Wee Goldquest mod for wee signals

[Kev]

Hi,
My hearing has accumulated some holes over the years, being assaulted in my youth with .303 rifle, shotgun and rock concerts etc., to name just a few. Anyway, my Goldquest had quite a low frequency threshold so I tried a slightly higher audio frequency which has proved more suitable for locating small or deep nuggets, and I would expect that it would also help locate those deeper rings and coins if you're a half deaf old fart like me.

Please don

 

[Kev]

Hi,
I did some detecting at the beach over the weekend and confirmed that the higher pitch audio is much better when it comes to hearing faint targets over the background noise.

My standard audio was 430Hz, with the mod, I had set it to what seemed a better tone for small gold nuggets, and this turned out to be 680Hz. I'm sure I dug targets deeper than ever before. The crash of the surf was not masking signals.

I think a slightly higher frequency than 680Hz would be even better if you were actually in the surf, although some waterproof phones use piezo elements which tend to inhibit lower frequency components of the audio anyway.

It would be interesting to know what the sound spectrum of crashing surf is, some days it really booms so I suspect there would be quite a bit of infrasonic sound produced.

HH Kev

 

[JCPinCt]

I don't know if it 's just me, but I see a 100k resistor and a 47k pot. Not the other way around as your description mentions.

 

[Kev]

Hi JCPinCt,
If you look closely at the resistor you will see 473 printed on it, which indicates 47 followed by 3 zeros, 47,000 or 47k Ohms.
The trimmer is 220k which is a little too high, but its what I managed to scavenge.
HH
Kev.

 

[JCPinCt]

Opps, my mistake, I looked at the resistor connected with the yellow wire and thought that was the one connected, I forgot about those newer flat type.

 

[Mark L]

Kev, do you think this type of modification could be put on a Whites PI Pro? Mark

 

[Kev]

Hi Mark,
I'm not familiar with the Whites units, but I expect that they are essentially the same, and would be easily modified, unless this is the unit that uses the microcontroller, I think one unit does?
In which case the chopping signal would likely be generated in software, and not easily adjusted, although it could be used to drive a clocking chip that could be strapped to provide higher and lower frequencies around the fundamental.

Hopefully Mr Bill will answer the qusetion for you...

HH
Kev.