Pulse Star II (first analog version)

[ivconic]

Anybody use magnetic reed switch for reset button?
Almoust contactless, provide 2 cm distance. No dust and mud on front panel.

Works 30-60 meters underwater too (by MikiPn):

[ionut_mtb]

From this perspective now, knowing what i learned in meantime; for me is better to have one, two.. maybe few fixed and accurately known delay presets; than to have potentiometer like on Delta Pulse and always turning it randomly.
PSII is having 4 delay presets, fixed. And i am using "1" most of the time.
Only with coil 2x2m is beneficial to switch it to "4" when search for indeed large objects.
I almost never used "2" and "3", except in case of a very "hot" soil. Rare case.
So, the same could be done at Delta Pulse. Instead potentiometer to put just few fixed values.
With same coil only one fixed value is enough. Maybe two. For normal and "hot" soils.
Those are "slow" coils and detectors and without GEB feature, not nugget hunters. Therefore no need for wider delay adjusting range.
PSII is really sensitive and "deep" at "1" and very slow and "deaf" at "4".
Therefore at "1" it can react to soil sometimes. Sometimes is enough just to lift coil few inches from soil.
I don't search for small and medium sized objects with it. I have Deus for that part of a job.
PSII with 60x40cm coil (at present i made that one) can reach deeper than Deus for larger objects.
So all ends up in combining the detectors in different kind of searching.
For that purpose Delta Pulse is good the same.

What delay preset and pulse width you use (uS value) to match coil size/target size? What preset values should i use for delta pulse when using >60cm coils. Example 60cm, 1meter, 2meter coils. Thanks

[ivconic]

What delay preset and pulse width you use (uS value) to match coil size/target size? What preset values should i use for delta pulse when using >60cm coils. Example 60cm, 1meter, 2meter coils. Thanks

Ask Eric. He will enjoy to answer you.

[ivconic]

Joking of course!


You got me unprepared with that question... i must admit.
It is shameful to had PS2 Pro almost 20 years ago, today to make several PS2 copies... and yet not knowing the timing schedule of it!!!
Wow!
Shame on my account!
So... this is product of battle between my ego and my indolence...
You do the rest of math on this.

[ivconic]

P.S.
You must understand that i am firstly in my mind the detectorist and just secondary the electronician.
I don't think in "microseconds" when on site, searching for the target.
...
The rest of the theory is already "re-washed" and "re-chewed" so many times on Geotech.
Larger the coil, longer the delay; more deeper and more larger targets... and so on.
Obviously, from the timings schedule posted in previous post; only sampling delay set at position "1" will be suitable for smaller targets, preferably smaller diameter coils used.
As explained with simple language (my most favorite) in the PS2 and PS2 Pro manuals; sampling delay set at positions "2", "3" and "4" will eliminate small surface items, ground mineralization effects and generally all the smaller targets, respectively set from lower to higher value.
Also will benefit more with larger coil diameters.
And i can "blah ... blah ... blah ..." like that to eternity.
But few people like Joseph J. Rogowski, Eric Foster and Carl Moreland already wasted so many words on this so far.
All what i can do is to repeat them. No need for that.

[ivconic]

Here comes the interesting part, which i don't understand quite well, will need clarification by someone more conversant:

[eclipse]

I haven't measured the timings (no scope right now but from these graphs) TX width is 100uS (somewhat lower than expected ~200uS).
Sample Sy is the first sample with 25us-300us delay from TX. Sx is the second sample 250us after Sy. Sample widths are 275uS which is somewhat higher than expected (200us) but I guess it's OK. Frequency seems OK. If you want try to increase TX width up to 200us for better response on large targets. Timings are easily doable with MCU.

[ivconic]

I haven't measured the timings (no scope right now but from these graphs) TX width is 100uS (somewhat lower than expected ~200uS).
Sample Sy is the first sample with 25us-300us delay from TX. Sx is the second sample 250us after Sy. Sample widths are 275uS which is somewhat higher than expected (200us) but I guess it's OK. Frequency seems OK. If you want try to increase TX width up to 200us for better response on large targets. Timings are easily doable with MCU.

Correct.
Although i measured with oscilloscope and draw those early this morning (barely awake); i think i didn't make mistake.
So, what is confusing me are those long pauses between cycles.
Long and so different between choices from "1" to "4".

[eclipse]

25-300us is the primary delay for skipping small items. 300us is rather high I think you get natural small items rejection with large coils anyway but this also reduces the amount of useful signal which is processed further I wouldn't keep it, probably ~150us (max) seems a bit more useful in my view.

3.5ms to 6.5ms (dead period) shows quite a bit dead period.
I would place Sx pulse at the end of the cycle (right before the next TX cycle) this way you won't get reduced signal for large Tc targets or just add 1ms between Sx and Sy to have better response on really long Tc targets.

[Orbit]

I was not interested in time at all but here's just the transmitter time..

[Jose]

It would be interesting to see the integrator you use to process sample pulses as wide as 275 us.

[ivconic]

I was not interested in time at all but here's just the transmitter time..[ATTACH]53589[/ATTACH]

That's strange?
How did you measure that?
Whole cycle: is TX - 1.delay - S_Y pulse - 2.delay - S_X pulse.....certain pause ... again next cycle TX - 1.delay - S_Y pulse - 2.delay - S_X pulse
Now, you shall measure the time from point where S_X pulse ends to the next appearance of TX pulse.
According to your graphic; that time from one TX pulse to another TX pulse is much shorter than what i measured last night?

[Orbit]

That's strange?
How did you measure that?
Whole cycle: is TX - 1.delay - S_Y pulse - 2.delay - S_X pulse.....certain pause ... again next cycle TX - 1.delay - S_Y pulse - 2.delay - S_X pulse
Now, you shall measure the time from point where S_X pulse ends to the next appearance of TX pulse.
According to your graphic; that time from one TX pulse to another TX pulse is much shorter than what i measured last night?

Measured at the gate irf640 pulse width 100uS time between pulses 1.53ms , I measured with a digital oscilloscope there is certainly no mistake! When I calculated the period you measured you have a longer period therefore low time 100us high time 1.53ms = Period (T) 1.63ms

[ivconic]

I'll check that again, i will perform another measurements.
I used different method of thinking.
Your is simpler and faster, just scope TX pulse and count time to next one.
I did much complicated (probably there is mistake).
I measured TX relative to 1. sample time.
Than 1. sample time relative to 2. sample time.
Than the end of 2. sample time to next TX.
While is much simpler only to scope TX and measure time between two TX pulses.
So i will do that tonight.

[Jose]

If I measure TX, channel 1 oscilloscope.
Delay first sample channel 2 oscilloscope, okay.
I think the timing of the first sample, along with the second sample, relative to the TX pulse, is what really matters.