[OZAPRS] Higher beacon rate HF versus VHF?

[Ray Wells]

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
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>>
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