scanSydney

Digital listing under construction

Scanned the 480-490Mhz airwaves yesterday and have now added Blaxland to the Vertel's "Teamtalk" NXDN Sydney Metro network
There are linked sites at Sydney Tower, Bondi Junction, Hurstville, Parramatta, Horsley Park, Kurrajong Heights and Blaxland


Grant

Excuse my ignorance in regards to these systems. I am in Victoria but do visit Sydney every year in January. Are these frequencies able to be monitored with a Uniden 996 or Pro96?

If so I will load them up in a bank for next year.

Thanks for your hard work.

C1

Nobody as far as I am aware can monitor these systems (yet)
NXDN uses a voice decoder called AMBE as part of their radio architecture which is not covered by digital scanners (which can only decode IMBE)
Nevertheless that doesn't stop one from getting familar with the "digital signature" each type of system makes
These NXDN signals have become apparent (along with a few Motorola Trbo or turbo sites) in the Sydney metro area over the last 6-9 mths
I have tried to do my best to log them by identifying the sites (hint: listen to the samples of each digital system that have posted on the internet, mainly amateur sites), the likely frequency combinations based on the ACMA entry and the old method of setting aside a bank or two in one of my Uniden 780 scanners and hitting the scan button, noting what frequencies are active with the NXDN or TRBO sound

Grant

While looking for some City to Surf action this morning , I have come across a Motorola TRBO system on 492.925Mhz booming into Blacktown with a regular 60 sec pulse.
ACMA listing showed no-one fits the bill
I thought it might be a australia-wide or nsw-wide rental frequency but still no cigar

Grant

PS My old records showed this frequency as an active LTR frequency until 2007. Possibly Vertel

Only some TV coverage loggings

485.975 103.5 OB TV director
486.075 110.9 carrier
487.9250 no ctss Ch 9 OB audio


Grant

Thanks for the info Grant. I understand what you are logging now.

Cheers, C1
(Greg)

cartman wrote:Nobody as far as I am aware can monitor these systems (yet)
NXDN uses a voice decoder called AMBE as part of their radio architecture which is not covered by digital scanners (which can only decode IMBE)Grant

And don't forget the main benefit of both NXDN and MOTOTRBO is that they use FDMA and TDMA digital transmissions to "technically" allow two users on the same frequency.

Mike

so basically mike its the same theory but on steroids as a pmr channel that has two different ctcss tones....

NXDN and TRBO can do two users at the same time.

I suspect that TRBO with Enhanced privacy can't do it as there needs to be somewhere for the encryption sync info to go in between- at a guess they're using the spare slots for the enc sync.

Someone please correct me if thats wrong.