UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Nordmende Globetrotter 808 output stage problem.

Leon Crampin · 15th May 2022, 10:54 pm

I would alter the circuit, very slightly, to ensure that the Vbe multiplier turns hard on when the wiper lifts off the track, or its slipring tarnishes. In some cases, a highish value fixed resistor connected base to collector of the multiplier will achieve this without adversely affecting the adjustment range. Re-calculating the circuit and wiring the pot as a rheostat in the b-e leg of the network is not difficult and may give a better range of adjustment.

Leon.

15th May 2022, 10:54 pm	#9
Leon Crampin Octode Join Date: Nov 2005 Location: Surrey, UK. Posts: 1,870	Re: Nordmende Globetrotter 808 output stage problem. I would alter the circuit, very slightly, to ensure that the Vbe multiplier turns hard on when the wiper lifts off the track, or its slipring tarnishes. In some cases, a highish value fixed resistor connected base to collector of the multiplier will achieve this without adversely affecting the adjustment range. Re-calculating the circuit and wiring the pot as a rheostat in the b-e leg of the network is not difficult and may give a better range of adjustment. Leon.