[OZAPRS] 40m gates

Tue Dec 22 20:24:50 EST 2015

Thanks for your posting, Peter. It set me scouring for information about 
the arrangements in Europe. USA uses frequencies 
<http://www.n0trq.com/hf-packet-frequencies> incompatible with our 40m 
band plan so interoperability can be ruled out.

What I found is that in Europe there is a standard APRS 300bps FSK 
frequency of 7047.6 kHz USB 
<http://robust-packet.net/tipsandtricks/HF-APRS-Frequency-Calculation.pdf> 
(=7051 LSB). This results in a centre frequency of 7049.3. Generally, 
unattended operation is encouraged in the segment from 7047 to 7050 for 
narrowband digital modes.

Robust Packet Radio 8-tone PSK (requiring a special SCS TNC 
<http://www.radios.net.au/pactor-email-via-radio-/modems/scs-tracker-/-dsp-tnc-not-for-email-/prod_873.html>) 
is used on 7047.3 kHz USB 
<http://robust-packet.net/Robust-Packet-Network-Manual.pdf> (with audio 
tone centre 1500 Hz). This results in a centre frequency of 7048.8.

Experimental PSK63, MFSK16 and similar modes for APRS are centred on 
7049.7 kHz. These are available through the Cross Country Wireless 
program APRS Messenger 
<http://www.crosscountrywireless.net/aprs_messenger.htm> as well as 
standalone trackers 
<http://hackaday.com/2013/11/14/long-distance-high-frequency-aprs-tracking-using-the-freetrak63/>.

Now, it is easy to see how these have been chosen. They are exactly 3.1 
MHz lower than the same modes on the 30m band. The allocations allow all 
modes to be operated independently. In VK, a CW calling frequency 
<http://www.vkcw.net/7050> has recently been established on 7050. There 
is enough of a guard band between 7050 and the suggested APRS FSK300 
frequency as narrow filters are normally used.

These would appear to be good candidate frequencies for VK and perhaps ZL.

