USB everywhere?

Discussion in 'C4 - HF Matters' started by Richard Lamont, Oct 4, 2015.

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  1. Richard Lamont

    Richard Lamont New Member

    For some reason lost in the mists of time and irrelevant for decades, we use LSB on the 1.8 MHz, 3.5 and 7 MHz bands, and USB from 14 MHz up. We also use USB on 5 MHz for good reasons.

    There would be several advantages in making USB the standard everywhere:

    1. The VFO knob will work the same way round all the time, i.e. clockwise to reduce audio pitch. This would be an improvement in ergonomics.
    2. No need to remember to switch sidebands when using data modes, where USB is now the norm.
    3. Better compatibility with non-amateur users in shared bands
    4. A simple positive 'frequency shift' relationship between modulating frequency and radiated frequency, without inversion, making mental calculations easier.
    5. Simplicity and economy in transceiver design and manufacture once LSB becomes superfluous.

    Implementation: clearly it would be a mess if we had any kind of gradual changeover with people using a mixture of sidebands. It would be necessary to get worldwide IARU agreement for a 'sideband switchover time', possibly 00:00:01 UTC on January 1st in some future year, and give it months of advance publicity.
    Paul Gaskell G4MWO likes this.
  2. g6jyb

    g6jyb Moderator Staff Member

    Certainly ambitious, but actually not a bad idea:)
    In the RSGB/IARU-R1 band plans we have a guidance note for traditional use, but am aware there is some USB use in lower bands.
    Your Point-3 was why 5MHz is USB in the UK


  3. Terry-GW0EZY

    Terry-GW0EZY New Member

    Your logic for "USB everywhere" is spot-on. I'm sure the manufacturers would be happy with the simplification! Just some thoughts on why we are where we are:

    My understanding of the "USB above 10 MHz; LSB below" convention for amateurs originates from the early days of home brew SSB (USB) filters at 5.5 MHz that permitted easy construction of a dual band 3.5 and 14 MHz Tx/Rx with a single 9 MHz VFO and additive or subtractive mixing (9-5.5 = 3.5 MHz LSB; 9+5.5 = 14.5 MHz USB). Same with later commercial 9 MHz SSB (USB) filters and a 5.5 MHz VFO. This simple technique is still valid for the small group of home brewers.

    Also, some Dx nets operate exactly on band edges (e.g. 3.8 MHz LSB) hoping that their filters are good enough to reduce out-of-band emissions above 3.8 MHz. I guess the idea is to attract calls from Region 2 amateurs where the band extends to 4 MHz.

    60m is a very recent exception, mainly to fit with military + army cadet transmissions (exclusively USB).

    73 Terry
  4. Robin G0GNE

    Robin G0GNE New Member

    As a military radio fan I think this
    Is a great idea.
    Robin VMARS member
  5. gw3fsp

    gw3fsp New Member

    Personally I think there are far more important matters that need dealing with than enforcing USB only on the HF bands, I use both, have always used both since I have used HF, As for Military equipment all my Clansman kit is now LSB/USB very simply and cheaply done as long as you can use a soldering iron, as for the 5Mhz band why would you want to talk to the Military and/or Army Cadets?, they would be on exercise and far too busy for a QSO with us.
    Leighton. GW3FSP.
  6. Peter Chadwick

    Peter Chadwick New Member

    I agree with GW3FSP that there are far more important matters to consider, one being a co-ordinated response from national societies on dealing with DQRM (Deliberate interference). Another would be longer term expansion of 10MHz in the HF direction. The incremental cost of providing LSB these days is very little. According to various RSGB Handbooks, LSB below 10MHz was the result of a CCIR Recommendation, although I have never been able to find it....9MHz USB minus 5 to 5.5 is still USB, while 9 MHz USB plus 5 to 5.5 is still USB. Twice 5 to 5.5 minus 9MHz is 160m LSB: three times 5 to 5.5 minus 9MHz USB is 7 MHz LSB, and this principle applies to other bands: the principle was used in a some designs in QST in the 1950s. The first Central Electronics phasing exciters produced SSB at 9 MHz.

    the changeover would take at least one generation of amateurs to be fully implemented, and doesn't really gain anything in Spectrum Engineering terms.


    Peter E. Chadwick G3RZP
  7. Richard Lamont

    Richard Lamont New Member

    I agree that there are more important things. However there was a call for ideas for C4 on this forum, and so far this is the only one offered! The mixture of LSB/USB is not a major problem, but it's a historic anomaly and it could usefully be tidied up.

    Inter-working between cadets and amateurs does occur on 5 MHz. I've heard it. It's specifically provided for in Note (g)(v) to Schedule 1 of the current Full licence terms. However USB is the norm on 5 MHz in every country that already has it, so it's not really much of an issue here. The anomaly exists only on 1.8, 3.5 and 7 MHz.

    I agree that extension of 10 MHz longer-term should be one of our first objectives. (This is one of the things Peter and I discussed over a pint on Friday at the RSGB convention.) That objective has to compete with others to squeeze through the ITU bottleneck. (ITU conferences can only spend a small amount of time considering amateur matters, so the IARU has to use it sparingly.) However, 'USB everywhere' would require no ITU involvement. It can be done by the IARU itself. I'm guessing that co-ordinated action by national societies on DQRM is also a matter for the IARU, not ITU.

    I don't understand why changeover would take 'at least one generation of amateurs to be fully implemented'. It requires nothing other than a decision by IARU to make the recommendation to use USB everywhere with effect from a specified future date, and subsequent publicity within the hobby between that decision and its implementation. The changeover, if implemented, would happen in an instant. That is an essential feature of my suggestion.

