: Hello: : I have a 16-element circularly polarized antenna for 440-460MHZ. I was going to build an interferometer, but someone told me that it was very complicated. I'm still shopping for a receiver. Does anyone know how I can build a basic telescope with which I can do a galaxy survey? Or resources that may be useful? Any help would be VERY much appreciated.

An interferometer requires multiple antennas, spaced over some distance, which simulates a larger antenna equivalent, in diameter, to the spacing of the fartherest spaced antennas in the array. You not only have the expense of multiple antennas (although, I suppose it could be as few as two antennas) but the antennas must be *very* accurately aimed and driven (unless you fix the antenna's positions and allow the sky to "drift" past the aperature of the antenna). The other major issue is getting the signal from each of the antennas *in the proper phase with one another* (*very* important), detecting the signal and sending the data to some sort of recording device (chart recorder, computer program, etc).

Such an interferometer is do-able, and can be both fun and a learning experience :>) I built one while in college using four 144MHz yagis spaced over a 30-foot radius...it did work, but the beamwidth (and, therefore the resolution of the telescope) was pretty broad. I could detect gross features but nothing more. Offhand no suggestions for sources of information come to mind, but I will look in my library and see if I can come up with titles. There is, I believe, a company in Florida that sells equipment (including kits) for amateur radio astronomy...I'll see if I can find an address.

Good luck!

• Re: Radio telescope project-PLEASE help - Kate/">Kate - July 21, 1999 - 15:55 UTC
  • Re: Radio telescope project-PLEASE help - bobmay - July 22, 1999 - 02:21 UTC