RELIC HAWK

[Max]

TikTak thanks,
original RH does not have speaker, only earphones.

Quiaozhi i was thinking the same way, only didnt want to bug to much; most of my doubts are on coil Max used there.
My problem right now is due i dont have proper wire gauge to perfom detailed experiments and finally establish most accurate datas for RH coil. But i am pretty close.
Need to keep resistance arround 40 ohms for RX and inductance 15uH on 30cm former.
I guess TX part would be much easier to distinguish and make.
Actually piece of cake. Only 35 windings on 30cm former must give 3.1 ohms and 1uH inductance. So....0.5 to 0.6mm would do the job just fine.
At the end only one thing left; proper residual voltage?
Also easy job. I intend to make only TX part on perfboard, connect to original coil and measure residual voltage at RX outputs.
Must obey 5kHz frequency for proper readings.
Once we get proper datas, it would be even easier to calculate smaller diammeter coil - my preferables! Yup!
As original 35cm is a way to large for my taste. I intend to make 24cm coil for RH.
MAX...come to think....how about LS204 opamps? Obsolete, but i have few in my scrapbox.
Regards!

Hi Ivconic,
I think ls204 are good for it... not about consumption or strictly speaking fully equivalent to ts27m2 but I think they will work good too.

I was thinking too at coil... but don't know how to check for phase stuff on this... cause I can just null good... and few movements make the coil get too much signal at preamp inputs...

The disc channel sample the signal and seems good, so I think I must check signals for some mistake in pcb or schematic but till now I found nothing about.

Qiaozhi is probably right, the all-metal works good cause of the direct, single channel operations... but when both channels are connected and compared device stop working good.

Kind regards,
Max

[maxbiri]

I Max
I had the same problems when i built eldorado and silver, they work very whell in all metal but not in disc.
The problem was the phase shift tx rx with small difference thre were big difference in disc.
But for check phase difference you need a dual trace oscope.

Maybe you have the same problem on RH.

Bye Maxbiri

[Max]

I Max
I had the same problems when i built eldorado and silver, they work very whell in all metal but not in disc.
The problem was the phase shift tx rx with small difference thre were big difference in disc.
But for check phase difference you need a dual trace oscope.

Maybe you have the same problem on RH.

Bye Maxbiri

Hi,
yes , phase is probably involved but not only... must be something else too.

I'm doing some checks at now but sampling seems good and I'm a bit confused about that, cause detector works really bad in disc mode.

Kind regards,
Max

[Fred]

The TR51-ph7 is a BSR51 transistor, npn darlington + internal diode, we can use BC517 or C517 or similar without much problems.Kind regards,
Max

Hi,
I mean the one on page #1 of this thread, labeled "relic hawk 1".
No , I changed for BC337, BC327 at osc, they work good.
The BC517 is instead of darlington BSR51 at audio stuff, not labeled in schematic.
Kind regards,
Max

Im´confused,i thought the bc517 was the trick for good oscillation with higher resistance coil.
thanks too nakky for answer about schematic on 1st thread.

regards,
Fred.

[Max]

Hi,
I think problem is around op amps selection... using some different op amps I found there's an improvement , this expecially about U4 and U8... but problem is that disc works still bad way...no good.

I mean... I can disc now a bit... but iron stuff still give beeps from time to time and at particular distances...so it's not reliable...I've used some ne5532 at U4 and U8, but I also found that mounting some NE5532 I get better than with others... same brand (philips) same model! Dang!

Very critical this circuit!

The sensitivity in disc mode is still poor compared to all-metal.

Maybe ML used some special phase alignement at coil ???

Who knows ?

I'm also smoking the dang cigar now... and nothing come in mind about all that troubles...I see at disc mode!

Also... make sense to you the motion/no-motion there ??? Seems a bit odd...by the way...also this feature doesn't work!

Kind regards,
Max

[Max]

Hi Max,

Have you checked whereabouts the DISC channel is sampling on the RX signal?
Also, is the GEB channel sampling at the zero-crossing point?
If not, then the phasing on the coil is probably incorrect.

Hi,
GEB is at zero-crossing... I mean... the control pulse has its middle at zero-crossing of RX signal... that is what you mean I think. So seems good.

Disc is instead about 90° shifted but I must check again... for movements using the disc pot. I noticed spurious sharp communtation at some pot positions... but just 2 positions, all the others are ok.

