[OZAPRS] Higher beacon rate HF versus VHF?

David and Justine Olsen davejust at bigpond.net.au
Tue Mar 31 18:57:20 EST 2009


Ray

Some very good points. Lets hope we get more gates and more sunspot too.

David


On 31 Mar 2009, at 17:01, Ray Wells wrote:

> David,
>
> I wouldn't look on your role as playing backstop, I think that's  
> selling alternative networks short.
>
> Provided we can muster up the operators who are prepared to install  
> either, or both, 20m and 40m equipment, knowing it may get little  
> use, I think we can end up with a damn fine arps network for the  
> amateur radio service, to quote Dave Horsfall. Hope I didn't mess  
> up your name Dave, I sometimes do :-)
>
> One of the things amateur operators frequently maintain is that  
> they're available in an emergency. Having spent 20 years as a WICEN  
> region coordinator I have to say that apart from the dedicated  
> handful, that's largely a load of rubbish. However, if we start to  
> take a leaf from our US cousins who actively involve APRS in  
> emergency situations, AND we can provide an almost bullet-proof HF  
> network, we may be on to something that will place the amateur  
> service in good stead. We sure as hell need to try.
>
> We probably have a bit of chicken or egg situation with alternative  
> bands for aprs. What comes first the mobiles or the network. I  
> won't install a ##m Igate because there are no users, and I won't  
> use ##m for aprs because there are no Igates.
>
> It's all too easy to be complacent with the 30m network because we  
> know it works well, with great coverage. (BTW, I logged a ZS  
> station on 30m last night). In years gone by it was only full calls  
> who had access to 20m, 30m and 40m so why not stick with a proven  
> quantity?
>
> The new licencing arrangements that give 20m and 40m access to a  
> new group of potential aprs users has moved the ballpark and we  
> need to adapt. With the potential for higher (than previously)  
> numbers of aprs operators who can use 20m and 40m (but not 30m),  
> the incentive for Igates on the other bands is so much greater than  
> ever before.
>
> Like all things, they take time to evolve. The current discussion  
> on alternative bands for HF aprs has already drawn from the  
> woodwork stations we don't otherwise hear from on this list. There  
> is obviously considerable interest outside of the mainstream few.
>
> David is keen on 40m because he's seen some encouraging results  
> there. Having been a user of HF mobile since 1979 (and HF packet  
> since 1997/8), and having operated HF mobile in the areas of  
> interest to David, in and around the Simpson Desert, I can only say  
> that to take a few prediction charts and a couple of days testing  
> as indicative of the predictability or long term viability of any  
> band is pure folly. That is why I believe we should promote the  
> installation of Igates on both alternative bands, equally, so there  
> is real choice and real alternatives. Many of us have had good long  
> distance results on 20m, 30m and 40m at one time or another.
>
> Ray vk2tv
>
>
>
>
> David and Justine Olsen wrote:
>>
>> No doubt about it Rob, 30m is where most of the effort should go.  
>> Me I will play backstop on 40m
>>
>>
>> On 31 Mar 2009, at 15:14, Rob Heyer wrote:
>>
>>> 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
>>>>>> _______________________________________________
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>>>>>> Ozaprs at aprs.net.au
>>>>>> http://aprs.net.au/mailman/listinfo/ozaprs
>>>>>
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>>>
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>
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