Good Evening, I have a Micor 75 station power supply that is acting up. When the repeater is idle, the voltage output appears clean. But as the load is increased (ie: power output increased), the voltage sags and I get an annoying hum on the tx (indicative of AC ripple on the dc side?). It started out as a barely noticeable hum; the past few days it has gotten to the point where I just shut down the repeater's tx.
I haven't had a chance to get to the site to swap it out with a spare. But I'm curious as to what kind of repair I'm in for, and others' experience with Micor supplies. What tends to be the failure and/or cause of the above condition? Pass transistor failure? Filter caps? Ferro-resonant circuit (cap)? Thanks for any input Eric KE2D
