Replacing a smart meter comms hub

Qyburn

Reed_Richards said:
 I read somewhere that main towers transmit a horizontally polarised TV signal whilst repeaters use vertical polarisation; I don't know if that is true but both the transmitters I can "see" use horizontal polarisation. 

That's true, what we call repeaters are also termed PSB transmitters and only transmit a subset of the full Freeview.  

But I don't think it's true that only full service TV masts are used for LRR. I saw a document from Arqiva to Aberdeenshire Council listing all the locations they proposed to use, mainly existing masts but also some proposed new ones.

As an example here's a planning application for a purpose built mast ..
https://kemnay.info/planning/smart-metering-arqiva/

News article about another ..
https://www.pressandjournal.co.uk/fp/news/aberdeen-aberdeenshire/1923877/plans-lodged-for-telecoms-site-at-lost-to-boost-smart-meter-readings/

Screenshot from the letter, I don't think I can attach the whole thing 

Ildhund

Qyburn said:
... I don't think it's true that only full service TV masts are used for LRR ... I don't think I can attach the whole thing 

Thanks 🙂 You did manage to post a lot more of it here: https://forums.moneysavingexpert.com/discussion/comment/81509258/#Comment_81509258

I did qualify my rash statement a bit: "Arqiva only put SMWAN aerials on their main towers, adding as few as possible elsewhere to meet their agreed target". I wonder how many of those proposed sites now house SMWAN aerials.

Perhaps there's a similar document available from @Reed_Richards' local county council planning dept.  

Reed_Richards

This is the nearest I have come to finding a signal in the right frequency range.  It certainly seems to be a signal that pulses.  I can't perceive any regularity in those pulses but perhaps I only capture a small fraction of them?



422.5 MHz is certainly in the right frequency range (as stated here https://www.smartdcc.co.uk/media/4864/c-work-dcc-media-3613-standard-420-revde-sbch-comms-hub-datasheet-dcc-20.pdf ).  I don't know why I have not seen this signal before, except that this is the first time I have tried after dark.  And even now I can't achieve a consistent result.   

Qyburn

Does the pulse correspond with flashes of the WAN light?

Reed_Richards

No, not at all. 

I'm curious about whether the smart meter ever broadcasts via the WAN other than when requested to report.  If all the smart meters are speaking at once, even to just say "here", it would make for a much noisier environment.  A WAN flash could, I suppose, indicate "signal received" but the flashes actually come more frequently when the signal isn't received, so that seems unlikely.      

debitcardmayhem

My guess the hub polls the receiver to see if there is anything coming in, a bit like wake on lan works, or perhaps not. Maybe the receiver sends an interrupt to the hardware ….
I doubt the hub sends anything until it receives something for its MAC address.