141 MHz regular interferometry with QHA antennas

[David Lonard]

Hello everyone,

I set up the antennas that I used for VLBI in a field with a 30 meter baseline and let the system run for 19 days as a real time FX correlating interferometer.

It works o.k. with very strong fringing dominated by the sun during the day (keep in might that it has a widefield view of the sky) with some fringing at night too with lower S/N.

I've switched to using two 3 element Yagis and will let them run for a week and see what that does. Also, I've purchased two 500 foot spools of coax to get a ~300 meter baseline that will be tried soon as well.

David

[Jim Sky]

Very nice work David. Congratulations.  Not sure why more people do not use 2m for radio astronomy.  

[David Lonard]

Yes, I agree that 2 meters is a great place for radio astronomy. To me, the biggest advantage is that since sky noise is still stronger than ground noise, very high aperture efficiencies are not needed to detect astronomical sources. At 430-450 MHz, ground noise is already a problem, and as one goes higher up in frequency, achieving sky noise limited performance becomes harder and harder. 

David