Thanks all, it was a great day and I'm still reflecting...no matter how good it gets I always want more
Mineralization is not bad here; I usually keep GB at 80 with infrequent adjustments. I could probably keep it at 90 all the time with no problems. Anyway, last year I started using 12K as my main frequency so I could hear a wide range of conductors; I use an almost identical 4K program in an adjacent slot to check targets (of course this really doesn't help with deeper low conductors). The freq, TX and a slight notch adjustment are the only differences. In the 12K program I've kept TX at 1 because I don't need the extra depth it may give me in my area and 2) I hunt very little clean ground which doesn't give me the option of sending maximum power into the ground without negative consequences. TX-1 gives me the clarity of ground and target response vs TX-2 or 3. The way I think of it is (and I read this somewhere) that if I increase power into the ground beneath the coil through increased TX settings, this allows me to reach those feint targets at depth limits, but it also increases responses from the ground which promotes signal instability (think how 4K, with it's un-adjustable TX-3 setting can cause erratic behavior in some areas). So if I had difficulty getting needed depth with optimal reactivity, silencer and sens settings and with an 11-inch coil, I might consider bumping up TX a little. But in my area I keep TX at 1--I would adjust sens higher rather than emitting more power into the ground with TX adjustment. Sens simply adds amplification of those imperceptible blips at depth limits so they can now be heard and identified in the audio circuitry--still, you can have too much of a good thing with sens too. Yesterday, the Deus' response to the Barber half (4-5 inches) was clean and discernible in my 12K program--in fact my settings were too much for that target, but I was digging targets at a range of depths up to about 7 inches, so I needed those settings despite being aggressive for a 4-5 inch half dollar. And although the half was easily identifiable with my 4K program, it pushed the limits of power and consequently didn't sound as clean and came very close to sounding like an audio overload (my setting is at 1). While I couldn't change TX in 4K, I did take a look at the xy screen in both freqs and the straight line was sharper and cleaner with 12K than with 4K, which I attribute to the signal stability produced by TX-1.
Keep in mind this is the philosophy I use in my area where targets primarily range from 0-7 inches. Do I risk missing smaller targets at greater depths with this setup? Probably, but I can check iffy high conductor signals with 4K or go from reactivity 2 to 1 or even 0.
This was the long way of telling you why I use TX-1, but here it is