5 MHz bandplan

Discussion in 'C4 - HF Matters' started by Richard Lamont, Oct 13, 2016.

  1. Richard Lamont

    Richard Lamont New Member

    An interim bandplan for Region 1 has been agreed, covering the WRC-15 band between 5351.5 and 5366.5 kHz. It might now be worth considering a bandplan for frequencies above and below.

    This might be more difficult than usual, because of the wide variety of Article 4.4 allocations used in different countries. On the other hand, it only needs to be agreed among countries with 4.4 allocations. Also, we should not assume that these allocations in the UK, US, Netherlands etc will change any time soon.

    For SSB operation, it would help if the bandplan listed the spot frequencies that some countries are limited to, with a recommendation that SSB users should operate either on those exact frequencies or at least 3 kHz away from them.

    It might also be worth trying to get agreement on 5266.5 - 5271.5 for data modes only. Maybe 500 or 1000 Hz max BW, no CW or SSB. This would also help to protect the very narrow weak signal data modes section between 5366.0-5366.5 against SSB splatter and CW keyclicks.

    Richard G4DYA
  2. Richard Lamont

    Richard Lamont New Member

    Another thing . . .

    Since Germany got access to the WRC-15 band, it has been a lot busier. Most stations seem to be sticking to the IARU R1 interim bandplan. A few observations:

    1. Most SSB activity has settled on 5360 and 5363 (dial). Some stations are operating higher and lower and usually causing quite a bit a QRM to narrow modes.
    2. 5367-5360 is very busy with mainly JT65 and JT9. (Most UK stations are remembering to stay below 5358. Good.)
    3. There's quite a bit of CW between 5354 and 5357 as well as at the bottom end. (Most UK stations are remembering to stay above 5354. Good.)
    4. Some stations have misunderstood the bandplan as *requiring* narrow modes to go below 5354.

    The overall amount of activity will only increase as more countries add an amateur allocation. It might therefore be worth doing more in the bandplan to constrain SSB and to give greater priority to narrow modes. I suggest five refinements.

    1. That the lower limit for wide modes be raised from 5354 to 5360 kHz.
    2. That a strong recommendation to use only the spot frequencies 5360 and 5363 for USB be added.
    3. That the range of acceptable bandwidths for each section should have a lower as well as upper limit, just to make it clear that narrow modes can go in the wide section.
    4. That within the 200 Hz BW section, the bottom should be exclusively for CW, the top exclusively for data, with a flexible shared area between the two.
    5. A note encouraging JT users to use JT9 instead of JT65.

    So the bandplan would become:

    5351.5 - 5354.0 CW only (BW 0-200 Hz)
    5354.0 - 5357.0 CW and data (BW 0-200 Hz)
    5357.0 - 5360.0 Data only (BW 0-200 Hz)
    5360.0 - 5366.0 All modes (BW 0-2700 Hz, USB voice on 5360.000 and 5363.000 only.)
    5366.0 - 5366.5 Weak signal narrow bandwidth modes (BW 0-20 Hz)

    Hope this gets some discussion going. Been a bit lonely in this forum recently!

    HNY & 73,
    Richard G4DYA
  3. G3YMC

    G3YMC Member

    Until most countries get the WRC-15 allocation, and the situation is unclear in the UK, there will be a need for CW above 5354. Current activity indicates that the 2.5kHz in the bandplan is insufficient anyway and could be usefully increased regardless of the WRC-15 situation. Sharing it with the various data modes is not a long term solution as some of these are pretty strong and seem to be on for long periods.
    73 Dave G3YMC
  4. G4FSU

    G4FSU Moderator

    Happy New Year!

    At the Region 1 meeting last April although there was some discussion about further sub-dividing the band, it was almost unanimously agreed that it would be too restrictive given the already very narrow band available. It's important that 'all modes' is recognised as meaning that any mode is permissible. Thus, CW above 5354 is perfectly acceptable, as is data. But it must also be recognised that USB is also perfectly acceptable anywhere between 5354.0 - 5363.0kHz.

    5357kHz is a spot frequency in quite a few countries including the US and the WSJT-X software picked it as the default 5 MHz frequency which is why JT65/9 tends to end up there. But 5357kHz is also used for USB in the US and other countries. Personally, I would like to see JT9 used in the weak signal segment from 5366.0 - 5366.5kHz, the only problem is there is no US allocation there as yet. JT65 really is unnecessarily wide for 5MHz; it would be much better if JT9 could be encouraged more, but that said, JT65 in the all modes segment is still perfectly acceptable.

