This blend pot appears to be essentially a clickless no-load pot. I also see three lug, center detent blend pots. And then there are dual-gang, 6 luggers.
I like the description in the above diagram, being able to blend neck while on bridge, and vice versa, and all pups at once (guessing that's blend neck into position 4 (M+B), and blending bridge into position 2 (N+M)).
But I don't understand why that would work without either a center-detent type pot, or a dual-gang.
Can someone explain how this would work, and what the differences are in the various "blend" pots?
Mate! I know all about that, Ive just built it into my new Strat
It is indeed the simplest best way to get blended neck and bridge combos, or all three, in a Strat. Its better than the various dual gang designs because it is simpler and adds no tone-compromising extra resistances when not in use.
All it is is a pot that gradually connects together the hot wires from the neck and bridge pickups. Its best done with a 250k normal no-load pot, so at 10, there is no connection and as you roll down to 0, it becomes fully blended. The centre position 5 is not actually of critical interest, except as an in-betwen tone, so no detent there. You can make this no-load pot out of a standard 250k audio pot (ie a standard Strat tone pot) or buy a pre made no load pot.
When I first got my Strat, I wired it exactly as that diagram, and it worked fine. Then, after some testing, I decided that I wanted the blend action only in position 1 (B with some of N added), so that i can preset a tone there without also messing with the tone at position 5. This was also because I found that with full N, blending in B, there was less interest in the in-between tones than with full B blending in N.
From similar thinking, I decided I wanted the one tone control to only work in positions 2 to 5, so I can preset a muted tone but keep a full bridge tone. But those choices were personal to me and may not suit others (but im happy to share diagrams). These added features were done using the second half of the 5-way