Australian Amateur Radio Station
Equipment on 9cm:
- A homebrew transverter based on the Zac Lau no tune design
is used as the basis of the system. This provides a low level
output to the PA.
- LNA is a DB6NT Preamp with NF of 0.73 dB and a gain of 28.4
- Power amp is 2 combined "toshiba" 50 W amps. Homebrew
splitters and combiners are used for ~100 W output.
- Feed is a scaled version of the "RA3AQ" optimised septum
built out of 0.5mm copper sheet
- LO is a homebrew design that is PLL locked to a GPS derived
10 MHz signal through a "VE1ALQ" PLL board
- Initially it was thought that a Rx capability of 3456 MHz would
be required, but as it stands all currently active 9cm stations
have access to 3400 MHz and as such this is currently used. A
2nd LO has been built with appropriate switching to allow Rx in
the 3456 Mhz band.
The dish feed is a square septum feed with a transition to
a round septum and a choke flange to improve dish
illumination. It is a scaled version of "RA3AQ's" feed that
was optimised for 1296 to feed dishes with f/d of 0.39 -
0.45. The feed was built out of 0.5mm copper sheet and
the septum is seam soldered into position.
|Power Amplifier: 2 x Toshiba 55 W modules
The power amplifier uses splitters and combiners etched on "Ultralam 2000 " teflon board. With
100 W carrier for 30 seconds, there is no detectable heating of the board. The amplifers utilise
isolators in the output so a standard impedance matching transformer was built for the
combiners. Because of the isolators the need for isolation of the combiner ports is somewhat
diminished. On the input a wilkinson Splitter is used with provision for an attenuator in each line.
This provides an exceptional Port-Port isolation.
|Audio Clips from 9cm EME:
VK3NX - ECHO
VK3NX AS RECEIVED AT G3LTF
|Sun noise = 11.3dB with SFU = 63
Moon Noise = 0.52 dB @ Apogee
CS / Gnd = 5.0 dB
|List of stations
or working to be on,
9cm EME. (Courtesy of DF6NA)
|EME 2008 presentation
by Peter Blair
on the "Revival of 9cm EME"
Excellent technical info and pictures.
|RW1AW SSB during 2008 ARRL