Moon bounce
System undergoing a rebuild
I am QRV on 23 and 13cm EME using a 2.3m TVRO dish. The small dish allows me to work most medium to big stations on CW and using JT65C it is possible to work stations using dishes as small as 2m diameter.
My 23cm system consists of a 200W DB6NT SSPA and G4DDK low noise preamplifier with a measured noise figure of 0.25dB.
The dish feed is an OK1DFC septum polariser rectangular horn.On 13cm I have a 250+W G-PCS SSPA and a G4DDK preamplifier with 0.33dB nf. Again, an OK1DFC septum polariser feed is used to achieve circular polarisation. My initial QSOs on 13cm were made using just 50W!
With these systems I have worked 35 stations on 23cm and 2 stations on 13cm.
I have an Orbitron C10 (3m) dish to replace the 2.3m KTI dish sometime in the future.
2.3m KTI dish for 23 and 13cm EME.
Update 12/10/2008
I am now building an AZ/EL mount with a SPID (RAS) rotor. Although the polar mount served me very well for 3 years, the limitations of the linear actuator (about 90 degrees of GHA per moon orbit) became annoying. Coupled with the limitation of a -10 degree delination, due to the mechanics of the mount, it meant I had no visibility of the sun for measurements between the end of September through the beginning of March. I looked for other ways to move the dish. The SPID RAS is a reasonably strong unit but moves in just 1 degree steps whilst under controller direction from Moonsked. Whilst this is quite acceptable resolution for a small dish, it may become a problem trying to work on bands above 9cm with the 2.3m or even 3m dishes. However, the motor and worm drives of the RAS have almost unlimited resolution, it is just the pulse position indicator that is the problem. Replacing these with 'proper' position encoders, in due course, should overcome this limitation.
Update 11/4/2009
The dish is now on the SPID RAS mount. The following photos show the 'pie tin' choke ring I have added to the rectangular horn feed to improve dish illumination.
Page updated 11/04/2009
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