ARLA/CLUSTER: Implementação do controlo da frequência dos "beacon" por GPS na Austrália

[João Costa > CT1FBF]

WIA beacon grants

Grants are available to upgrade VK beacons on the bands 2m and up by
implementing GPS locking of their frequency.

The *Wireless Institute of Australia* (WIA) and *Alan Devlin VK3XPD* have
joined in a collaborative arrangement under the new WIA Grants Scheme to
provide beacon owners with funding of up to $200 per beacon, or beacon
group, to upgrade their beacons with GPS frequency locking.

Anyone who’s been around the VHF-UHF bands for a few years understands the
purpose of beacons. The original concept was to provide a ‘propagation
indicator’ to distant stations. Once they became established, operators
within a beacon’s ‘local’ area used them as a ‘reference’ signal: “Is my
gear working? Ah, there’s the beacon�.

Searching for a distant beacon that may be a weak signal is frustrating if
it’s not on its nominated frequency, or very close to it.

Most VK beacons derive their output frequency from a crystal oscillator and
multiplier chain, or from a phase-locked loop system locked to a crystal
oscillator. These schemes inevitably have an issue with drift and therefore
accuracy. The problem gets progressively worse the higher the output
frequency. It becomes critical on the microwave bands.

The development of weak-signal digital transmission modes that necessitate
high frequency stability in transceivers has motivated many amateurs to
install GPS locking of their rigs, leveraging the high frequency accuracy
and stability of the GPS satellite technology.

Alan Devlin VK3XPD saw that this development necessitated improving the VK
beacon network, so that their functionality matched what beacon users were
doing. Alan put a proposal to the WIA to encourage beacon owners to
implement GPS locking, which was accepted earlier in 2014. A total of up to
$5000 is available, $2500 each from the WIA and VK3XPD, for the exclusive
purpose of funding GPS locking upgrades for VK beacons operating on bands
from 144 MHz up.

Beacon owners Australia-wide are encouraged to apply – and the sooner, the
better. This is available to all-comers – individuals, clubs and groups,
members and non-members, WIA-affiliated, or not. The initiative ends on
1 June 2015.

GPS locked beacons better serve their function as a propagation indicator
because you know exactly what frequency it will be on, but they also
provide local amateurs with a highly accurate frequency reference.

The terms and conditions of the Grants Scheme are set out in Alan VK3XPD’s
article published in the August issue of Amateur Radio magazine. A copy of
his article is now available on WIA website at www.wia.org.au

So, how’s progress ?

Up to mid-September, applications had been received from beacon owners in
VK3, VK4, VK5 and VK7, which cover some 15 beacons in total on 2m, 70cm,
23cm, 13cm and up.

Keep those applications coming !



*Roger Harrison VK2ZRH*Wireless Institute of Australia
<http://www.wia.org.au/>
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