I started with the 66TR too in the mid '70s
Dan, the addage that if someone wants more gold rings, to "lower your disc and dig aluminum junk" is only a small part of the recipe for "finding gold rings". Because Dan, it's already a "given" that gold and aluminum share the same conductivity ranges. Thus pity the poor person who goes on this advice alone, lowers his disc, goes out to a junky blighted park, and digs aluminum till his arms fall off. Oh sure, he'll "eventually" find a gold ring. But this is folly for a lot of junky blighted parks, where the ratio can be 500+ to 1 for the aluminum to gold ratio. Thus the BIGGER part of the advice of "how to up your gold ring count" is NOT simply "lower your disc, and dig junk till your arms fall off". RATHER, the bigger recipe is: WHERE YOU HUNT. There are places where gold ring ratios are higher. Namely swimming beaches. And even within various types of turf, some are going to be better than others: If a person is hunting at turf zones where historically picnicking has gone on (eating, drinking, and with BBQ pits there), that is a certain recipe for junk and poor ring ratios. Because if this is where people sat while eating and drinking (next to picnic tables and BBQ pits), then go figure: they have their sodas, aluminum wrap for their food, etc... And the BBQ pits are prone to have molten nuggets around them (d/t people thowing their cans in the fire, or heating aluminum foil wrapped items, etc...). Contrast to OTHER forms of turf, like soccer and athletics (where it's more athletic frolicking, rather than eating and drinking), then your ring ratio is going to go up, vs the aluminum.
So ........ maybe you want to go put a post-script there on your podcast, that since the ultimate goal of such advice is to up one's gold ring count, then the advice to "lower the disc" is only one part of the recipe. The bigger part of the recipe is WHERE you hunt.
I had the unique opportunity, in 2006, to hunt in "relic mindset" (ie.: dig everything conductive) in a junky blighted park that was being torn up for installation of astroturf. So we "dug all", since the place was torn up, and thus, no fear of holes, etc.... And we got hundreds of silver coins, scores of Vs, buffalos, etc... and yes, some gold rings. But I can tell you for a fact, that the ratio of aluminum to gold (d/t I saved all my dug targets over a 2-week period for a careful study) was easily 500+ to 1. Simply would not have been worth it for anyone to "be a hero" and try to farm this junky blighted ghetto park thinking he was going to angle for gold rings, if it had not been for the tractor work going on.
