From now in Hobart, either after the middle of next year in Perth and Brisbane or in 2014 in the other capital city main transmitters will be all band 3. There will be no need or want for any UHF. This will be for about 50 % of the Australian population.
Interesting that the European manufacturer to which you refer does not make a band 3 only log periodic antenna where as the Australian manufacturers use log periodics in their VHF sections, including the band 3 part of combo antennas. This is is interesting since your company has been singing the praises of LPAs for years. Remember that the gain in the European manufacturers' catalogues is 2.1 dB higher than the gains used in Australia because they use dipole as a reference rather than equal sensitivity in all directions in 3 dimensions.
Your favorite European manufacturer does not make any band 3 phased arrays.
When the digital restack occurs in 2014, there will be no need for band 3 and UHF antennas combinations because group A contains channels 6 - 8, 10 - 12 horizontally polarised, which will be used by all main transmitter sites in State Capital cities. Some regional sites will use group A but vertically polarised.
The current sites which use vertically polarised band 3 and horizontally polarised UHF such as Canberra, Manning River, Wide Bay, Gladstone and Goulburn Valley will either go purely group A vertically polarised only or will go UHF horizontally polarised only.
UHF will not need band 3 at all.
Group B 28 - 33 in horizontal and vertical polarisations
Group C 34 - 39 in horizontal and vertical polarisations
Group D 40 - 45 in horizontal and vertical polarisations
Group E 46 - 51 in horizontal and vertical polarisations
All transmitters on a single site will be allocated all the channels of a group and they will all have the same polarisation.
Using antennas where all of the elements are close to the same length and spacing makes them more sensitive to a smaller range of channels than an antenna designed for a wide range of channels.
A European manufacturer's Yagi channel group antennas are made for the following channel groups
E21 - E26 470 - 518 MHz Not used for TV in Australia
E26 - E34 518 - 582 MHz = AU 27 - 35
E34 - E46 582 - 678 MHz = AU 36 - 48
E46 - E69 678 - 862 MHz Will not be used for TV in Australia after the restack
Phased arrays (panel antennas) are designed for Au channels 20 - 75 or 40 - 75 If these antennas removed the X dipoles and used straight dipoles at the correct spacing their sensitivity would greatly increase.
As you can see these antennas do not match our channel groups.
To show the effect http://www.dtvforum....howtopic=101239
The above effect does not apply to Log Periodic Antennas. The narrower the channel range the smaller the LPA antenna. The maximum gain is much less than a narrow band Yagi-Uda.
You should be selling antennas which comply with AS 1417.1(Int)-2011. This standard expires on 24th February next year. This is to give time to rewrite the standard to match the grouping of channels described above. http://infostore.sai...oductID=1452023
. The cost is tax deductible on your business.
Complying with the standard ensures the best performance in Australia antennas must match our widespread use of vertical polarisation, single frequency networks along with our 7 MHz wide UHF channels and our restricted range of UHF frequencies.This applies to all manufacturers selling into the Australian market. This is not the case in Europe or the USA.
Edited by alanh, 03 March 2012 - 04:21 AM.