Let's say I have 2 grenade style boxes and x number of WWII crystals all the same frequency. All work perfectly in box #1 with close to 10 watts from the IRF510. In box #2, half are associated with power close to 10 watts, half get anywhere from a couple needlewidths of power to about 1 watt. Any suggestions of what components to mess with? About all I can guess to start is mess with the nice mica caps right before the antenna output and see if jacking around the values +/- 50-100 pF fixes things for the bad crystals yet makes the good crystal output suffer a bit. I already optimized those when I built the boxes. Theoretically speaking.