I made a simple linear power supply for my transceiver using 12V 30A transformer, four diodes RHRP3060 forming a rectifier and three 30_000 µF capacitors connected in parallel. I also used a 200 Ω 50W resistor to discharge capacitors in a few seconds after powering the device off.
The power supply works reasonably well and I already made a few QSOs using it. However if I transmit in FM using 100W the oscilloscope shows +/- 6 V ripple. It's not that bad in SSB though. In this mode I see 9-15V which is in safe range for my FT-891, which is 13.8 +/- 15%.
What upsets me is that the cheapest switching 12V 29A LED driver I could find gives only +/- 1.3V ripple in FM mode. If anyone is interested, it's GDLI-350-IP20-12, the price is ~15$.
How can I reduce the ripple of my power supply to approximately the same level? Should I use even more capacitance, a high-pass filter, or maybe something else?