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HF segments allowed for PACTOR-II and PACTOR-III, according to IARU band plan for Region 1, and the PACTOR channels used by SAØM and SA8M S/Y MYJOY.
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The frequency listing follow the Swedish band plan version. PACTOR-II (P2) occupies 500Hz per channel, while PACTOR-III (P3) needs 2400Hz but offers several advantages - like 5 times the speed and improved weak signal performance compared to PACTOR-II (P2).
In below table, the yellow numbers in P2 and P3 columns are representing IARU-supported maximum number of channels serving digital emergency networks using WinLink with PACTOR-II (P2) and PACTOR-III (P3), respectively.
Green frequencies are activated by SAØM/SA8M, orange frequencies may be activated later - if required. The frequencies are center frequencies, offset -1500Hz.
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BAND |
PACTOR-II
bw 500Hz |
P2 |
PACTOR-III
bw 2400Hz |
P3 |
CHANNELS USED BY SAØM/SA8M
#=P3, others=P2 |
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1.8 MHz |
1838-1840 |
4 |
1840-1843 |
1 |
no antenna |
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3.5 MHz |
3580-3600 |
40 |
3600-3620 |
8 |
3595.0, 3610.0#, 3612.5# |
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7 MHz |
7040-7050 |
20 |
7050-7053 |
1 |
7047.5, 7048.0, 7051.5# |
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10 MHz |
10140-10150 |
20 |
n.a. |
0 |
10140.5, 10143.0, 10144.0 |
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14 MHz |
14070-14099 |
58 |
14101-14112 |
4 |
14089.5, 14102.5#, 14106.0# |
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18 MHz |
18095-18109 |
28 |
18111-18120 |
3 |
18106.5, 18112.5#, 18114.0# |
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21 MHz |
21070-21120 |
100 |
21110-21120 |
4 |
21092.5, 21112.5#, 21115.0# |
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24 MHz |
24915-24929 |
28 |
24931-24940 |
3 |
24925.5, 24932.5#, 24935.0# |
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28 MHz |
28070-28150 |
160 |
28300-29300 |
400 |
28120.5, 28305.0#, 28307.5# |
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In spite of the unequalled performance of PACTOR-III (2400Hz B/W) in emergency networks, IARU has chosen to give more space to the less potent narrow band (500Hz) communication systems like PACTOR-II, in the segments recommended for digital traffic.
The time used by PACTOR-III to complete the transfer of a message or photography via radio is 1/5 of the time PACTOR-II will need to deliver the same traffic.
To improve their public service, ARES and similar rescue organisations tend to move their emergency traffic into the "all mode" segments allowing 2700Hz bandwidth. The major population in these segments are SSB phone users, who intensely dislike the competition from digital modes - in spite of the fact that a PACTOR-III signal stays within the same 2400Hz bandwidth as an SSB phone signal. Hence, 2400Hz emergency channels find an alternative home in the IARU band plan segments reserved for 500Hz narrow band modes.
True emergency traffic has priority anywhere in the ham bands, but the emergency networks shall need more 2400Hz channels in dedicated segments marked "priority for digital emergency communication and related training". In particular to advertise the IARU commitment to community and public services. We need it as argument for keeping and perhaps widening our frequency bands.
IARU - VS EMERGENCY COMMUNICATIONS
The present main reason why ham radio exists is, according to FCC rule §97.1:
"Recognition and enhancement of the value of the amateur service to the public as a voluntary noncommercial communication service, particularly with respect to providing emergency communications."
However, the IARU policy has been to discourage automation by minimizing the frequency allocations for digital communication. The probable cause of this standpoint could be the composition of the voting panel, where groups preferring phone, CW and contests may be in majority over those preferring digital modes for public emergency services.
To meet the growing commercial competition in frequency allocations, amateur interests are better served by ham operators using the emission types most suitable for serious emergency communications.
SSB telephony may be useful, but is prone to support grave misunderstandings when propagation conditions are low or QRM is high. For coordinated public service operations the speed and automatic error correcting properties of digital systems like PACTOR III are hard to beat - and the ability to transfer high quality photos is far more efficient than words, when it comes to describing emergency situations.
PACTOR III (in combination with WinLink and AirMail) supports the error free two-way transfer of e-mail text and picture messages via radio and Internet. The system will ensure extremely fast and error free e-mail communication in any emergency network.
The PACTOR radio link can replace any broken landline data connection. Furthermore, it extends the full Internet e-mail service to ships at sea - and to disaster areas lacking any other form of communication system.
Still, the IARU bandplan have only reserved the following space for PACTOR III (and similar digital modes with 2400Hz bandwidth requirements):
PACTOR III CHANNELS (CHS)
| BAND |
FROM |
TO |
KHZ |
CHS |
NOTE |
| 160 |
1840 |
1843 |
3 |
1 |
CHS=channels |
| 80 |
3600 |
3620 |
20 |
8 |
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| 40 |
7050 |
7053 |
3 |
1 |
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| 30 |
n.a. |
n.a. |
0 |
0 |
no digital 2.4kHz channels |
| 20 |
14101 |
14112 |
11 |
4 |
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| 17 |
18111 |
18120 |
9 |
3 |
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| 15 |
21110 |
21120 |
10 |
4 |
SSB phone not allowed |
| 12 |
24931 |
24940 |
(9) |
(3) |
shared with all modes |
| 12 |
24931 |
24940 |
(9) |
(3) |
shared with all modes |
| 10 |
28300 |
29300 |
(1000) |
(400) |
shared with all modes |
Channels in brackets are of limited interest for digital transmissions needing 2400Hz bandwidth. Sharing bands with SSB phone signals shall be a shortcut to conflicts.
The HF bands of most interest for emergency traffic are 160, 80, 40 and 30m - with 20 and 17m standing by. On 80m, the eight 2400Hz channels shine. However, 1 channel each on 160 and 40m, and no channel on 30m is a disaster in itself.
Hence and for obvious reasons, in true emergency situations, the traffic operators must consider the bandplan void - and use any frequencies required.
However, to prepare and train network members for future emergencies, frequencies are needed in band segments approved by IARU for 2400Hz digital modes. To allow high speed and error free emergency traffic, and to avoid conflicts with SSB phone operators, the hams training for future emergencies would certainly appreciate a minimum of 3 professional 2400Hz quality channels in each of the 160, 40 and 30m band plans.
I am sure the DXers and contesters shall be willing to dispense with the equivalent of three SSB telephony channels per band, to be reserved exlusively for high quality, emergency communication and training. After all, DXers and contesters should be happy to support the emergency traffic, being the main reason for keeping our amateur bands.
Take one example, the world wide WinLink non-commercial network with about 60 voluntary node stations, all ready to transfer high quality, error free documentation, e-mail and photos - using PACTOR II and III - to and from disaster areas including vessels at sea, in direct radio connection with emergency centers or via the Internet e-mail system. This network alone will motivate several high quality 2400Hz digital channels per band.
Most of the nodes in the WinLink network are equipped for the use of the 2400Hz PACTOR-III in emergency traffic and related training. It goes without saying that in bands where IARU offers 0 or 1 digital channel with bandwidth 2400Hz or more, the IARU bandplan has lost whatever authority it might have had. The emergency networks will - by default - design their own bandplans where the IARU failed. The credibility of IARU planning may suffer.
PACTOR RELATED LINKS
 IARU Bandplan R1 HF 2009
PACTOR
WinLink
AirMail
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