At 03:48 PM 10/18/2006 -0400, Tom Clark, K3IO wrote:
You might be interested in the SRT (Student Radio Telescope) activity initiated by the Haystack Observatory. Take a look at http://www.haystack.edu/edu/undergrad/srt/index.html. It is based on a 7' (or larger) TVRO dish and the web site contains technical details and suggested projects. About 100 high schools and colleges and a few intrepid amateurs have made SRTs. All the hardware and software for the SRT is open source. Also note the SRT bulletin board at http://www.haystack.mit.edu/edu/undergrad/srt/forum/.
For folks who want to purchase SRT hardware, check out http://www.cassicorp.com/; however I note that the last time I checked with Cassi, their delivery times were ~6 months.
CASSI makes a nice az-el antenna mount and Haystack has also used the Polish Alfa-Spid rotor (VE6JY and http://www.alfaradio.ca/alfaspid.html). Both use DC motors which provides for high torque at a slow, steady drive speed. You might be interested in the az-el positioning controller for ~24VDC motors -- just click on "Upgraded Ground Controller" at http://www.haystack.edu/edu/undergrad/srt/receiver/Downloadable_Resources.h
tml.
While there, also pick up the Functional Block Diagram to get an idea of the scope of the project.
By way of "truth in advertising", I have had a strong professional tie with Haystack and their projects for 35+ years -- especially in VLBI and Geodesy areas (see http://www.haystack.edu/), and I now serve on their Board of Trustees, so don't expect me say anything bad!
- Tom
For those interested in using their large dishes (>7-foot) for radio astronomy, I direct you to the website of the Soc. of Amateur Radio Astronomers (SARA), est. 1971. They have a annual meeting/conference at NRAO Greenbank each summer. http://www.radio-astronomy.org
I've been a member since 1998 and have used my 8-foot dish for RA. I'm planning on a 16-foot dish for 1296-eme/1420 RA for summer 2007 (check my webpage for details). 73's, Ed - KL7UW ========================================= BP40iq, Nikiski, AK http://www.qsl.net/al7eb Amsat #3212 Modes: V - U - L - S USA Rep. for Dubus Magazine: dubususa@hotmail.com =========================================