| VK3NX Australian Amateur Radio Station |
| (9cm EME) |
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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 dB
- 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.
- 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 dB
- 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.
| Dish Feed: |
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.
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.
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 Currently On or working to be on, 9cm EME. (Courtesy of DF6NA) |
| "Eagle PCB Editor" Board Files Input Splitter (Wilkinson) Output Combiner (Transformer) For ULTRALAM 2000 BOARD ONLY!! |
| EME 2008 presentation by Peter Blair (G3LTF) on the "Revival of 9cm EME" Excellent technical info and pictures. |
| THINKING OF TRYING 9cm EME ? READ THIS ARTICLE BY VE4MA. |
| Echo signal |
| RW1AW SSB during 2008 ARRL |