[OZAPRS] Higher beacon rate HF versus VHF?

[Rob Heyer]

Ray, 
Hi, I believe you have made a number of good points in your note.

I don't say much on APRS (OZAPRS) because I have a lot to learn and feel 'we' as amateur's need to hasten slowly on the HF issue; look and learn (good and bad stuff) from those who have made there mark. 

We will have a wonderful safety system for those who need it, if we keep our heads.

Me, I'm working towards 30M and think we couldn't have a better band for APRS than 30M.

For what it is worth!

73's 

Rob Heyer 

IRLP VK2RMP Node No. 6018 (146.850 MHz) 
  APRS - VK2XIC QTH; VK2XIC-4 Bicycle; VK2XIC-9 Car; VK2XIC-12 Portable
  Member - WIA  & IARS
              - SES (Shellharbour City)  
Eat Australian lamb a 1,000,000 Dingos can't be wrong !

--- On Tue, 31/3/09, Ray Wells <vk2tv at exemail.com.au> wrote:

From: Ray Wells <vk2tv at exemail.com.au>
Subject: Re: [OZAPRS] Higher beacon rate HF versus VHF?
To: "Australian APRS Users" <ozaprs at aprs.net.au>
Received: Tuesday, 31 March, 2009, 7:30 AM

Hi David,

You need to remember that your geographical isolation in the middle of nowhere doesn't place you any "further" from an HF Igate, as far as RF is concerned, than if you were in the middle of a large city. And it is feasible (but probably unlikely) that propagation is such that an Australian Igate is the only one hearing US traffic on 30m, and they have lots of it. I regularly receive beacons from two US stations (one of them last night and both the night before), and I gated quite a number of packets from a station yachting around the Caribbean a couple of years ago.

Nobody can predict how far their HF signal will propagate. Prediction charts are just that, predictions. A bit like the weather, and we know how that can end up.

For HF, we have to consider ourselves as a part of the global network.

Discuss away, we all may stand to learn something as a result.

Ray vk2tv

David and Justine Olsen wrote:
> Hi Richard
> 
> My email answer may have seemed a bit short, that wasn't my intention.
> 
> I was just thinking that for HF APRS where the maximum range must surely be limited compared to voice, that a worldwide standard on beacon rates that seems like a good idea in heavily populated areas may not be such a good idea in VK.
> 
> I was just contributing to the discussion that not only arrives at such agreements, but also varies them in the same way as the Wide n.n  change came about.
> 
> 
> David
> VK4MDX
> 
> 
> On 30 Mar 2009, at 20:00, Richard Hoskin wrote:
> 
>> 
>> Hi Dave,
>> 
>> I'm not really asking for agreement.
>> 
>> I was pointing out the recommended mobile HF beacon rate world standard that
>> has been in place for over 15 years, and the reasons why.
>> 
>> We have a very good VHF APRS Network in Australia that is based on standards
>> and cooperation.
>> 
>> Cheers
>> Richard
>> VK3JFK
>> 
>>> -----Original Message-----
>>> From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] On
>>> Behalf Of David and Justine Olsen
>>> Sent: Monday, 30 March 2009 8:12 PM
>>> To: Australian APRS Users
>>> Subject: Re: [OZAPRS] Higher beacon rate HF versus VHF?
>>> 
>>> Richard,
>>> 
>>> I am not sure I agree <snip snip>
>>> 
>>>> this results in a maximum of 7 stations being able to transmit per
>>>> minute.
>>> 
>>> 
>>> You sure? They can transmit all they like. Given the poor Rx success
>>> rate, they aren't going to cause a whole lot of problems if they
>>> aren't heard by anyone.
>>> 
>>>> Lets see, HF APRS increases the coverage area from roughly 200,000
>>>> Sq Km
>>>> using 3 hops to potentially 75 Million SQ KM.
>>> 
>>> 
>>> 
>>> Australia is different to elsewhere most that space has nobody in it.
>>> 
>>> 
>>>> the maximum number of
>>>> stations that can be in a single APRS Gate's coverage area is 70
>>>> stations.
>>> 
>>> I wonder how many times you have seen 70 HF stations on APRS at once,
>>> let alone in one iGate's coverage area.
>>> 
>>> 
>>> David
>>> VK4MDX
>>> _______________________________________________
>>> Ozaprs mailing list
>>> Ozaprs at aprs.net.au
>>> http://aprs.net.au/mailman/listinfo/ozaprs
>> 
>> _______________________________________________
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> 
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