UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - How effective is an earth for reducing noise on AM?

G6Tanuki · 25th Nov 2020, 6:16 pm

In my case, like I said, I took the choke from a scrap computer-PSU and fitted it inside an [earthed] diecast box.

My 840A has a 2-core mains lead (it's an AC/DC 'live chassis' radio) so I just ran a 2-core cable from the output of the filter to the radio's input.

(The 840A has an earth-terminal on the back which connects to the inner circuitry through a high-voltage ceramic capacitor to allow the passage of RF to earth but blocking any significant supply-frequency currents from getting out)

25th Nov 2020, 6:16 pm	#28
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,996	Re: How effective is an earth for reducing noise on AM? In my case, like I said, I took the choke from a scrap computer-PSU and fitted it inside an [earthed] diecast box. My 840A has a 2-core mains lead (it's an AC/DC 'live chassis' radio) so I just ran a 2-core cable from the output of the filter to the radio's input. (The 840A has an earth-terminal on the back which connects to the inner circuitry through a high-voltage ceramic capacitor to allow the passage of RF to earth but blocking any significant supply-frequency currents from getting out)