* Posts by Roar Dehli

9 publicly visible posts • joined 28 Apr 2009

Socket to 'em: It's the HomeGrid vs HomePlug powerline prizefight

Roar Dehli

Re: Crud generators.

Running CAT5 in older buildings is not impossible and can be done if you must. It may take drilling a few holes in a wall or two, but that is easy even in concrete walls. An electrician will do this easily, and the installation will look professional. Besides, CAT5 outperforms PLT so you will have a much faster network. Introduction of noisy RFI generators like PLT is not justified because of the terrible radio interference they create to nearby radio users/listeners. But of course, it is easy to dump the shit on someone innocent like your neighbour who might be a radio user, and then ignore the problem. A very decent way to behave......

Plasma-TV may have a better picture (regarding black levels, which is very black), but in the last few years the OLED or LED TV's have excellent picture quality, so now they outperforms Plasma-TV's. Take a look at the new Samsung 46" ES8005 LED series which is excellent. And they have no RFI problems and uses only 82w (very power efficient). Plasma-TV's uses twice that or more.

Plasma-TV's have huge problems with RFI, especially in the LW-MW and low HF frequency range.

Most of them does not comply with the essential requirements of the EMC directive 2004/108/EC.



Since there are no EMC-standard for RFI emitted directly from the Plasma screen below 30 MHz, the TV industry have ignored the problem, sending these RFI generators onto the market. Below 30 MHz there is only conducted emissions from the primary side of the TV power cable (AC mains), which is limited by EN55013 I believe. But in a test of RFI directly from the Plasma screen, most (if not all) plasma-TV's have strong RFI, even at 100 or 200 feet away from the TV. The videos abowe demonstrates a 47" Samsung plasma at 200 feet (60-70 meters) away from my wire antennas.


Roar Dehli

Re: Crud generators.

These PLT crap RFI "terror"-generators needs to be removed from the market because they create a huge amount of RFI-problems for all radio users, including blocking DAB and FM. They are basically illegal devices that do not meet the essential requirements of the EMC-directive. Also, they do not comply with EN55022 class B limits. Regarding amateur radio as a hobby (as some like to point out as a reason that makes it less important than streaming data or watching a RFI generating Plasma-TV etc.) does not mean that the essential requirements of the EMC directive 2004/108/EC is cancelled. All electronic devices must follow responsible EMC design and meet the essential requiremets of the EMC-directive. And using a CAT-5/6 (preferably shielded) for your "hobby" data-network will solve the problem with RFI on HF completely. PLT is a totally unnecessary device creating nothing but troble (same story with Plasma-TV's). The final decision for FprEn50561-1 is held back by the EU commission EMC-expert that refuses to approv it, because it allows higher levels of RFI than any earlier standard. FprEN50561-1 is basically a flawed proposal that wants to allow 1000 times higher levels of RFI on HF. I say remove PLT from the market permanently ! We dont need it.

EU standardises hamtagonistic powerline network tech

Roar Dehli

LA4AMA - Roar

The real problem is that those regulators who are responsible for the EMC laws in each country does not take action if illegal devices are sold. How can they test everything ? The manufacturers dont care, they put a CE and EN55022 label on the device, even though it does not comply when tested by indipendent test labs. The world is lost in money making and selling cheap electronic garbage that spew out interference, no action is taken and nothing happens. And when the device does not comply to existing EMC laws, they just change the laws to allow more interference, while the correct and responsible thing would be to put their foot down and make the device illegal to sell, withdrawn from the market. Sad but true. It stinks.

PLT chair: UK Radio Society is 'living in a dream world'

Roar Dehli

Re: Corrections.

Excellent posting !

Roar Dehli

Disasterous EMC handling !!

This FprEN50561-1 is just a way for the PLT industry to bypass EN55022:2006.

A very bad idea regarding EMC, and it shows that as long as the industry can make money on poorly designed products even if it creates havoc with the radio spectrum, they are going to run all over HF/VHF radio spectrum users and they don't care at all.

The only responsible solution would be that the national regulators turned down PLT/PLC all the way and remove these products from the market, as they do not pass the already established EN55022:2006. This standard is active from october 2011 and that actually means that most PLT/PLC units are illegal as most of them do NOT pass the EN55022:2006 testing.

The national regulators and the EU are not doing their job in protecting the already established radio spectrum users, they seem to not care. The EU spokesman in this case needs to be replaced with someone who is responsible and understands what he is doing. I can just shake my head as I read the comments above. "Inflexible attitudes" means that the EMC standards should be followed, not adjusted to suit the producers who wants to turn the entire HF/VHF spectrum into a complete wall of radio noise.

Example of PLC noise: http://www.youtube.com/watch?v=KMR4wPDUM9g&feature=relmfu

There is nothing more to say about it........ it is very dissapointing to witness such poor handling of EMC regulations. To allow such poorly designed products like PLT/PLC to even be allowed onto the market is just a big failure.

See what professional EMC technicians write about FprEN50561-1:


Look at page 7, 8, 9, 18, 19.

These EMC experts know what they are talking about ! I see too many postings here that is just nonsense.

