TGSL 29.2 KHz

[Rumcajs]

Ok, guys,

it is one, when you changing the search frequency. Your oscillator maybe fine working, and after long-long time you retuning correctly the receiver coil.
It is good, but what is it the R-C filters, and (for examle) what is the parts of about opamps? Anybody recalculate its according to new freq?

I think, if you not changing these parts correctly, the result is worse, no better.

good hunting

rumcajs

[simonbaker]

Howdy,
"Nothing new under the sun" "Seek and you shall find"
Thanks to the generous contributors on this forum the answers are already here.
http://www.geotech1.com/forums/showt...ghlight=diablo

Seems that sensitivity to small targets such as nuggets is not just a function of frequency, but also ratios of inductance between Tx and Rx coils, this is one reason why the Lobo and Diablo etc., have such large Rx coil inductance in relation to the Tx, it is a transformer boosting effect magnifying sensitivities.

Cheers
Kev.

I hope you try experimenting with higher frequencies and tell us what you find. However, in my experience it is very difficult to deviate from the reference design and get a good working MD, I don't know why, but be prepared for lots of tinkering and don't give up.

The TGSL has the RX circuit tuned to about 1.11 X the TX frequency. You may want to keep that ratio to start with.

Keep us informed, even failures are interesting.

Regards,

-SB

[Kev]

Hi Simon,
Yes it does seem more trouble than it's probably worth, and I'm tending to agree with homefire's decision, but I think I'll try the Diablo first. It doesn't have disc, but hey we're meant to dig everything on the goldfield anyway, and this has been borne out a few times in my case when targets identified as iron by the disc turned out to be nuggets with decomposed reef material attached that was basically iron ore, tricking the circuitry.

Once I've played with the Diablo I may revisit this, but I feel it would still need a much higher inductance Rx coil and we know the TGSL doesn't like too much of a difference in this area, but with the great info Carl provided in the above link about tuning the input filters I think it would be possible. All the same though it would be reinventing the wheel, and as we start to get older time seems to evaporate much quicker so economy of time may dictate otherwise.

Cheers
Kev.