UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Thorn 6204 hum after fitting new plug wire

Lucien Nunes · 20th May 2021, 9:24 pm

Good. So it sounds like the low level was caused by poor contact in the record/play switch, and the ineffective volume control was due to the anticlockwise end of its track not being grounded via the coax.

Now, once you are sure it is entirely back to where it was when you started, consider changing at least a few capacitors even though it is working. The output valve grid coupling cap can damage the valve and transformer if it fails, and if it is one of those Hunts Moldseals I can see in the pic, it will fail in due course. Someone with a circuit diagram will be able to see which, if any, others are immediate cause for concern.

20th May 2021, 9:24 pm	#39
Lucien Nunes Rest in Peace Join Date: Apr 2008 Location: London, UK. Posts: 2,508	Re: Thorn 6204 hum after fitting new plug wire Good. So it sounds like the low level was caused by poor contact in the record/play switch, and the ineffective volume control was due to the anticlockwise end of its track not being grounded via the coax. Now, once you are sure it is entirely back to where it was when you started, consider changing at least a few capacitors even though it is working. The output valve grid coupling cap can damage the valve and transformer if it fails, and if it is one of those Hunts Moldseals I can see in the pic, it will fail in due course. Someone with a circuit diagram will be able to see which, if any, others are immediate cause for concern.