Devolo dLan AVplus

Roar Dehli

PLC homeplug radio interference

Yes, there is hard evidence. Look at my test with the Devolo 85Mbps units:


The test is on one of the international shortwave bands, and the units have notches for the amateur radio bands. BUT there is also an increased noise level inside the amateur radio bands increasing the total noise level or "noise floor" on the amateur bands. The notches are not aduqate enough in many cases. But on the international shortwave listeners bands and other HF frequencies occupied by aironautical and maritime HF services the PLC/PLT devices are a BIG radio interference problem. At a distance of around 50 meters away from my house the Devolo units rendered the shortwave bands useless in most cases, totally blocking a lot of the broadcast stations. Amateur radio operators face an increasingly noisy radio enviroment these days caused by poorly designed electronic devices. Of course we are very concerned that intrusion on the HF frequency bands will make our frequencies useless for radio operation. That is also the reason that RSGB are about to take OFCOM to court for not acting against the PLT devices that cause us more and more problems. The PLC technology are a total disaster and I would like to see some better technology that does not cause radio interference problems.

IEEE drops support for rival standard from powerline LAN spec

Roar Dehli

Powerline networks is a noisy technology

Powerline networks is a very bad idea ! The reason is that the data stream is sendt between the PLC units on unshielded mains wiring. Unshielded mains wiring are not designed for frequencies between 2 and 30 MHz (which HomePlug units uses). HomePlug units interfere and "breaks down" licensed radio communications and blocks wireless devices like computer keyboards etc.

EMC-tests has shown that HomePlug units does not meet EN55022 standard, and as such they will be removed from your property if they interfere with nearby radio communications and radio receivers. Huge warnings against this poweline technology have been stated, take a look at what EMC-experts is writing about it:


Ofcom in the UK are also about to be taken to court by the RSGB for allowing this kind of disturbing technology to be sold legally:


My advice is to use CAT-5 wiring or Wifi 2.4 GHz or 5 GHz in stead.

The EMC experts are pretty clear on this issue: technology that blocks huge amounts of the HF-spectrum (which is already occupied by licenced services like amateur radio, shortwave broadcast, DRM, aironautical and maritime HF services) must be abandon.

Roar Dehli


Ofcom fails to sweep away power-line networking

Roar Dehli

PLC should be banned !

I read all the comments posted here by people who do not understand the reality about this issue.

The problem arises when products that does NOT meet well established EMC-limits (EN55022) suddenly are release on the market. My conclusion is that the regulation is not enforced by the authorities, OFCOM are not doing the job they should do ! Their job is to make sure that products who fails the EN55022 limit does not enter the market. The guy who writes about ComSat are forgetting something, what happens when the satellite system fails ? Then you will have to get hold of a ham radio transceiver and an antenna, and then you will make that emergency contact because you don't need a satellite for that. Satellites costs a lot of money, and have a limited life span. But other than the emergency aspect of ham radio the real issue is that no one should be allowed to place products on the market that destroys other services ! Good engineering would never allow this to happen, but in the case with PLC it has happened ! That is evidence that people that does not have the necessary technical skills and know what they are doing is involved in the process of decision making regarding PLC.

The statement about reducing the amateur radio frequencies to 10-20% of the current to allow PLC is outrageous ! That is just like saying "lets reduce the TV frequency area to allow only 2 TV-channels, because I want to use the rest for my broadband connection". PLC and HomePlug in its current state should be banned because it intrudes on an already occupied frequency area, occupied by well established and licensed services like amateur radio, emergency and short wave broadcasting. The ONLY solution is to ban PLC until products that follows good engineering practice is launched that does not interfere with other services !

Roar Dehli


Solwise Piggy 6 multi-device powerline network adaptor

Roar Dehli

PLC home plug adapters do make radio interference !

To Nebulo, Gary:

You say that good powerline products don't emit on frequencies used for communications.

In this area I must disagree with you. I have tested some Devolo Home Plug unit's and found them to emit on frequencies used for AM shortvawe bands etc.. There was notches in most of the amateur radio bands, but there still are some interference here also. Some PLC units have been tested by the Norwegian telecommunication authoroties, but none of the units pass the EN55022 test. EMC reqirements are all going "down the drain" because of "loose" requirements and new EU laws. This is bad news for HF radio spectrum users.

In the video link below you see my test of the Devolo units. I did start transferring of a big file from one computer to the other in my own apartment, then I walk outside to see the range of the PLC interference to the shortvawe band. I start to walk toward my house, and as you can see the interference are severe.

Link: http://www.youtube.com/watch?v=zlJvUwSZqNE&feature=channel_page

In this test you see the Devolo units in standby mode:


And the same test with the Devolo units in transfer mode:


As you can see the radio interference makes it impossible to listen to AM shortwave.

For those who wants to use the AM shortwave bands, this will be impossible with these units in the neighbour house or in a 80-100m radius from the radio antenna.

That is why we shall all use CAT-5 cable for our home networks !

Many radio amateurs are buying amateur radio equipment for maybe £10.000 or more , and then some plastic box costing £40 are wiping out parts of the radio spectrum. This does not make sense !


Roar Dehli