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Ivconic,
Did you wind TX and RX in same direction?
Ivconic,
Did you wind TX and RX in same direction?
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Yes.Originally posted by tiktak View Post
Cose possibillity to mix up and forget those, i alway mark start and end, also RX and TX coil. Once you "coated" those with F.cage it is gonna be hard to distinguish which one was start or end. TX and RX are hard to confuse. You can alway use unimeter and measure inductance or resistance on those.
While aasembling, i turn those many times in my hands...at the end if not marked i wouldnt know exactly where is start or end? Tricky! Pay attention.
When laying coils in housing i stricktly pay attention to arrange those to be turned properly. If wounded in same direction (must) than when layed in housing, ends are in oposite directions. Start are facing ends etc..
Actually i never tried other ways? I am not saying this is most proper way, i am using. Probably other ways are possible. But this one i used from a start and it is working for me....
255x137 is coil itself, 270 is housing (also known as Bulgarian, here in Serbia)
that's why you can see, sometimes, in some posts, 27cm is noted...
We mean same coil....diferent way to explain it
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Hi,Originally posted by tiktak View Post
dimensions are as you can see in my pictures... it is correct making that design... and coils work really good.
Of course, for on real soil usage you need to reach at least 5mVpp nulling (less is better) cause that way your unit will be more stable respect to false signals due to soil mineralization even with not perfect GEB settings.
About winding coils... yes I wound always in same direction... but it's not important: you can always reverse leads of RX if there are phase problems then after when you put coils into the housing.
Kind regards,
MaxComment
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Max, I have come up with a multi harmonic I /Q demodulator like on the ML's. It takes first the four harmonics from the Tx wave. I will try to draw it up and post it here sometime soon for you. May be useful IF you are thinking of using a square wave, but you will have 8 lots of filters to sum or process at the end, so I hink you might want a PIC or Atmel device to calculate the various phase angles.
On the version I have come up with, you can also change the Tx frequency as it uses a PLL to derive the Tx frequency, not sure if part of it will work as the I/Q split is done PRIOR to the 161 counter / dividers I am using.Comment
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Hi Sean,Originally posted by Sean_Goddard View Post
really interesting: does the multifreq. demodulation give the ability to understand better about target composition/detection in worse cases e.g. when an iron and oxides things are near like happens in trashy/infested sites ?
What about power at TX ? Does it use bridge configuration like some MLs do ?
Kind regards,
MaxComment
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Royal Sabre!
Hi Max, Ivconic and others,
I think that Royal sabre is better than Golden sabre. Here is its shematic:
Tesoro Royal Sabre.pdf
It has additional controls like pinpoint etc.
What do you think? Both are similar... so you can simply try Royal Sabre on your Golden sabre pcb.
Regards,
1843Comment
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This .pdf is corrupted. Post it again...Comment
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Originally posted by ivconic View Post
Sorry! It is not corrupted....i had problems with my Acroread, now is fixed...
Sorry!
Regards!
BTW thanks for schematic..
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Max, take a look on this schematic!! I seems you had right! There is 51pF...
So first thing i should do is to replace 330pF with it...to check for sinus there..
Be back...Comment
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Whats going on Here
Whats going on Here 46,000 views,15K replies, whats the speciality of this ckt in numerics.....Comment
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Royal Sabre
Hello Frends.
The Royal Sabre is not the same as the golden pcb.
Think it is not a good project to make !!
Keep it simple.....
Best regards.
ApComment
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Hi,Originally posted by ivconic View Post
look at frequency: 12KHz at that frequency and with 57pF the output at pin1 will be sinusoidal for sure.
Our "problem" with the 100pF cap is about frequency and reactance at cap... lowering a bit the frequency to 14KHz could solve it... but we need changing coil or caps params at osc. Much better changing the cap at LF353 pin2 using something 47 to 68pF to gain same undistorted wave.
About 12KHz , we have same caps in oscillator in that schematic, so I guess that who made schematics referred to a particular coil used with it that gives tx at 12KHz.
The pinpoint mode is somehow similar to bandidoII : like an all metal non-motion with manual retune.
The Royal had also a kind of 2 tones ID... using notch for setting the disc threshold between bad/good metals... like in golden sabre plus.
Kind regards,
MaxComment
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Hi Ap,Originally posted by ApBerg View Post
I totally agree. It will be better making e.g. BandidoII than Royal... even without "2 tones"... but with non-motion all metal for pinpointing (and motion all-metal too) than it.
But problem with bandidoII could be ED-120 discrimination that is no good for me... so one have to modify disc to get the D-90 like in TGS. Just this will be enough.
The fact that "2 tones" of royal depends of notch setting is also another worse thing to me... it will be much better having a two tone calibrated on a specific phase angle or having more than 2 tones ...3 or 4 with just one lower freq for ferrous stuff/unwanted.
Kind regards,
MaxComment
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about 2 tones generation in royal sabre
Hi,
this post just to explain the trick of two tones in royal sabre...
How it works ?
First of all you can notice there isn't any cd4024 in it that gives the frequencies for audio tones... the source of tones is the supply voltage converter ICL7660.
The ICL7660 has an input, pin 7, for the connection of an external capacitor that dictate the frequency of operation (from few KHz to 10KHz in standard 7660).
Now you can see in first picture the frequency obtained vs capacitance. Look at the higher freq. part you'll notice that with 100pF one get about 1KHz frequency and at about 80pF one get about something less 2KHz.
All it's related to the capacitance at pin 7 that could be 82pF or 92pF depending on the status of conduction of the TIS75 fet.
When in DISC mode , setting a value at notch pot , is possible defining a level of phase passed over or under which one or both capacitors are connected to PIN7 thus giving the two tones.
The frequency separation is of some hundred Hz and probably has no great influence on other parts of circuit , cause 7660 is an efficient device...and so voltage will vary a few from the low frequency to the higher and the reverse from hi to low.
This approach could be replicated in standard TGS using a VCO ic like the LM566 or e.g. an CD4046 internal VCO etc.
It is any good ? I have lot of dubts on it... my first problem with it is that the two tones separation threshold value is related to manual adjustment of the notch pot... that for me is a bad idea... the best will be adding 2more channels to get similar behaviour but with a fixed preset...
but then also the circuit start becoming complex.
Kind regards,
MaxComment
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What do you say to modify the TGS??
If we add a channel for Pinpoint ?? (the upper LF442 from Royal)
Regards
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