The gods must have spoken to me directly on this one - I already had the exact SDR enroute from Amazon when I tripped across this article. (I also do astrophotography, and this looks like it would mount nicely on an AVX! ) My question is whether anybody knows approximately what the gain of the homebrew horn shown in this article is? (And would something circularly polarized such as a Helix yield a better result? (Sorry for my ignorance - up to now, "Microwaves" to me meant getting on the local 70cm repeater... --al WB1BQE
Al, in the fifth paragraph of the linked article cited in the OP the author Dave N2LVD stated, "An online calculator showed that a horn of those dimensions would have a respectable directional gain of 17 decibels." 73. John, WØPV PS - I momentarily stopped making QSO's in CW Sweepstakes just to answer this question
Sorry - I worded my question poorly. I was wondering how close something like that could get to the theoretical gain, given some amount of mechanical imperfection. (And in the case of my antennas, Substantial mechanical imperfections... )
When I looked for the dongle and the gizmo, I found that the link in the IEEE online article takes us to the Nooelec device that does not have a bias-T. The dongle with a bias-T provides an easy way to provide DC power to the gizmo via the gizmo output SMA connector. I posted the correct link in the comment section of the online article. https://spectrum.ieee.org/geek-life...f-the-milky-way-with-this-diy-radio-telescope I hope that this will help those who want to work on this project.