UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - My first valve radio project

julie_m · 5th Jan 2017, 9:34 pm

I think the hum is being picked up on the (possibly unshielded) audio cable from the Bluetooth receiver to the PU sockets. This is upstream of the radio's volume control, so will be affected by that.

If so, it could be mitigated by careful routing of the audio cable away from the mains transformer, and / or by using shielded cable for this connection.

5th Jan 2017, 9:34 pm	#308
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: My first valve radio project - Philips 462A I think the hum is being picked up on the (possibly unshielded) audio cable from the Bluetooth receiver to the PU sockets. This is upstream of the radio's volume control, so will be affected by that. If so, it could be mitigated by careful routing of the audio cable away from the mains transformer, and / or by using shielded cable for this connection. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.