[OZAPRS] UHF APRS freqs in VK

vk2tv vk2tv at exemail.com.au
Mon Nov 13 07:55:23 AEDT 2017


70cm will get a lot worse when we eventually loose 440-450MHz, and 
that's just a matter of time as spectrum gets sold off.

Ray vk2tv


On 12/11/17 19:42, Scott Evans wrote:
>
> Well bandplans come and go and I'm really struggling to get my head 
> around the 5/7 splits just to avoid the LIPD allocation. Ok yes 
> there's some sections of the 70cm band that have dedicated use (space, 
> weak signal etc) another frequency allocation that is just silly, 
> 439.200 being set aside for digital voice (P25, DSTAR, DMR and C4FM) 
> also doesn't quite make any logical sense to me. But what would I 
> know? 🤔
>
>
> On Sun., 12 Nov. 2017, 19:32 Glen English VK1XX, 
> <glenlist at pacificmedia.com.au <mailto: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
>
>
>
>     _______________________________________________
>     OZAPRS mailing list
>     OZAPRS at aprs.net.au <mailto:OZAPRS at aprs.net.au>
>     http://lists.aprs.net.au/mailman/listinfo/ozaprs
>
>
>
> _______________________________________________
> OZAPRS mailing list
> OZAPRS at aprs.net.au
> http://lists.aprs.net.au/mailman/listinfo/ozaprs

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.aprs.net.au/pipermail/ozaprs/attachments/20171113/8358a50b/attachment-0001.html>


More information about the OZAPRS mailing list