Bandero umax II home brew

[mykaitch]

Hello all, well I'm back!
My home-made uMaxII works really well with an unknown coil from Ebay (runs at 13KHz).
BUT (always a but) if I put 40M across the AUTO all is fine. With no 40M it seems great in AUTO
(obviously) but it runs silent until a coin is detected - then it beeps etc. Now it seems to me that it is more
sensitive with the 40M, but then it runs with a background tone until it hits.
Disc mode is fine.
Any ideas ??? (I niow use same ICs as Tossoro)


Also, made small mod to my pinpointer which gave a BIG range increase. I replaced the diode with a transistor wired as a diode, this way its temp tracks with the ohter transistor. Even the LED gives and indication now by flickering and getting brighter with range.

[mykaitch]

I know this is stupid but I think I can reply to my own Q.
Without the 40M the unit is working as per the original - only I didn't realise that. Doh!
With the 40M across the AUTO switch what happens, in effect, is a very slow retune - which explains why RETUNE didn't seem to do a lot on mine, I think. Anyroadup (it's a Northern British thing, and I'm a Southerner so ye-hah!), it seems to work. However I really would appreciate any other comments (Yankee or Confederate is fine).
The stupid thing in the Tesoro manaul is where it explains Metal mode. "....move the coin towards the coil and try moving it side to side...." ...."this is called the no-motion mode....." Excuse me ?