Q. Should my " L" Rods be held a certain length from each other for finding metals?
A. In my 35 years of professional dowsing - and that of my late mentor, Verne L. Cameron - during his 44 years of professional experiences, no fixed lengths or distances separating L-rods is ever required; except that the rods are positioned directly forward; a comfortable distance apart; and reasonably level with the horizon.
Finding precious metals - or whatever? - depends upon phrasing the right question(s) posed in proper order while employing a reliable set of code responses developed well beforehand, so that the instruments' reactions operate beyond one's physical control via one's autonomic nervous system. Don't allow anyone's own notions and limitations to invade your own unique approach to dowsing. I can assure you that unnecessary dowsing fixations continue to be legion among locators the world over.
I'll vouch for the following rules maintained by old-timers, all of which seem to be unerringly true:
The object, or objective of one's quest must first exist... Avoid preconceived notions and out-of-control expectations. Finally, Always remain steadily focused while sustaining continuous (unbroken) contact with the specific goal of your search.
Good luck, Bill Cox