Hello,
The TDI sl has not just a steadier threshold than the DF or pro but it's a much deeper machine than the DF.
I did waterproof mine and here are some thoughts about it:
-The machine in some conditions is scary deep; when environment permits (no waves, no crowds,cloudy weather) and I can push the pulse and sensitivity dials, sometimes the targets are too deep for my scoop to be recovered. A really big and good scoop is needed with a TDI sl.
-if you have long periodic waves, the threshold will follow the water column in such a way that the TDI is almost unusable unless you turn the pulse dial waaaay down. This is also true for the DF. The problem is they both lack a SAT dial to adjust threshold speed in relation to wave frequency so expect a sensitivity reduction in rough sea.
- the SL injects more current in the coil than the DF, that means lower battery endurance. I have a custom battery pack but at present I can't go past the 3 HR and 45 min. of endurance. I'm planning to double that but it will be a challenge I see.
-the DF coil is too sensitive to tiny bits of rust , a mono coil is suggested for the TDI for detecting in the surf.
-I'm consistently recovering small chains and small earrings with the TDI
-with every pulse detector you have to bring a big trash bin with you!
-do I find gold? A lot, but it'not just the machine, it's also how and where you search for it.
About your specific question, the SL threshold is a "synthetic" one , it's almost artificially steady, so there is no doubt that you'll lose the faintest signals on the SL but on the other side you have a much more sensitive machine than the DF, so , who wins?
To really have an edge against the DF you need to mod the SL electronics with some of (saint!) REGs suggestions. Ask him information about it.
Cheers
Lucar
