I just purchased a new 6' 1090MHz 9dBi antenna from NooElec. It has an N-connector at the antenna to SMA connector of a 30' RG58 cable. I will be installing an LNA at the antenna in the coming week. I have conflicting info on how to ground this antenna. It is on my roof. The house ground is closest, but the 30' cable connects to my NooElect NESDR on the opposite side of the house from the house ground. What's the best option here? Connecting a grounding wire at the antenna and then to the house ground? That would be closest. Would the cable still be safe from a lightning strike? Would the ground wire carry the charge to the house ground and bypass the cable connecting to the SDR? Also, would the ground wire need to be at the in or the out end of the LNR? I'm about as new as they come to all of this, so I am grateful for any assistance.
RG58 is high loss. You need to use LMR-400 or LMR-240. https://www.amazon.com/gp/product/B013CY0IRU Use arrestor to run wire to ground. https://www.amazon.com/gp/product/B078NT5M37/
Loss on that distance with RG58 is going to be at least 5dB after connectors. Add in the arrestor, interference, etc etc. Just use good cable.
Most LNAs are 20 dB or more amplification. 10 dB cable loss is not an issue after that. The LNA must of course be at the antenna. Have you tried such a configuration and had a bad experience with it? I don't have practical experience with such a setup, but i've read about quite a few setups that had 20m of cable (probably rather good quality) and a splitter behind the LNA, and the reception was not affected.
Just helped a guy get one setup that used a cheap coax off your github list - could only get 5NM ... I need to go through and make some edits to your git. The biggest issue I've seen setting up 100+ of these are poor quality coax, not only does it have huge dB loss but some of them also pick up local EM interference. Very rare there is a bad SDR. Poor power supply are more common. Bought good coax, setup now gets 200NM.
I've changed the list recently and stopped linking the CFD200. Personally used the CFD200 and it worked just fine, but if you get 20 m of it, it's obviously a bad choice if you don't use an LNA in front of it. Also curious which exact product that particular user got, maybe you have a link.
For europen feeders: https://www.dipolnet.com/coaxial_cable_50_ohm_tri-lan_240_1m__E1171_1.htm https://www.dipolnet.com/coaxial_cable_50_ohm_tri-lan_400_wll_1m__E1173_1.htm https://www.dipolnet.com/n-plug_to_sma-plug_cable_rf-5_10m__E83293.htm They have all accessories, choose your country (top left).
I'm pretty sure James is talking about me... I used the RTL-SDR and corresponding LNA, two sections of coax, one lmr400 at 30ft and one cfd200 at 15ft - both were listed somewhere in the forum. The LNA was bad, so that was part of the problem. The connection between two sections was poorly conceived and that was a problem - I had started with the 30ft LMR but it wasn't long enough and I'd bought female to female so I needed to adapt it anyway and decided to do so with an extension. But as James said, once I replaced the coax (and removed the bad LNA) I went from 5NM to almost 150NM. Once I got a new dongle and an LNA that worked I went to 200NM. So I had a few issues but clearly cheap coax (and a mickey mouse set up with two sections joined together) was the biggest issue.
Reading about quite a few bad rtl-sdr LNA lately, a shame really. Even if they seem to replace them willingly, it's not good. Maybe you got a RP-SMA adapter to bridge the two cables? If they are properly connected, i wouldn't see a problem if the cables are genuine. With a bad LNA, you'll get really bad reception or even no reception.
A separate heavy copper ground wire should run from the mast to the closest ground point. Re: lightning strike... nothing will protect you from that. That’s not how antenna grounding works. A ground wire bleeds off static charge buildup to prevent lightning in the first place.