    The UK segments really penalise CW as it's outside our band right now; there's nothing we can do about it yet, but hopefully we will get the the full WRC-15 slot before too long so it should be a short term problem. 2.5kHz is too small for CW, but 12kHz is also too small for SSB and we haven't started on data yet! Somewhere around 4-6 simultaneous QSOs should be possible on CW, somewhat less on SSB, narrow band data can probably squeeze more in, but it's very tight whichever way you look at it.

    The issue of whether to suggest that USB be used only on the 4 frequencies of 5354, 5357, 5360 and 5363kHz was also discussed at length & is quite emotional. Channelisation is an easy and efficient way of fitting in 4 SSB QSOs but there are many who do not wish to be so constrained and that use of the VFO should be also be possible, maybe to move slightly LF or HF of interference etc. Both views are right, so we have to try and accommodate them. The current plan does try to fit in with countries that have 5357kHz as a spot allocation as this allows USB (&/or other modes) on that spot frequency and still provides other USB channels above and below it. It also fits at least partly with the current UK allocation with at least 2 possible USB channels of which 5354 and 5363 probably make the most sense (but nothing wrong with going up to 5355 or down to 5362kHz).

    Region 2 adopted the same band plan as Region 1 for 5 MHz at their meeting at the end of last year, so we also need to be careful to maintain consistency - the worst thing that can happen now is we have an incompatible band plan across regions; radio waves don't care about borders!

    I think one of the most important things we need to emphasise is that the WRC-15 segment should be avoided if at all possible for local nets and chatter if there are other 5MHz frequencies available. Many countries in Northern Europe, ourselves included, have many more frequencies outside the WRC-15 segment which are better suited for this activity & it could take a significant load away from the narrow 15kHz band.

    73 Ian G4FSU
  5. Richard Lamont

    Richard Lamont New Member

    Thanks Ian for an informative and helpful post.

    I didn't know that Region 2 had adopted the R1 plan. That's really good news, and as you say it's a good reason to stick to it ourselves.

    USB channelisation: it's a shame that the C-word brings so many hams out in hives, as if there was some precious skill or advantage in twiddling a VFO knob. If channelisation is such a lousy idea why does every professional application of HF SSB use it? The idea that one can move slightly LF or HF of interference is OK as long as the spectrum you're moving into isn't already in use. On the WRC-15 band surely this will usually not be the case. If it's only a slight move that's required, better to move the RX filter skirt instead. Moving frequency even by 500 Hz will reduce the number of available channels by at least 25%. It will also encourage people to try working at 1-2 kHz from an existing QSO etc., and before we know it the whole WRC-15 band will be as vile as 40m during CQ WW DX SSB. And it won't just be other SSB operators who get buried under the racket. It'll be users of every mode, and the primary user to boot.

    Bear in mind that in the UK many SSB operators have come to really like 5 MHz precisely because spot frequency working keeps QSOs at least 3 kHz apart and now find 80m and 40m pretty unpalatable by comparison.

    It's interesting to note all the complaints about new sources of interference: LED bulbs, switched-mode PSUs, plasma tellies, VDLS2 etc. I get some of these too. But the single biggest source of interference I suffer is from other amateurs, transmitting less than 3 kHz from the station I'm in QSO with. For me, this is the single biggest problem with our hobby. It spoils enjoyment of HF like nothing else.

    73 Richard G4DYA
  6. g6jyb

    g6jyb Moderator

    For info, with respect to...

    "I think one of the most important things we need to emphasise is that the WRC-15 segment should be avoided if at all possible for local nets and chatter if there are other 5MHz frequencies available. Many countries in Northern Europe, ourselves included, have many more frequencies outside the WRC-15 segment which are better suited for this activity & it could take a significant load away from the narrow 15kHz band."
    The March edition of RadCom has the 2017 RSGB Band Plans. The only new feature was for 5MHz, which has had Note-4 added to it:-
    "Note 4: Contacts within the UK should avoid the WRC-15 allocation if possible"

    The RSGB Matters article (just released to clubs etc) which covers this also has other comments re out-of band emissions etc


    Murray G6JYB​

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