Re: #qsoparty Fun with 40m in QRO QSO Party, report #qsoparty


KEN G4APB
 

On Tue, Sep 15, 2020 at 06:41 AM, Hans Summers wrote:
Another question... in case anyone has any ideas... I have a 0-30V, 0-20A linear power supply type RXN-3020D. Purchased new last year. Same ubiquitous design thing, as made by many manufacturers. I power it on, and set it for 20V. Current draw on key-down is somewhere between 4.5A for around 50-60W RF output (including the current consumption of the QCX). *IF* I turned the knobs all the way clockwise the display reads 31.2V. HOWEVER... over the course of an hour of operating, the output voltage drifts downward. I have to keep making adjustments, turning the voltage knob clockwise a bit, to keep the output reading 20V. By the end of an hour's operating, the voltage knob is almost all the way clockwise and the thing can just barely make it past 20V. Any ideas anyone? I ought to open it up probably. But time is so short... 

Hi Hans, the user manual describes a ‘restricted current mode’, maybe you have inadvertently set it. Also, there is a warning that high levels of RF can affect it. Maybe you need to turn the psu off and on again at the mains to reset it and put some ferrite on the input and output leads???

 

73 Ken G4APB

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