Sometime ago Vertel reorganised some of their 490Mhz LTR (logic trunk radio) network sites. I became aware of introduction of LTR at the Airport Hilton but until a couple of days ago I was still trying to figure the correct frequencies and Logic Channel Numbers (LCN).

The LTR trunking site is an interesting one, because it appears all of the QANTAS heavy engineering has moved over to this system and off the 800Mhz Motorola Type II trunk system.

The frequencies and LCN order are as follows:

492.6000 = LCN 1
492.9375 = LCN 2
493.4750 = LCN 3
491.1000 = LCN 4
491.4000 = LCN 5
492.0000 = LCN 6

Regular Echo Base and Tango Base users can be heard on talkgroup 0-01-005. I have heard a number of other users eg 0-01-010, 0-02-008, 0-03-010, 0-04-012 etc.

This site is worth further investigation by those equiped with trunktrackers capable of decoding LTR signals.


Grant

Thanks for the info Grant.

Subsequent to that post I have been able to get around a major issue I had with logging the Qantas and Airport Hilton 800Mhz Motorola trunking sites on a programme called Unitrunker.

A long time I had used an earlier version called Trunker 3.8.3 (using a data slicer) to log Motorola Type II radio data but that option disappeared when the notebook I was using went belly up. At the start of 2007 a scanning friend of mine (who is also a VK amateur) helped me with setting up Unitrunker which runs off a data feed from the discriminator tap listening to the specific site control channel on the 780 Uniden trunk tracker and then via the Unitrunker software on my Toshiba notebook. My main target was and still is the GRN which currently runs under mixed mode 3600 baud. Unfortunately a hum crept into the signal which I was under the impression came from where the lead plugged into the notebook. Although I could hear the major GRN sites near me (GPT, Chullora, Homebush) it effectively stopped from listening to the airport specific trunking sites.

Part of my Unitrunker forward planning for the eventual conversion of the GRN to digital (9600 baud) was to get a desk based digital scanner that could be tapped like the 780. Enter the Uniden 796 which i left with the same chap to do his handiwork on the discriminator tap. Eventually I picked it up but assumed that the hum was still there and didn't connect it up straight away. So I was trying it out a couple of days ago and was stunned to find that I could again decode the distant sites on relatively weak signals and with no hum.

What this means is that I am able to collect a huge amount of radio data on these 2 sites at the airport again. Rather than post ad in finutum I might try to piece together as much as I can and communicate with Bob Bell, as I believe he is the acknowledged expert on motorola trunking at the airport and published his findings. So far I have so collected data that suggests there is at least 600 radios over 35 talkgroups at the QANTAS site. It is much quieter at the Airport hilton which has also a 3 frequency 12 channel TETRA site active as well.

Grant

Thanks for the info Grant. I've also been meaning to organise the LTR stuff in my 996. I do listen to the Qantas and Virgin talkgroups from time to time but i noticed that there was some discussion on Scannsw group about some new airport frequencies being heard on the Hilton LTR. Look forward to seeing what you come up with.

Pat

Even better Pat have a try yourself and let us know. I am Cartman on the SCANNSW forum Site

Grant

VERTEL 490MHZ LTR AIRPORT HILTON
492.6000 = LCN 1
492.9375 = LCN 2
493.4750 = LCN 3
491.1000 = LCN 4
491.4000 = LCN 5
492.0000 = LCN 6

AIRPORT HILTON ARNCLIFFE 800MHZ MOTOROLA TYPE 2
System Id 0a37
At least 36 talkgroups and 304 radios

v = voice
d = data channel (alternates each day)

865.0625 v
866.0625 dv
867.0625 dv
867.6125 v
868.0625 dv
868.6125 v
869.0625 dv
869.6125 v

QANTAS MOTOROLA TYPE 2 800Mhz MASCOT
System ID 6407
At least 35 talkgroups and 610 radios

v = voice
d = data channel (alternates each day)

865.4375 dv
865.9375 v
866.4375 dv
866.9375 v
867.4375 dv
867.9375 v
868.4375 dv
868.4375 v
869.4375 v
869.9375 v

The following site is unscannable and for information only (ie what is sounds like)

800MHZ MOTOROLA TETRA - AIRPORT HILTON
4 slot TDMA 25hz wide signal = 16 channels - 1 data and 15 voice channel

865.6125
866.6125
867.7125
868.7125.