The power supply you listed above that is rated at 75 amp goes on ebay for 169$. The reason they are so cheap is they are rich in RF hash/noise. The ebay site lists the frequencies the birdies are on. I believe it was 80 and 20 meters but cant remember. The amps look to be of decent quality, just no rf filtering. But for use on 11 meter, they will do just fine.