Dxing is dead? (Hang on, Ken, not for some time yet!!) The 'enemy' in this instance, is Digital Radio Mondiale, in some form or other.
I had the privilege and pleasure of being allowed to attend the HFCC Conference held at the Hilton Hotel, Near Birmingham Airport, on 27th to31st August, as a 1 Day Delegate, as it turned out, to represent the DX Community'. on Wednesday 29th August.
I am indeed grateful to Andrew Flynn and his Committee from Christian Vision (The Organisers) for allowing me, this privilege as a conference, such as this, is not usually open to non registered (i.e. Non Broadcasters) and is also (very rarely) held in the U.K.
Unfortunately it was not possible to find a second delegate 'Day Delegate' despite some considerable efforts by Dave Kenny. The Gathering was held in a large Conference Room, however as this was a working conference, presentations for the whole delegation from 'The Podium' were few and far between. The Delegates were mostly circulating and checking for 'potential collisions' between each other, on the Frequency Bands. (See later about Collisions).
Why will DXing (eventually) be dead or nearly so?
There is a strong clue to this, in Gareth Fosters' Article on Page 7 of Septembers' Communication. As DRM is increasingly adopted, presumably DRM Multiplexes will be re-used at least to some extent, especially outside a Primary Service Area, on Long, Medium and Short Wave. Anyway, what has all this to do with the HFCC Conference?
When some form of DRM is fully implemented (which I am now convinced it has to be, though see last paragraph), having talked to some of the Delegates at this Conference. There will then be no ''Oh, was that a catch'' or ''did I hear or did you hear that Station buried away, under something more powerful', also from somewhere in the 'Burumbalas Republic' hiding away in some African Forest.
Like almost all Digital Media its either heard, at or near 100% or not at all, some very 'critical' listening here. Even traditional things like Analogue Tropical DXing (if they still exist at the time) may also disappear in the 'Digital Smog' caused by the Major International Broadcasters.
As I say, I was privileged to talk to a number of '(hard-)working' delegates including representatives from VT Communications, Engineers from AWR, TWR, Voice of Russia, Ukraine Radio International, Radio Sweden, Radio Nedelands, etc.
The purpose of the conference was to work out how to avoid 'collisions' on the VERY limited Frequency Space, which will be available for the forthcoming B07 Season (mostly only on 7 and 6 Mhz during Darkness hours), this is done largely by using Charts that look something like the Blue Pages of 'Passport to World Band Radio', however they are more comprehensive, taking also into account stated Beam Headings and High Frequency propagational conditions.
Several stations, will be making some unusual moves and one, at least, will be abandoning Shortwave to Europe altogether during this B07 Frequency Season, using Medium Wave only instead. I now know why we will have to have DRM, in some form or other (although I again refer you to the Final Paragraph).
Let is take a simple example, I think I am right in saying that that Radio Nedelands broadcasts a News Bulletin in Dutch at 0900UTC on 5.955Mhz (amongst others) using 500KW, from the Flevo, Base Station in the Netherlands. In theory at least using a DRM Multiplex would enable them to broadcast simultaneous News Broadcasts in 4 different languages, at that time, using only 100KW (Total). We are promised, (yet again!!) that Suitable DRM Receivers will become much more plentiful, by Christmas/New Year (this time 2007-8). Although the availability of DRM, mainly by add-ons to a computer, could be a component in encouraging the younger population, to become interested in Shortwaves, not forgetting that some schools do this, and that this is the 50th Year of the Scouts Jamboree of the Air.
More or less regardless, (maybe, in practice, some would say, this is a bit strong), the Broadcasters must go ahead with 'more' DRM to try and fit everything in and to reduce their rapidly escalating power and associated costs.
I did wonder if a different 'coder' or 'decoder' (sometimes called a 'Codec') could be found. (Unfortunatly I did not think of this issue until after my Day at the Conference). Digital transmissions take up much less bandwith per 'stream' than analogue, but the audio quality (Like Digital Audio broadcasting on Band III and L-Band) is dependant on the allocated Bandwith. However more recent developments in compression technology, such as mp 4 has enabled better audio quality to be possible, BUT higher compression ratios cause the received signal to be more prone to error resulting in random loss of audio.
