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October 2009
Peter, VK3BFG has worked hard at creating the gadgetry and patching software so that all ATVers will be able to access the DiGiTaL Amateur TV repeater. The system is based on German Digital Video Broadcast kits and off the shelf DVB receivers. Uplinks are both analog and digital, while the downlink will only be digital DVB-T at 446,500Khz (446.5Mhz).

To date there are 2 output channels or streams at 446.5Mhz VK3RTV1 and VK3RTV2, these outputs have multiple inputs, both analog FM-TV and Digital DVB-S (satellite standard definition.)

For retro-grade functionally the analog input frequency has NOT changed and is still on 1.250Ghz which outputs as VK3RTV1 on 446.5Mhz. Inputs operate on a "first in, takes control" between the analog and parallel digital inputs for VK3RTV1 and VK3RTV2.

VK3RTV MUST be transmitting for your Set Top Box or Digital TV receiver to pick up VK3RTV services on 446.5Mhz (446500Khz). Also you'll need to do a manual scan as most receivers skiped over 230-470Mhz when using auto scan, which is assuming your receiver does have a continious RF coverage of 170 - 820Mhz; If not services may not be receivable...

VK3RTV1
Analog input will be on 1250.25Mhz for FM-TV services.
DiGiTaL input may be on 1245.50Mhz or 1278.5 DVB-S format *.

VK3RTV2
Analog input will be on 1283.25Mhz or 10.41 Ghz for FM-TV services.
DiGiTaL input may be on 1278.5Mhz DVB-S format *.

* DVB-S - Digital frequencies listed are proposed, numbers expressed may be rounded up or down by 0.5Mhz

Seperate frequencies for analog & digital are proposed to ease half-duplex operation between users of the old and new technology by simply "stop sending" to RTV for a moment so the other user can take control of RTV. This also reduces interference of stations tuning up transmitters...

Operation:
Typically users will be on each sub-tv channel doing their own thing, sharing the DiGiTaL device without interfering with each other. Viewers just select which sub-channel they want to watch, much like they do for commercial / government TV stations now.

The technology has the ability to have 4 or more sub-channels, there is room to expand but at present there is only 2 channels. Adding extra channels or other DVB services is not easy, there are lots of ancillary equipment and cables to hookup and controls to duplicate for each sub-tv channel as well as technical and operational issues to work through. So far 1000's of dollars from many sources and even many more hours of Peter's limited time have been spent to get these 2 sub-tv channels operational. This is a first for our dedicated amateur TV group and may be for Australia too, so any criticism on service functionally should be tempered with the knowledge that this is bleeding edge technology for professional TV broadcasters let a lone for humble group of amateur TV operators...

Note on 1283.25Mhz use: This analog input to VK3RTV2 has unknown intermittent interference problem since 2007. Investigations are continuing but the interference makes using 1283Mhz unworkable... 1283.25Mhz primary use is for operators East of Mt. Dandenong.

New Touch Tone codes to access the special functions of VK3RTV:

Existing Codes (Circa 2008/2009)
TT0.TT1 = $1A Colour Bar and Tone
TT0.TT2 = $2A Colour Bar No Tone
TT1.TT0 = $A1 Beacon Mode
TT1.TT1 = $11 Digital Signal Report
TT1.TT2 = $12 spare for future use
TT1.TT3 = $13 Analogue Signal Report (1250 only)

New Codes (Circa 2010)
TT2.TT0 = $A2  VK3RTV Shack Camera
TT2.TT1 = $21  spare for future use
TT2.TT2 = $22  Digital Receiver Exit (clear OSD)
TT2.TT3 = $23
TT3.TT0 = $A3
TT3.TT1 = $31
TT3.TT2 = $32

That is all for the moment,
more updates when Peter makes them available.

73's
Gary, VK3KHB

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