Cheers,
Gerard - VK2IO

On 18/12/2015 9:19 AM, Peter VK3TBN wrote:
> Hi,
>
> I note that USA have their APRS gateways around the 7.100 MHz area... 
>  Europe is lower like ours
>
> North America
> 7.0865 general 40 packet
> 7.1010 USB HF skip net robust packet
> 7.1035 LSB HF skip net bbs to bbs
> 7.1030 USB 40mRP network
>
> Europe
>
> 7.0473 USB
>
> Would be nice to have a global system... Particularly for Boats
>
> Maybe we just stay we're we are as region 3 until we get a cross 
> region agreement if that's what we want?
>
> Regards
>
> Pete
>
>
> Sent from my iPhone
>
> On Dec 18, 2015, at 2:04 AM, "Gerard Hill" <vk2io at amsat.org 
> <mailto:vk2io at amsat.org>> wrote:
>
>> Hi Matthew,
>>
>> That is the bandplan for ITU Region 3 (our region) and as you say it 
>> has narrowband modes from 7030 to 7040 unlike the WIA bandplan that 
>> has CW within this segment. It would be worth clarifying this with 
>> the WIA TAC (Technical Advisory Committee). I expect they'll say it 
>> is for harmonisation with IARU Region 1 
>> <http://www.iaru-r1.org/index.php/documents/Documents/HF/IARU-Region-1-HF-Bandplan--2014/> 
>> and Region 2 
>> <http://www.iaru-r2.org/documents/explorer/files/Plan%20de%20bandas%20%7C%20Band-plan/R2%20Band%20Plan%202013.pdf> 
>> that have CW up to 7040 then narrowband digital modes from 7040 to 
>> 7050 then wideband digital modes (and SSB) from 7050 to 7060.
>>
>> As for increasing awareness of the frequency change, promotion on 
>> this mailing list, WIA broadcasts as well as the outlets you mention 
>> would go a long way towards saturation coverage. Advising users of 
>> the 7040-7050 segment about the change in mode will be a step towards 
>> seeing it freed for digital modes. I know of one daily net that has 
>> already moved from 7045 to a frequency in the SSB segment. There are 
>> more - it just takes time.
>>
>> Considering our new bandplan, are there other 40m APRS users around 
>> the world that we could harmonise with?
>>
>> Cheers,
>> Gerard - VK2IO
>>
>> On 16/12/2015 11:29 PM, Matthew Cook wrote:
>>> In reading all three docs it appears that the latest WIA 40m band 
>>> plan has followed the ITU Narrow Band (NB) DX recommendation 
>>> starting at 7.040, which still has NB modes listed down to 7.030.  I 
>>> wonder why, this seems half baked at first glance?
>>>
>>> The 40m APRS frequency has been 7.036kHz (group C tones) for as long 
>>> as I can remember.
>>>
>>> Perhaps some clarification from the WIA can be sought through the 
>>> TAC's as to when/why was this changed.  I know my VK5 TAC well and 
>>> am happy to discuss.   I'm sure there will be further changes to the 
>>> ITU band plans as of the recent meeting of the minds.  For the time 
>>> being it seems sensible to sit tight, ask a few questions and see 
>>> what happens.   The band plans are fluid as was recently 
>>> demonstrated with the 2m and 70cm bandplans having been straightened 
>>> out and previous decisions reversed.
>>>
>>> If the frequency needs to change, then this will need to include a 
>>> national awareness campaign, so information in AR, vklogger, 
>>> faceborg etc in an attempt to get the new frequency out there.  
>>> Otherwise those in the know will move, but those that haven't heard 
>>> will simply think it's closed down... which would be sad.  There are 
>>> a number of rag chewers in the 7.040-7.050 region using SSB already, 
>>> so moving and camping in there will lead to a few cross words.
>>>
>>> Just my 0.022c worth inc GST and since I've got a vested interest in 
>>> helping said Ham in the Riverland get Larry's gate going again on 
>>> 40m and I hate reprogramming 8525/8528 Codans with a passion !
>>>
>>> 73
>>>
>>> Matthew
>>> VK5ZM
>>>
>>> On 16 December 2015 at 02:20, Gerard Hill <vk2io at amsat.org 
>>> <mailto:vk2io at amsat.org>> wrote:
>>>
>>>     Interesting history on the origins of 7036 LSB for APRS. I tend
>>>     to quote dial frequencies for the "standard" 1600/1800 Hz tones.
>>>     The dial frequencies for the six other tone pairs in common use
>>>     are available here: http://aprs.net.au/hf/hf-aprs-frequencies
>>>     <http://aprs.net.au/hf/hf-aprs-frequencies>
>>>
>>>     When it comes to looking for a spare slot in the band its the
>>>     centre frequency that is of interest. This is 1700 Hz less than
>>>     the dial frequency. Looking at the group archives, there was a
>>>     lot of discussion in Oct 2009 about moving away from 7036 to
>>>     avoid QRM. We never did move :) Now we'll have to.
>>>
>>>     The current ZL bandplan
>>>     <http://www.nzart.org.nz/info/technical/hf-band-usage/> has not
>>>     changed since 2013. The segments in 40m are the same as the old
>>>     VK bandplan. Its probably due for a review to fall in line with
>>>     the latest IARU Region 3 bandplan: http://iaru-r3.org/?dl_id=1
>>>     In VK we should follow the VK bandplan (as released in Sep
>>>     2015). Its annoying to have to change frequency, but its going
>>>     to happen so we might as well get established as soon as we can
>>>     when there is more choice of frequencies. Liz VK2XSE, I'm in the
>>>     same boat and will have to reprogram radios - we all will. Now
>>>     to work out what the frequency should be...
>>>
>>>     Cheers,
>>>     Gerard - VK2IO
>>>
>>>     On 14/12/2015 9:19 PM, Scott Evans wrote:
>>>>     The History of HF APRS on 40m stems from our friends in ZL.
>>>>     That was the frequency that suited best for their local
>>>>     coverage and so I just setup there. Now I'm not up to speed
>>>>     with the ZL band plan (or if there is one) but I do recall a
>>>>     problem with the use of digital modes higher up the band.
>>>>     Personally I'd prefer to stay on the frequency I'm on purely
>>>>     for the fact that it's a known frequency for use in VK/ZL
>>>>
>>>>     back in the archives of this mailing list you will find a bit
>>>>     of chatter around 2007/2008 for reestablishing either a 40m or
>>>>     20m network as an alternate for VK standard license class as
>>>>     they don't have permission to operate on WARC bands. After
>>>>     quite a bit of testing between the two bands it was settled
>>>>     that 40m was the better of the two at that time.
>>>>
>>>>     just one thing to remember, depending on the tone pair of your
>>>>     HF TNC/Tracker most use 1600/1800Hz but some older gear (like
>>>>     the Pakratt PK-232) uses 2110/2310Hz this affects your dial
>>>>     frequency. The reference to 7.036 LSB is for 1600/1800Hz tones
>>>>     so your dial frequency is 7.036+/- and if you are using
>>>>     2110/2310Hz like me, the dial frequency is 7.036510 LSB
>>>>     (2110/2310Hz)
>>>>
>>>>     Now I'm not going to confuse this any further by quoting center
>>>>     frequencies like is done with pactor! :D
>>>
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