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the only thing missing is optimal settings for the delay and test points for to setup with a scope so has anyone got pictures to share and what point they have taken the readings ?
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Don't think there is such a thing as "optimal delay"
Different targets are better at different delays.
I got a selection of finds silver ring, gold ring, fibula and so on and found the best average. If I was just detecting the beach I would change the setting more for gold and less for the copper alloys. As at the moment a ladies gold ring is a couple of inches below its maximum -
What do you mean by change settings? My baracuda is detecting a small gold ring at maximum 8inch, faint signal, with minimum delay possible. I use basket coil 11".Originally posted by Koala View PostComment
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Originally posted by ionut_mtb View Post
http://www.geotech1.com/forums/attac...0&d=1459631333
By adjusting the delay Can get nearly 14" on the gold ring but then the fibula is down to 3"
Coil is just solid enamelled copper. Post specs on here but can't seem to find the postComment
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Adding a pot so you can adjust the Pulse Rate can change things too.Comment
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so whats the best points to take the readings of to set the delay using a duel scopeComment
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http://www.geotech1.com/forums/forum...Published-2015
good starting book to begin a way into electronics. ITMD. believe me now.Comment
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Here if you want absolute Delay Measures including Propagation delay. Chn 1 end of Tx is the start in time. Chn 2 first and second sample time.Comment
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Nope just by main sample delay within the range of adjustment.
Timings are in the build document.
http://www.geotech1.com/forums/showt...roject-DetailsComment
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the timings is there but no details i already looked at that @homefire that's the points i was testing but i used the opamps output, all i was looking for on this thread was a quick setup for people who own scopes and some details and info lol, mines is already setup and working fine i just think this info is missingComment
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optimal you meant the depth or what? what you want? bara works with fixed PULSE WIDTH 50 us, no possibility to grow the depth.
DELTA PULSE works with variable PULSE WIDTH from 150 to 500us. DELTA PULSE has optimal PULSE WIDTH if
you meant pulse width.Comment
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You wanted Optimal. Optimal for Me in a PI is short as possible sample delay. I seek Low Conductive targets like Gold. You may want Longer Delays to be Optimal for what your looking for. The Three point I referenced are the point you would need to measure to include All Delay after Tx Shut OffComment
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this is the way i set it on pin 6 u4 i set the pot to 0 and adjusted the trimmer to the point before it flat tops this seems to be the best setting for the delay
and when it set you turn the pot to max resistance you get
i would say that's optimal for my coil im using, or am i setting the delay wrong or is there a better way ?Comment
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Sounds like you doing it right to me. The Rising Edges are your time marks. Using the Test Point I described measures Absolute Delay including Propagation times of the Fet's.
I used the Old Schematic showing points for Chn 2 at 4066. On New schematic it would be just after the Fet's.
STEP 6
Sample Pulse Generator (see Fig.
:
Fit R14 (20k cermet), R15 (15k), R17 (150k), R21 (12k), C7, C12, C13, C14 (4n7), PL2 (10k
Sample Delay Pot).
Monitor the TX oscillator using an oscilloscope at U4 (pin 4) using channel 1, and main sample
delay U4 (pin6) using channel 2. Trigger off channel 1. Short pin2 of PL2 to either pin 1 or pin 3 (or
use 10k sample delay pot adjusted to minimum resistance setting) and adjust R14 for a minimum
sample delay of 20us. The final minimum sample delay will depend on the coil you've constructed,
but 20us will be ok for initial setting up. If no oscilloscope is available, then build the sampling
integrator in Step 7 before adjusting R14.Comment
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