My new dummy load arrived yesterday allowing me to finally test the 80-to-630 meter transverter I built a few weeks ago. I had tested it briefly with a small under-rated load but lacked the ability to do so for a 2-minute WSPR transmission.
With the Ultimate 3S outputting 200 milliwatts on a frequency of 3675.7 kHz, the transverter mixed it with 3.2 MHz and provided a 15 watt output (17 watts DC in) on the 475.7 kHz frequency.
Operation was stable and I was my own first contact on this band, decoding the transmissions on my Flex. BTW, that's an efficiency of 88% and note that 15-watts output was produced with a miniscule input.
And now to send a QSL to myself...
I'm making progress on the 300 watt amplifier and will test it soon.