    The suggestion is for a new IARU recommendation, not a hard and fast rule. It would be internal to the amateur service. There's no need to involve Ofcom or ITU. And after implementation, people would be just as free to use the 'wrong sideband' as they are now.


    Richard Lamont G4DYA
    Paul Gaskell G4MWO likes this.
  8. g6jyb

    g6jyb Moderator Staff Member

    For info whilst 10MHz has been in the general IARU-AC Spectrum requirements for some time, it isn't in the immediate term which is focussing on 1.8 MHz (and 50 MHz) Future Agenda items for harmonisation/expansion at present.

    At a WRC, any new spectrum needs 193 countries not only agreeing it at ITU, but you need to make it worth their while even considering it in the first place four years beforehand - which is a serious new challenge. Furthermore if its a UK/European future proposal it needs to get thru 48 CEPT members (who are all Primary Users) first before being raised. HF doesnt exactly get their top priority - One day perhaps but definitely long term. We were lucky to have even 5MHz being considered at WRC (after Cuba proposed it after some bad storms)

    By all means start a separate thread for future spectrum matters...
    (we are getting updates from the current IARU-R3 conference and will see WRC15/19 updates soon, in November

    Murray G6JYB
  9. Paul Gaskell G4MWO

    Paul Gaskell G4MWO New Member

    I concur entirely with Richard Lamont's original and subsequent post, particularly as concerns datamodes. What is probably not immediately apparent is the usefulness of one uniform sideband choice in a the case of disaster/emergency scenario, where interworking of amateur and commercial (and/or military) HF equipment may be necessary (each transmitting in their own frequency band) or where it is necessary to utilise a piece of commercial HF equipment - which is inherently USB, to operate in the 1.8/3.5/7Mhz amateur bands. By the way, in the UK , in the original MoD/RA[Ofcom]/RSGB 5MHz talks way back in 2002, it was agreed that amateur stations could also communicate with Military stations (not just Cadets) and to this end some years ago RAYNET conducted interoperability tests with 2 Signal Regiment on 5MHz.

    Richard is perfectly correct in saying in this last paragraph that the issue is internal to the amateur service and possibly down to an IARU recommendation; having said that, the DX community have just decided to re-define the Q-Code 'QTX' -

    "A redefined Q-code ( QTX ) is promoted to communicate the state of affairs clearly from both ends of the DXpedition circuit. The approach was renamed "DX CHASE: IT TAKES TWO TO TANGO".

    The new meaning of QTX

    When a DXpedition operator clearly spells out a callsign and a number,it simply means that a targeted station should stop transmitting for a specified time period, say 1 hour, and then come back with a retuned method and mind.
    Alternatively, a DXer can send QTX with band and time to a pilot station indicating that a specific DXpedition operator's efficiency and throughput - the rate, that is - has reached a point where the DXpedition operator cannot handle the task at hand, so much so that it all results in a chaotic situation. The DXpedition management folks should then act accordingly to deal with this unfortunate operator.

    The original definition of QTX

    This is the original definition of QTX: Will you keep your station open for further communication with me until further notice (or until.... hours)?
    I will keep my station open for further communication with you until
    further notice (or until....hours).

    The new QTX code was released on exactly the same hour at the ARI DX summit in Rome, Italy and the RSGB Convention in the UK
    ." (Southgate ARC News 12th October 2015).

    This doesn't seem to have passed through IARU?

    I was also under the impression that Amateur Radio was being marketed as a '21st Century' hobby- does hanging on to a convention that covers just three bands and has now been technically superseded, really show that?


    Paul Gaskell G4MWO
  10. G4FSU

    G4FSU Moderator

    I think the idea of USB everywhere is fine. Not that I have a big problem with LSB either. But why wait for the IARU? If you like USB, just use it! There's nothing that I can find in any IARU band plan that says we should LSB below 10MHz - it's purely historical convention (and as Peter says, it's nothing to do with the 9MHz IF, 5MHz VFO thing - 5 minutes with a pencil & beer mat can debunk that). There's certainly nothing in your licence schedule that says you cannot use USB on all bands. I'd rather see the IARU work on other items rather than on something that might actually unnecessarily restrict a mode of operation (LSB).

    Yes, I agree, USB would be better everywhere. Start today!

    73 Ian G4FSU
  11. Richard Lamont

    Richard Lamont New Member

    If we don't wait for the IARU, then we will break the existing de facto standard of LSB on 1.8/3.5/7 MHz. Then we would have a mixture of both sidebands in each of these bands, which would make tuning across them much more difficult as people would have to keep switching sidebands to hear stations. It's much easier to tune if nearly everybody sticks to the same sideband. That's why it's important to make the change in an organised way, worldwide, at an agreed future date, on the basis of some sort of consensus within the hobby. Only the IARU has the capability to bring that about.

    Richard G4DYA
  12. Mario G8ODE

    Mario G8ODE New Member

    Not such a good idea ...there is a lot of kit out there still in use that cant switch between LSB/USB on either side of 10MHz.
    This proposal is nuts and would be akin to asking the UK to drive on the RHS after more that a century driving on the left, just so that manufacturers can make cars more easily.

    As was already pointed out there is no stipulation in the licence as to whether you operate LSB or SSB, but by not following tradition the bands below 10MHz would become a mess with stations old (LSB) and New (only USB) interfering with one another. Modern rigs have so many option Menus ? Buttons so I see nothing wrong in keeping with tradition. In fact what's the real cost benefit?

    Regards the 5MHz band and USB ....this was an experiment.. and the rules clearly laid down only certain frequencies and USB to be used ...which is fine and automatically precludes old kit with just LSB option below 10MHz from operating on this band.

    Better IARU consider, getting a few more HF frequencies or standardising on max TX power to reduce QRM on the HF bands than this proposal

    73 Mario G8ODE
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