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Ground RTL-SDR to mast. Good or bad idea?

Posted: Tue Jul 17, 2018 2:56 pm
by Remon
I have a 2 meters aluminum mast tube on the attic with a Diamond X30 antenna mounted on top. On the attic is also my Raspberry Pi rtl_tcp server with a double shielded USB 3.0 extension cable to my RTL-SDR dongle. My idea was to mount the dongle with cable ties to the bottom of the mast so it can dissipate heat to the aluminum mast. In this scenario I only need 2 meters coax from the dongle to the antenna.

My question: can I do this or do I need to isolate it because it can cause ground loops or current leaks/static?

Re: Ground RTL-SDR to mast. Good or bad idea?

Posted: Mon Jul 23, 2018 9:35 am
by Remon
Other concern is that the ground from the dongle to the ground of the antenna is choosing the path of less resistance which can be the mast tube instead of the coax shielding. Could this affect the coax cable characteristics?

Re: Ground RTL-SDR to mast. Good or bad idea?

Posted: Tue Jul 24, 2018 10:39 am
by rtlsdrblog
I think you'd probably want to connect the coax shield to the mast at the top of the mast, and then if you like connect the RTL-SDR to the mast on the ground too. Make sure the mast is properly grounded.

Re: Ground RTL-SDR to mast. Good or bad idea?

Posted: Tue Jul 24, 2018 1:11 pm
by Remon
I do not necessarily want to ground everything. Nothing is properly grounded, it's just an 30 mm diameter aluminium pipe with an Diamond X30N antenna on top of it on the attic. I had this same setup around 10 years ago with a coax cable running to a lower floor.

The reason I want to use cable ties to mount the RTL-SDR to the pipe is only cosmetic. I can put a sheet of rubber in between it so it acts the same as the RTL-SDR is laying somewhere around the mast. My thought was: what if I leave the rubber sheet so the RTL-SDR can dissipate some of it's heat to the aluminium pipe?

I have had radio equipment in the past (scanners, receivers, cb radio's) that could be act strange when there was some strange grounding. I blew up (with a flash and loud bang) a packet radio TNC when the metal casing touched the metal casing of the 13.8V power supply. Since that moment I'm more careful..