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RE: GZ34: getting too much voltage drop

Posted by Tre' on February 11, 2017 at 16:07:00:
"My point is that at the input of the filter - be it choke input or cap input, the VAC RMS is equal to the RMS at the secondary minus whatever drop occurs at the rectifier."
No. A cap input filter will cause the voltage and charging currents to be higher at the cathode of the rectifier tube.
A critical inductance choke input will cause the voltage and charging currents to be lower at the cathode of the rectifier tube.
Cap vs. choke input filter changes the way the rectifier tube works.
The equation "VDC=0.9*Vrms(trans. sec.) for choke input" or "VCD=1.41*Vrms for cap input" is the input to the filter.
I just ran a sim 335-0-335 into a 5ar4 with a critical inductance input choke and depending on the DCR of the power transformer secondary and the total current draw, 290vdc at the cathode of the 5ar4 is about right.
Tre'