UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Output transformer simulation using resistors etc.

kalee20 · 29th Sep 2022, 10:03 am

You could use a choke, paralleled by a resistor of the load impedance you want to load the valve with.

Or - better still as an accurate simulation - just use a beefy resistor. Down side is you'll need to use a far higher HT voltage, to compensate for the DC voltage drop in a pure resistor. So if you're testing a 6L6 with 300V on the anode, 70mA anode current, and 3.6kΩ load impedance, you'll need a 552V test supply so that the quiescent anode voltage is the 300V that you want. But the valve won't know any different from the choke/resistor, or the actual circuit with a (good) OPT..

29th Sep 2022, 10:03 am	#2
kalee20 Dekatron Join Date: Feb 2007 Location: Lynton, N. Devon, UK. Posts: 7,087	Re: Output transformer simulation using resistors etc. You could use a choke, paralleled by a resistor of the load impedance you want to load the valve with. Or - better still as an accurate simulation - just use a beefy resistor. Down side is you'll need to use a far higher HT voltage, to compensate for the DC voltage drop in a pure resistor. So if you're testing a 6L6 with 300V on the anode, 70mA anode current, and 3.6kΩ load impedance, you'll need a 552V test supply so that the quiescent anode voltage is the 300V that you want. But the valve won't know any different from the choke/resistor, or the actual circuit with a (good) OPT..