ARLA/CLUSTER: O DX Mundial está se movendo para o Rebote Lunar.? Como obter 300 Watts de um par de LDMOS MRF51P21180R6 em 13cm (2,3 GHz).

[João Costa > CT1FBF]

Is worldwide DX moving to microwave EME?

SARL News reports that, contrary to the myth that Microwave equipment
is too expensive, a modern trend is developing where DX operation is
slowly shifting to the Microwave frequencies where there are already a
lot of Microwave activities in the rest of the world.

Here are the main reasons:
In the earlier days analogue EME required 1 kilowatt of power on CW
with expensive large dishes on 2,3 GHz and 5,7 GHz as operated by the
late Ivo Chladek, ZS6AXT.
HF DX operation depends on conditions in the ionosphere as affected by
the Sun and the sunspot number during the Minimum Solar Cycle, whereas
EME DX is possible daily as long as two distant stations can see the
Moon, except, of course, when the Moon is too close to the Sun.

When the digital era arrived, things started to change on Microwave
EME. There was no longer a need for high power or large dishes. For
example, Rex Moncur, VK7MO, tested a small portable EME station on 10
GHz JT4, using a 77-cm dish fed with 45 Watts and worked Charlie
Suckling, G3WDG, over 17 410 km.
Then he tried a 47-cm dish on 24 GHz and copied W5LUA, but the latter
could not detect the QRP 4-Watt signal.
On 5 March 2014, VK7MO established a new World EME record on 24 GHz
with G3WDG. VK7MO used a 1,14-metre dish with 10 Watts and G3GWGB also
ran 10 Watts into a 3-metre dish. Their equipment was GPS-locked and
could cope with a wider liberation spreading on this band. All this
will also open a new world for townhouse EME DX operation!

As future activity increases on Microwaves, so the manufacturers will
start thinking about producing suitable equipment for the amateur
fraternity.

Although this country was trailing far behind on digital microwave
operation, Alex Artieda, ZS6EME (HB9DRI), put South Africa back on the
Microwave Digital Map. He recently had two-way EME contacts with
several DX stations on 10 GHz as well as 5,7 GHz while using 50 Watts
into a 1,5-metre dish and last year he covered 2,3 GHz on digital.

Alex also wrote a comprehensive article for DUBUS, the German Amateur
Radio VHF/UHF and Microwave Magazine, describing how to obtain 300
Watts from a pair of MRF51P21180R6 LDMOS devices on 13 cm (2,3 GHz).

The South African Radio League