2m & 70cm Lindenblads, and multiple SDR hookup


#1

Greetings,

Just thought I’d share some work I’ve been doing on a non-rotator station. Thanks to cshields we started by building a couple 70cm paralindy type antennas discussed around here, light testing has shown those to work ok. I went onwards and built a proper 2m Lindenblad as well based on the AMSat article and some thingiverse parts I found:


Finally this weekend I was able to get things assembled into a testable config:
Antennas
Enclosure & guts

I was also able to feed two separate SDR’s off this pair of antennas. I know others have done some clever things with feeding multiple satnogs clients off a single SDR. I’m not that clever yet, just figured I’d try out splitting the LNA output to multiple SDRs. I’ve been hunting down wide-band power dividers on Ebay to use for the antenna feed combiners as well as splitting the post-LNA signal to multiple SDRs. I’m using this LNA which others have had success with.

I was able to get a successful decode of Bugsat-1 on this setup indoors with a single client hooked up as it passed within view of the windows.

Next I hooked up the second client and SDR. It seems to have been successful, although the pass was not in a good enough orientation of the windows to get a decode this time (scheduled an observation on both stations):
Station 1: [https://network.satnogs.org/observations/437603/]
Station 2: [https://network.satnogs.org/observations/437604/]

While not a great observation, it at least proved I could get the signal on both SDRs. I intend to hook up a third RPi/SDR in this enclosure by the time I get this ready to deploy outdoors. Hopefully after this super cold weather passes I can get it outdoors for more testing.

I’m open to suggestions on this setup, just wanted to share what I’ve done so far.

Thanks.


#2

My UHF station is also running a “paralindy”, and I’ve come to the same conclusion… it’s “ok”. Mine is attic mounted, but even then I’ve seen better performance from simple verticals mounted right next to it. The circular polarization is noticable - but gain is poor. I had plans to move it outdoors, but I’m in the process of building an az/el station so those plans aren’t really firm anymore…

–Roy
K3RLD