Doc Brown Power Supplies Checked For Possible HAM Usage

I’ve had several inquirys wondering if these power supplies can be used for Ham purposes. A local Ham checked one out and writes:

Dave …
I’ve used this with a Yaesu FT-817 (5 watt, around 2 amp), scanned across the bands, and found several places where there are “birdies” or RF that can interfere. It seems to be on the power line, since I had no antenna attached at the time.
1.805 MHz, 1.784, 1.685, etc. These likely come from the switching mode, since the signal disappears when the power supply is unplugged. I would suggest that HF ( from 1.8 MHz to around 30 MHz) may be usable on some bands, but not all. At VHF and UHF frequencies it is well filtered enough to use, that is at 140 MHz and 430 MHz. With its current level it could run a 100 watt repeater at VHF nicely.
Of course, this isn’t at the same level evaluation as someone at the ARRL or FCC labs, since I have not measured the actual level of signal involved. I can not see anything on the Tektronics oscilloscope, but it only goes to 2 mV/cm. A signal at that level would be rather loud.

John Hepner KA8ZSB

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