them to play nicely together. Hence what you learn about one brand won't necessarily give you the information you need about the others.

[2E1IIP]

What I am more interested in is the mains coupling, not yet seeing inside the device I would hazard a guess that it would be some form of isolation barrier with opto-couplers.

[crusty]

Suspect it''l employ a proprietary chip something akin to the ADuM4160 used for high speed USB isolation with a stepped input. Good luck with the research.

[2E1IIP]

Thanks for the info so far guys.

[cjay]

What I am more interested in is the mains coupling, not yet seeing inside the device I would hazard a guess that it would be some form of isolation barrier with opto-couplers.

I think it's usually a transformer characterised for the spectrum used. Worth bearing in mind that it's highly likely the device will be at mains potential all the way up to the ethernet magnetics, I.E. very dangerous.

[Mattylad]

Can I ask why?

Surely you don't want to build one yourself?
Might as well just pick up your radios and throw them in the bin if so

[2E1IIP]

Can I ask why?

Surely you don't want to build one yourself?
Might as well just pick up your radios and throw them in the bin if so

Gosh no, couple of reasons:
I am looking for a way to better filter either the unit itself or design a method of externally filtering the QRM from the device to other radio equipment.
Failing the latter then having better understood the technology, find a way to disrupt the operation of the device.

[Mattylad]

Top idea.

If I find anything I'll pass it on. (assuming I'm not under an NDA for it).

[2E1IIP]

Top idea.

If I find anything I'll pass it on. (assuming I'm not under an NDA for it).

Cheers, that would be great.

[EARSEGPK]

Hi there, If you are attempting to filter PLT/PLC device signals have a look at http://www.audioscientific.com/Circuits ... ls_100.htm scroll down to Circuit 43 - Passive filter cleans up power-line communications.
This provides info on frequency and bandwidths used on early PLT/PLC devices. There are two images, one of which includes a basic circuit diagram. May help to get you going..

http://www.ukqrm.org.uk/ also have info and links relating to regulation and use of PLT/PLC devices.

Possibly the best place for technical discussions on PLT/PLC devices can be found on the forum at http://www.interference.org.uk/forum/

Hope that helps. :-)

- Personally the last PLT/PLC device I got hold of were immediately scrapped for parts. Wiped out most HF and caused nasties all over Air and Marine VHF bands.

[2E1IIP]

Hi there, If you are attempting to filter PLT/PLC device signals have a look at http://www.audioscientific.com/Circuits ... ls_100.htm scroll down to Circuit 43 - Passive filter cleans up power-line communications.
This provides info on frequency and bandwidths used on early PLT/PLC devices. There are two images, one of which includes a basic circuit diagram. May help to get you going..

http://www.ukqrm.org.uk/ also have info and links relating to regulation and use of PLT/PLC devices.

Possibly the best place for technical discussions on PLT/PLC devices can be found on the forum at http://www.interference.org.uk/forum/

Hope that helps. :-)

- Personally the last PLT/PLC device I got hold of were immediately scrapped for parts. Wiped out most HF and caused nasties all over Air and Marine VHF bands.

Cheers for the info, seems my neighbors are having a PLT fest at the moment...

[cjay]

Can I ask why?

Surely you don't want to build one yourself?
Might as well just pick up your radios and throw them in the bin if so

Gosh no, couple of reasons:
I am looking for a way to better filter either the unit itself or design a method of externally filtering the QRM from the device to other radio equipment.
Failing the latter then having better understood the technology, find a way to disrupt the operation of the device.

So if you can't filter the noise out you'll be creating even more RF hash.

Nice.

Last time I checked, deliberately causing interference like that was illegal.

Well done you.