Definitely More QRM !

[Andre' Kesteloot]

Hans-Joachim Brandt wrote:

> Dear all,
> in order to convert just words into figures I feel it necessary to describe the
> situation in Germany more in detail.
>
> The german NB30 standard has been rejected by all german radio users and
> radio equipment manufacturers since it has been proposed. For those who know the
> british MPT 1570 the problem is that NB30 allows interfering fieldstrengths 20
> dB higher. But even the resistance of the german broadcasters could not prevent
> the adoption of the NB30 standard. The declared aim of the german government
> and the upper house of parliament has been to give "modern telecommunications
> technologies" a chance. The CENELEC standard on CATV systems covering 5 MHz to
> 3000 MHz has also been aligned to the NB30 limits earlier, at least in the HF
> and VHF-UHF range. (NB is simply a german abbreviation for Nutzungsbestimmung =
> operational condition or regulation. There are other NB numbers within the
> german frequency allocation table.)
>
> A radio amateur living in a house in which cables are operated under the
> conditions of the NB30 and having a half wave antenna 10 meters away from his
> house will have to expect the following calculated S meter readings:
>
> Band, MHz       1,8             3,6             7       14      21      28
> NB30
> dB(muV/m)       37,8            35,1            32,6    29,9    28,4    27,3
> S-Meter         S9 +12 dB       S9 +3 dB        S8      S6-7    S5-6    S5
>
> I hope the table will be delivered in the same order in which I have typed it.
>
> The second line gives the interfering fieldstrength permitted by NB30. The
> situation is bad, especially for QRPers. But all efforts of DARC to prevent such
> a decision were in vain.
>
> Regarding the frequency depending levels of the NB30 it must be stated that it
> will allow VDSL and telecommunication over CATV, but only low-level PLC.
> High-level PLC producing interfering fieldstrengths of 80 dB(muV/m) or even
> more, is not permitted, this being the reason for the SIEMENS company to leave
> the PLC business some weeks ago. ASCOM (who now will supply power line companies
> which formerly had decided to use SIEMENS equipment) has claimed in a newspaper
> interview that NB30 low-level PLC would not enable a bit failure rate
> sufficiently low for 75% of all mains outlets. Therefore PLC becomes more costy,
> less dependable, repeaters are needed etc. The real winners of the german
> government decision seem to be those companies which will operate VDSL over
> telephone lines because they will have no (or only few) problems to meet the
> NB30 radiation levels. We know that in the U. K. the MPT 1570 (the range 1.6 to
> 30 MHz, from December 1999) is also under pressure because its low levels even
> do not permit VDSL operation, but offers much better protection for radio
> services.
>
> The European Commission is also in favour of PLC, because a network independant
> of the telephone net could be used. But after the PLC Forum had conducted a PLC
> workshop before the Commission, where strong opposition by radio users had been
> presented, the Commission is said to be at least unsafe whom to believe. But
> basically the Commission still thinks that a compromise with radio users should
> be possible, and still hopes that a standard would solve all problems.
>
> For the time being, german radio amateurs hope, of course, that this german
> example will not be copied by other nations and that european standardization
> (especially the way being carried out in CEPT SE35) will result in lower
> interference radiation levels, for the benefit of radio services. And we also
> hope that the german administration will be able to effectively control the NB30
> limits throughout the country; otherwise a chaos would develop, no question.
>
> Sorry to report such a situation here over the server.
>
> 73 Ha-Jo, DJ1ZB
>
> Andre' Kesteloot schrieb:
> > Power lines win German support
> > By Reuters
> > March 30, 2001, 11:05 a.m. PT
> >  FRANKFURT--Germany's Bundesrat upper house of parliament on Friday
> > cleared  regulatory hurdles for the so-called power-line technology for fast
> > Internet  access via electricity lines. A statement issued by the economics
> > ministry  in Berlin said three laws setting out the conditions for power-line
> > operations had been approved, clearing the way for nationwide
> > implementation  in the 16 states in due course.
> >
> > The move gives power line the chance of competing with other established
> >  communications channels such as cable television and telephone networks.
> >  Analysts say that by delivering high-speed Internet connections through
> > residential wall sockets, utilities could break the phone companies'
> > grip on Internet access while also offsetting recent losses due to shrinking
> > retail  power margins.
> > Story Copyright C 2001 Reuters Limited. All rights reserved.
> >