UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Quiescent Current of a Yacht Boy 300 Radio

'LIVEWIRE?' · 17th May 2019, 9:15 am

Having just replaced a partially s/c transistor (T4) in one of the above, the radio now works fine, and, measuring the current when the set is powered from a stabilised PSU set to 7.5v, the minimum, with volume at zero is 20mA, and the maximum about 250mA with the o/p on speech peaking at around 1.4 watts into 4 ohms. Having mislaid my Yacht Boy 300 service sheets, I'm not sure if these are acceptable figures, so, can anyone tell me what the quiescent Current should be. The radio is only ever run from a 'wall-wart', but over the years the audio amplifier has failed twice. The last time I replaced all the transistors in the audio amp. with the types originally used, and, IIRC, one of the electrolytics, so I want to ensure, as far as possible that it's not likely to fail again.

17th May 2019, 9:15 am	#1
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Quiescent Current of a Yacht Boy 300 Radio Having just replaced a partially s/c transistor (T4) in one of the above, the radio now works fine, and, measuring the current when the set is powered from a stabilised PSU set to 7.5v, the minimum, with volume at zero is 20mA, and the maximum about 250mA with the o/p on speech peaking at around 1.4 watts into 4 ohms. Having mislaid my Yacht Boy 300 service sheets, I'm not sure if these are acceptable figures, so, can anyone tell me what the quiescent Current should be. The radio is only ever run from a 'wall-wart', but over the years the audio amplifier has failed twice. The last time I replaced all the transistors in the audio amp. with the types originally used, and, IIRC, one of the electrolytics, so I want to ensure, as far as possible that it's not likely to fail again.