Jeff, Thanks for the thought which is something I did not check. (nor do I know how at the moment, I'll have to find the book)
I did check the obvious solder connections that usually fail and even re-flowed them. The POT "seems" ok as when the amp finally does reach full power, the POT varies the output power just fine. Again, this amp is extremely clean and quite healthy once it finally reaches full power. Back to the bench tonight....Thanks!! Adam N2ACF Jeff DePolo wrote: >> After letting it cool, I key'd it up again. It immediately went up to >> only 20 watts, then after about 30 seconds it hit 75 watts >> and finally >> after close to a minute and a half, it hit 100 watts. I let it cool >> again, and same thing. This appears to be the way this amp is as >> nothing I can do can get it to change. I checked the exciter and >> immediately upon being key'd it puts out 220 mw. >> >> Any thoughts or suggestions would be greatly appreciated. >> > > I'll give you the same recommendation as I would give anyone with a > varying-power problem on an amp with power control circuitry - meter the > controlled stage voltage! If it's constant, then you have an RF problem > (bad connections between boards, a failing component, etc.). If it's > varying in correlation to the change in power output, then the control > circuitry is causing it (possible causes include the power control pot, > thermistor, power control hybrid, pass transistor, etc.). Divide and > conquer is your best technique, and this is an important first step. > > --- Jeff WN3A > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > > >
