I have plans to start listening on S-band and L-band satellites and need your help please! This is a new area for me and not sure what to get. Type of LNAs and antennas to use? MMDS downconverters, NooElec HamItDown or something else?
Also, in the future it would be fun to connect it to SatNOGS, but as SatNOGS does not handle SDR with downconverters, what type of SDR to use?
regards
/Lars SM0TGU
Hi,
I have some build pics on my recent L- and S-band here.
They are all helicals with preamp directly at the antenna feedpoint, just at the back of the reflector.
I am using PGA-103+ for most of the builds, there’s a bunch of boards and kits out there.
For the SDR I recommend using one that can handle the frequencies directly and no converters. If this is impossilble, there can be changes made to the flowgraphs so it supports this, althou it is a decent amount of work and lots of small changes needs to be made to fully support it from the config and runtime. Or just make it hard coded in the flowgraphs (:
adalm-pluto, hackrf, usrp, probably a few more.
Thank you @SA2KNG Daniel for information about your setup. Very nice pictures (I remember I have seen these before 
) I think this is a way for me to start with some simple Helix and LNAs.
I have a question about 12V to 5V conversion, have you done that converter yourself and it is RF quiet?
Also I see that you are using some Bias-T that are in enclosure, where have you purchased these?
The regulation is done with common linear regulators, some lna have built in 12-5V and some don’t, all depends on how I want to feed them. 12v I usually filter out from a good quality smps, 5V with 7805 or similar.
The bias-tee I use in the box is RF DC Block DC Block Stable Structure Aluminum Alloy RF DC Block Bias T-piece | eBay, but I have used everything from home made to high power commercial stuff. For receiving I like the smaller ones.
One of the setups has a regular transformer and linear regulator, but in my testing it hasn’t made much of a difference compared to filtered smps.
If you want to start real easy, to try things out, you could try the RTL-SDR Blog Active L-Band Patch antenna set. It is a plug and play antenna with built in LNA for 1500 - 1700 MHz. You can buy it from the interwebs for about EUR75. You can use a nooelec smartee with built in always on bias-T as SDR. It works with SatNOGS.
It is pretty small, so you can attach it to a window of even put it inside and try various places for best reception.
to try things out, you could try the RTL-SDR Blog Active L-Band Patch
I would actually wait for the new Discovery Dish. It will maybe be double the price but then you have a real dish with feed and you can use the dish with other feeders.
https://www.rtl-sdr.com/the-latest-progress-on-discovery-dish/
The L/S-band helix is made out of solid center conductor from a RG213 or similar.
I also have the L-band patch thingy, sure works and probably good in a very noisy env, not super strong thou.
I think I have some plans now for an upcoming S-band SatNOGS station. I will first try a HackRF One, Helix omni antenna (think I start with S-band) with LNA, and see what I can receive.
2nd station will be placed at the rotor and probably be downconverted signal with NooElec Ham It Down. This will be used for manual receive. This will have to wait until the snow and ice is gone
Thanks to @SA2KNG - your pictures of your setup has been of much help.
Make sure you have a good filter when trying S-band, my experience is that without a filter 2.4 GHz wifi is making reception difficult.
Good catch @PE0SAT I think that will be the 2nd step for me. I need to just get started first, start some manually RX and see what the RF spectrum is like here.
Hello,
For S-band RX I use a KU LNC 2027 downconverter from DB6NT with a 40-turn helix antenna. The downconverter includes an LNA and is powered by the coax via a bias-T.
73, Nico