I think disc control timing is probably correct... but maybe coil need particular phase shift of RX signal. I don't know if coil I've made can fit particular phase requirements if any.

Kind regards,
Max

[Fred]

Hi,
I mean... I can disc now a bit... but iron stuff still give beeps from time to time and at particular distances...

This is LRL effect.Probably some gold staue 20km away...

Also... make sense to you the motion/no-motion there ??? Seems a bit odd...by the way...also this feature doesn't work! ...

Should work :when in motion mode the 1uF cap value (kind of memory) discharges via the 22k resistor.When in non-motion it only goes thru the 10M ones,(so keep charged ), "reset" just temporarly connect it to the 22k resistor.

Ps : i swap a hat like yours for a semi-populated RH PCB ...you can keep the cigar.
regards,
Fred.

[Max]

This is LRL effect.Probably some gold staue 20km away...


Should work :when in motion mode the 1uF cap value (kind of memory) discharges via the 22k resistor.When in non-motion it only goes thru the 10M ones,(so keep charged ), "reset" just temporarly connect it to the 22k resistor.

Ps : i swap a hat like yours for a semi-populated RH PCB ...you can keep the cigar.
regards,
Fred.

Hi,
yes sure... SHOULD work... but actually it doesn't... even using jfet input stage op amp at U7! 10^12 ohm and nothing good happens... like that capacitor will hold the charge...

Sorry... I think I couldn't make another of these boards for a while... last double layer presens I've used for mine... but I can exchange some TLC27M2 or TS27M2... for some more cigars... of cuban legs rolled kind.

Sure I will keep the cigar... the fog could give some clue of what's going wrong about disc...

Kind regards,
Max

[Fred]

Hi,

Sorry... I think I couldn't make another of these boards for a while...

Actually i have the board, i want the hat !
Tnx!
Fred.

[Max]

Actually i have the board, i want the hat !
Tnx!
Fred.

Oh, wow... but I have the board too... so I think I will leave the hat on

so smoke will also confuse my vision a bit... and I will maybe find the dang mistake by fingers!

What do you think of the motion-not-motion that is also not-working ???
Isn't strange the dang stuff doesn't work at all ???

Kind regards,
Max

[Fred]

Hi Max,
No i have not really an idea.
The non-motion only works in all metal, and it is the 1u cap that transmits the signal.So i cant see how connecting a 22k resistor or not doens´t make any difference??.
When it works is it working like motion or non-motion?
did you check the +/- 2v5 at extremes of 100K trimmers? also is the "c" correctly switched from -2v5 in all metal to the output of U7...this are the tests i would begin with, but you probably have already have made a lot o them....
Maybe some mistake in switches wirings? it´s so easy ...
Hope you can find something.
regards,
Fred.

[Qiaozhi]

Hi,
GEB is at zero-crossing... I mean... the control pulse has its middle at zero-crossing of RX signal... that is what you mean I think. So seems good.

Disc is instead about 90° shifted but I must check again... for movements using the disc pot. I noticed spurious sharp communtation at some pot positions... but just 2 positions, all the others are ok.

I think disc control timing is probably correct... but maybe coil need particular phase shift of RX signal. I don't know if coil I've made can fit particular phase requirements if any.

Kind regards,
Max

If you can adjust the GEB control to sample at the zero-crossing of the RX signal, then the coil phasing is probably ok. In that case, try monitoring the output of the DISC sample gate, and note whether the amplitude changes in a different direction for ferrous and nonferrous. The DISC sampling point will then be somewhere around the peak of the RX signal. i.e. 90 degree offset from the GEB sample pulse. If this is working ok, then there is most likely an error in the design further along in the DISC channel.
Unfortunately I don't have time to follow along by building this project, but I may be able to assist with the debugging.
Good luck.

[tiktak]

Hi

Hi,
I just looked again that comparing chart of detectors depth that someone have posted here.
XLT
have almost double depth compared with RH!Minelab RH is no more on tird place there.
If we wana make something impresing this is it.Combined PI techology+.............
So.Can we do it?
Have anyone opened such device?
Thanks

[Fred]

RH Pro V.99.8 II special

Fred.

[ivconic]

Nice pcb! Neat work!
.........

XLT....Yup!

No wonder i switched to Eagle Spectrum recently! It does make difference for real! Only problem is i can not copy it...to complex for me. Also i dont have firmware for those two uPc's...

Look this photo and enjoy!