first thing i would check would be aging solder joints, all the expansion and contraction due to heat and cold can make them loose integrity.
--- On Mon, 11/23/09, Adam Feuer <[email protected]> wrote: From: Adam Feuer <[email protected]> Subject: [Repeater-Builder] UHF Mastr II PA - SLOW To: [email protected] Date: Monday, November 23, 2009, 6:27 PM Hello All, I have on the bench into a dummy load an exceptionally clean Mastr II 100 watt UHF PA. It appears to be a "late model" version because it has the Z-Match board right above the RF output connector. At 13.6 volts and 21 amps, it's doing 100 watts easily. I can vary it down all the way and vary it up to about 128 watts. So, to me it seems like it's in good shape. I left it key'd for 30 minutes and the current and power output stayed the same, 21 amps and 100 watts. 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. Thanks!! Adam N2ACF
