Intersting.
David
> On 15 Oct 2020, at 11:54 am, 'Richard Youl' via TramsDownUnder tramsdownunder@...> wrote:
>
> When on the job I found an AVM signpost discarded amongst the rubbish at South Melbourne depot so naturally took at home.
>
> It still worked, and when I held an AM radio close to it and altered the tuner, it picked up a radio signal coming from the signpost.
>
> So next time Mal is out walking if he has a pocket AM radio, he may be able to check it out if there is one almost within reach 😊
>
> Similarly I detected the tones coming from the transponder of a tram but had to hold the radio almost against it to pick up any sound.
>
> Regards,
>
>
>> On 15 Oct 2020, at 10:33, Mal Rowe mal.rowe@...> wrote:
>>
>>
>> On 15/10/2020 10:47, David Batho wrote:
>>> Would it be some kind of ‘transponder’ for the tram’s location, or to trigger appropriate announcements in the tram as it approaches the stop?
>> I think you are right David.
>>
>> I suspect the thick white discs are new 'signposts' for the AVM (Automatic Vehicle Monitoring) system.
>> I did a search of Vic tenders and they pur out a tender for an upgrade to the old AVM system, last year. It included the following line:
>>
>> "The AVM uses radio signposts (270 on the network) and odometer to locate trams, which are reported as being the last-reported distance (meters) past last signpost, and is shown to Controllers textually, as well as on character-based line maps. Meanwhile there are 1700 stops on the network, of which the system is not aware."
>>
>> So I am assuming these are the new stop based signposts, but I don't know why there are sometimes 1 and sometimes 2 - it could be a roll-out change in progress.
>>
>> My understanding is that the plan was to go to GPS, but it was found to be unreliable in the Melbourne CBD due to high rise buildings.
>>
>> Mal Rowe - observing change
>>
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