Surf Pi Pro running on 9V battery / metal stem

[sdesic]

Hello to all

I am trying to find results of testing Surf Pi / Pro detector with 9V battery but nothing came up.
I know it will work on 9V but don't know what results will it get with standard coil.

Also looking for test with all metal (al) stem and non metal one.
My old detector from 70s has all metal stem and only plastic part which contacts coil shell.
I might use tripod legs if it lowers sensitivity 5-10% ...
if it is more than that ... will use plastic or wood.

Any links ?
Thoughts?

Thank you.

[Waikiki_Sweep]

Hello to all

I am trying to find results of testing Surf Pi / Pro detector with 9V battery but nothing came up.
I know it will work on 9V but don't know what results will it get with standard coil.

Also looking for test with all metal (al) stem and non metal one.
My old detector from 70s has all metal stem and only plastic part which contacts coil shell.
I might use tripod legs if it lowers sensitivity 5-10% ...
if it is more than that ... will use plastic or wood.

Any links ?
Thoughts?

Thank you.

9V is bad because probably at 8.5V it will start malfunctioning because 78l05 voltage regulator and MOSFET trensistor required some minimal voltage. Also sensitivity will be a some lower because of lowering power to the TX impulses.

All metal stem may works if last one foot is made from plastic. If metal stem is near coil (no plastic) detector may be overloaded and does not work at all or works with very poor results.
Like forget about depth and about gold because decay of that "metal stem" target will be much longer than decay time of any gold target near coil.
Also any moves or vibrations of coil against that big metal piece like metal stem will trigger false target signals.

[sdesic]

9V is bad because probably at 8.5V it will start malfunctioning because 78l05 voltage regulator and MOSFET trensistor required some minimal voltage. Also sensitivity will be a some lower because of lowering power to the TX impulses.

All metal stem may works if last one foot is made from plastic. If metal stem is near coil (no plastic) detector may be overloaded and does not work at all or works with very poor results.
Like forget about depth and about gold because decay of that "metal stem" target will be much longer than decay time of any gold target near coil.
Also any moves or vibrations of coil against that big metal piece like metal stem will trigger false target signals.

I will try to make time to try this in person - not theoretic

[Waikiki_Sweep]

I will try to make time to try this in person - not theoretic

Sure you can.

From my "not theoretic experience" you have to hear "motorboating" sound once battery go as low as 8.5 volts or so.

Also probably you will need an oscilloscope so see that decay curve go crazy wide in close proximity of big piece of metal like your metal pole.
I have played with players, hummers, quarters, beer caps and watched it hundred times in real, not in my dreams too.

[sdesic]

Tested Surf Pi Pro with metal all stem...

Metal stem blocks detection... so I decided to shorten stem and to insert wood part.
When stem is metal + wood (10cm) it detects metal just fine.
Probably same depth as all plastic - or wood.

[sinclairuser]

if you have an old detector with an aluminium shaft, try the reverse remove the metal, replace the lower shaft with plastic, swap the bolt for nylon or plastic(if its metal), the best illustration of why its better with non metal parts is by modifying these old ones, if its anything like mine you may gain a couple of inches, i did.