Following the Peak and Dip instructions in the manual on my Valiant could be a bit un-nerving. Sometimes the plate current would Peg the meter for several seconds as I tuned the finals. Since that rig uses 3 6146's in the final and they aren't getting any cheaper I found a kinder gentler (and faster) tuning method using my O'scope.
Warning, if you try this, DON'T transmit into your scope! You will probably let all the smoke out of something expensive and neither you or your scope will be happy. Don't forget to reconnect the transmitter to the tuner/antenna! (yes I've done both, and was lucky each time...
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With the rig on, and warmed up, I connect the coax from the transmitter to one channel of the oscilloscope, then turn the oscillator switch on the rig to the Zero position. Peak the grid as you normally would and adjust for the recomended grid current (8mA by the book). You should see a trace on the scope, set up the scope to display the trace as a sine wave that covers a couple of divisions peak to peak, and wide enough to see a couple of wavelengths or so.
If you tweak the grid tuning, you will notice that the sine wave will grow and shrink as you pass through resonance. You will also notice that the grid current is changing too. You could tune the grid for maximum size on the scope and then adjust the grid current to the correct value if you wanted, but you would run the risk of running excess grid current when you peaked the wave form on the scope.
Next, adjust the final. The final adjustment will also peak the wave form on the scope, so tune the finals for the largest peak to peak value you can get. This will put your final tank in resonance, and without putting the HV on the tubes. Your done, set the oscillator switch back to the required position, and set the meter switch to read the plate current.
Disconnect the rig from the scope, connect it up to your antenna or tuner or whatever (XYL's cat?) You may need to tweak the final settings a bit, but I find that with my tuner preset to the correct settings for the band, I can key up the transmitter and its usually spot on.
I have found that sometimes even if the grid is tuned to "peak" there could be some distortion on the wave form. A slight adjustment to the grid tuning usually clears that up, and isn't very noticable on the grid current meter, your still tuned to the current peak. I don't know why that is, it may be something wrong with my rig or setup, but it makes me feel better that I can get a good sine wave out.
Well, Hope some find this helpfull.