Apparently 'properly made' receivers, should be able to encode all current DRM Transmission Channels, under present standards to within 10 Khz each with no associated problems, but apparently only at about 20KBPS, unless Codecs are improved, as I have said 4 Simultaneous Channels per Multiplex, producing a quality somewhere between Medium Wave and FM.
The possible future difficulties regarding 26Mhz DRM Tests are acknowledged and indeed they are there, at least in part, to test out the 'theory' that they will be swamped (By Italian CB Transmissions etc?) when the Ionosphere is expected to improve with, hopefully, increasing sunspot counts in the next two or three years.
I was surprised at the amount of discussion amongst delegates, some of which was shared with me, about 'related' matters such as Medium Wave and the recognition that 'codecs aside' here in the U.K. we are well in the lead within Europe regarding the development, use and number of Stations on DAB. (perhaps I have been too critical of the Irish Republic, regarding their slow progress with this).
Believe or not Short Wave is NOT dying and there is still enormous pressure for a space on it. In fact some administrations are now seeking to return to broadcasting on Shortwave, due to escalating costs of Satellite Broadcasting. Short Wave is often more robust at a local level, regarding being shut down, much more expensive to Jam a Shortwave Broadcast than order a local relay to be shut down. (one thinks of Zambabwe, as an obvious example), also of course, many poorer countries must continue to rely on Short Wave for the foreseeable future.
We, with interests, in Short Wave Broadcasting, share, of course, the Shortwave Spectrum with many other users, the World Radiocommunications Conference (formerly the World Administrative Radio Conference) meets again in Geneva from 15th October to 9th November 2007.
I was absolutly delighted to be part of the 'delegation' on the day when Geoff Spells of VT Communications gave a short presentation regarding the requests to be made to this World Radio Communications Conference for additional Broadcast Spectrum on the Frequencies between 4 and 10 Mhz, to become effective on 25th October 2015(!!), (so no hope of any alleviation of the situation, during this Sunspot Minimum) The Spectrum requested on a Co-Primary Basis is as follows:-
(1) 5.000-5.250 Mhz (60 Metres!!!!)
(2) 5.730-5.790 Mhz (Further Extension to 49 Metre Band of 60 Khz)
(3) 9.350-9.400 Mhz (Further Extension to 31 Metre Band of 50Khz)
Well, I think that ends my report, apart from expressing my thanks to all concerned for the extremely warm reception I received.
May I be allowed a comment?
'I wonder if Single Side Band or Compatible Sideband could be re-visited? as a means of partially resolving current problems, with a 3Khz Channel Standard and virtually no adjacent channel interference, within these limits, there would be, at least much less adjacent channel problems (even than with the present Double Sideband System), this was originally proposed in the late 70's by Jim Vastenhoud and the Engineers at Radio Nedelands.
Although 'pushed' by the International Telecommunications Union at the time, the idea was eventually more or less abandoned in the late eighties (I think though, one or two USA Stations still use a variation of it). I am sure, now, with improved technology, that better, more useable receivers using this modulation could be manufactured, this also applying to transmitters.
Its not perfect, but SSB is also good for over-riding rough conditions and the 'tone' can be adjusted at the receiving end to suit the Listeners Ear. This Mode of Transmission has been used by Radio Amateurs for many many years and has proved to be largely very robust. Like DRM I dont think it would be suitable for the Transmission of Music. The Problem is as its not Digital, in this day and age its not 'sexy'!!!!!!'
Ken Fletcher 18th September 2007
I wish to acknowledge the considerable assistance of James Welsh of the British DX Clubs' Propagation Department in the preparation of this Report.
This report may be reproduced or quoted on the understanding that the author and the British DX Club are fully acknowledged.
Any comments or suggestions about this article?
See also www.jameswelsh.org.uk for BDXC Propagation Links