[OZAPRS] UHF APRS freqs in VK

[Matthew Cook]

Unless you're repeater outputs are within 438.9 and 493.3 then filtering
the 70cm APRS channel isn't difficult.   There are a heap of UHF services
being pulled out of Victoria at the moment and very good cavities and
isolators can be obtained for reasonable prices.

Frequency allocation and band plans seem simple to do, but finding the
right balance between all the different activities and requests for
spectrum by the band police means administering this spectrum is harder
than it looks.  I know what hoops had to be jumped through and buy whom for
the current 70cm band plan, it's not perfect but when personalities get in
the way it's difficult to get a "perfect" solution.

If you've got suggestions on how things can be improved then by all means
fire them into the WIA TAC's in your separate states.

73

Matthew
VK5ZM

On 12 November 2017 at 19:02, Glen English VK1XX <
glenlist at pacificmedia.com.au> wrote:

> Hi Scott
>
> yeah 439.1 which is USELESS DUMB IDEA I EVER HEARD OF , I see it in the
> bandplan.
>
> why ? because it is too close to easily diplex into existing 70cm
> repeater systems that it might have to share with. Whoever came up with
> 439.1 had NFI.
>
> Two problems
>
> 1) requires lots of filtering and or loss to combine with 438-440
> transmitters
>
> 2) Because the digi would need to RECEIVE next door to the 70cm repeater
> transmitter, it will just get knocked over with TX noise unless you
> throw something like 3 x 6" 3/4 wave cans at it.... like no way.
>
> Canberra city is going on 442.975
> Ginini will go on 442.775 , tentatively, barring staying out of the way
> of numerous UHF repeater links..
> Maybe they should go on 12.5k offsets to stay clear. hmm.
>
> 200kHz apart in the same region is far enough that sidebands and spurs
> from one TX (say on 442.775) will not get into the other receiver (say
> on 442.975)
>
> :-)
> g
>
>
>
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