[Amps] arrrrgggg!!

[Carey Lockhart, KC5GTT]

ok guys i have the amp back together in the yu1aw lazy builder. now i am getting much lower efficent 

plate 3400 full load
current 1.2a
drive 100w
output according to my cheap meter 1600 and my other cheap meter 1900

eff. around 35%

now i am wondering how to determin actual output from these values. is there a way? also is the flapper capacitor a bad way to go? 

Carey