MINE_LAB -F1A4 -A/OK- IMOP..

[detectormods]

I am investigating the development of changing the control range of of the GB tracking speeds.

If you you want to discuss use the email address on my website, I do not hang out on the web forums, it maybe weeks before i revisit.

[downhalo]

Interesting... had a question about that Woody. If you were to leave the detector (tracking) constantly would it effect performance in a negative way?

[detectormods]

It depends on tracking speed, too fast and kiss targets goodbye unless they blow your ears off, too slow and it will be out of balance , then you get ground noise and hot rocks , possibly obscurring nuggets.

[downhalo]

Yeah, I guess if it were meant to function that way it would be in the list of features.. Honestly I should have just shipped off a detector for mods, but I'd rather learn by doing..

[downhalo]

Well maybe one-day someone will post up some info on threshold... frequency... Worked out the gain, does a decent job..

[petere]

Hi Downhalo
Would it be possible for you you to post some info on the gain modification?

[downhalo]

No. last time i post mod info, the so called 'developer' of said mod sent me a rather ***** tastic email threat..

[petere]

OK, Thanks for the reply. Will keep searching

[downhalo]

The one you want is the one Woody mentioned above. involving 2 resistors.. its a little more effective..

the gain i fiddle with is a single 3.3k resistor replaced with a 5k pot, limited to 1.5k-4k min/max..

[downhalo]

To clarify the 'developer' quoted was sarcasm, the person who emailed me probably had nothing to do with the development of the mods..

[JamesAU]

How did you all go with these mods? I gave up on my F1A4 a couple years ago, and bought a GPX 4500. still be interesting to hear how they're working 6 years on (if at all)

[Kev]

Hi James,
I stopped posting on this after a request from some persons who had invested a lot of time and expertise and no doubt money getting their F1A4 units modded and onto the market.
I lost interest when I got a GPZ, but my F1A4 running the UXO timing on a large mono would be the deepest seeking handheld gold machine, deeper than a 2000 and with less instability.
I removed the oscillator inductor and injected a digitally controlled clock source that enabled me to speed up or slow down the timing train, so on the UXO timing I could build some hefty currents up.
As well as the four F1A4 timings I could select one of four 2100 ones, along with a couple I modified myself, but as I said the GPZ put an end to development.

I decided to go along with the request not just because I respected the people, but because I believe I alienated myself from a number of people I really admire such as Eric Foster and Reg Sniff, because I let loose some of their trade secrets, at least I documented them for all to see on here, not that they couldn't have discovered them for themselves, but to hand these things to people on a plate was my undoing.

Presently I'm experimenting with an idea of Eric's (unfortunately the crux of it is patented) and it is proving to be a super method. I suspect some of this is what got Minelabs' nickers all twisted with Whites.
Eric must have a better mental picture of how the ground is excited by magnetic fields than anyone else on this planet. But I must stop here.

Cheers
Kev.