A guy found this detector in a wood pile at a local factory. Looked like it had been there for years, weathered badly, shaft was broken and coil was busted. As a challenge they gave it to me. Two days later I installed batteries and low and behold it came on. Couldn't find a manual so I went into experimental mode and can say I was impressed with the air test (for a China product).
To start with I thought it was a single tone machine, dime and nickel gave a high tone, but adjusting the ground balance and the discrimination revealed attributes that reminded me of the TDI. Now a nickel gives a low tone and a dime remained a high tone.
Next I took the machine to my test garden of over 10 years and was shocked to hear a repeatable response of my deepest targets.
Please note, I’m not promoting China products, only indicating what I found.
There is one adjustment on the side that I’m wondering about not sure what it might be.
Would also like information about this machine, the internet really doesn’t indicate when they were manufactured or much detail.