RELIC HAWK

[Max]

Hi,
I have good news... not that's all working absolutely ok but read...

I've changed the GEB pot for 10turns and then regulate it in disc mode to null ferrite... and works very nice... I can null in a way ferrite stick is ignored at 1cm from coil, no sound... nothing.

Same happens to iron. Then I could still hear small cracks when iron (hammer) and ferrite rod are at 15cm or more... but I think is problem of something that saturates etc...

Now I tested for all-metal trying to do the same, since now there's a 10turn thing...

I reduced sens at 70% and got similar results... though not really as when in disc mode, 2-3cm no sound... but less there's sound... BUT before was very worse ... much more than this.

The iron instead is detected from far, like copper or aluminium AS EXPECTED.

So seems GEB works... only problem is that device it's really more sensitive to ferrite when in all-metal... in a way I cannot null better than 5-6cm when put sens pot to maximum...

I think this could be a weakness in design and sure, if it is, owners of RH must know that in all-metal they get more false signals from soil, more easy.

I say this cause I saw TGS ignore ferrite just under the coil... but, sure, power is less in TGS... we must consider this too.

What do you think ?

Kind regards,
Max

[Fred]

Ferrite contains iron ,so even if properties are different from it it may work on regular soil but not on ferrite.
It alslo probably depends of ferrite properties.
Fred.

[Max]

Ferrite contains iron ,so even if properties are different from it it may work on regular soil but not on ferrite.
It alslo probably depends of ferrite properties.
Fred.

Hi,
you are right Fred. I see a phase shift that occours when I lower much the ferrite rods... so, we know any phase shift will give an useful signal...for the MD... and an audio response if strong enough.

My dubt is about TGS... I have mine handy and today tested again and again with same rod... and it ignores that ferrite so easy!

But I think RH is much more critical device, more powerful TX etc... I mean... a few fraction of degree of shift and you'll get the beep... probably TGS is more tolerant with that issue and thus the better ferrite ignoring cause need larger phase shift or nearest rod to get into troubles.

Do you agree ?

Kind regards,
Max

[eclipse]

nakky i can't make more fotos because i sold the device long time ago. i bought eureka gold which turned to be child's toy for finding coins and nuggets under the carpet...
I do have coinseeker board, if you need tips i can check the things you need.

[nakky]

Eclipse,thanks,but I think its OK now.Grt Nakky.

[KingJL]

Max,
What are the physical dimensions of the 15mh inductor in the audio circuit? I am asking because I see some ferrite E-Core(s) on ebay. There are two different sizes and I'd like to know which one to get.
Thanks,
J. L. King

[ivconic]

Musketeer and Rh are very simillar. Thus Musketeer could be adopted as lite version of RH. Working frequncy is 7kHz and at RH iz 5kHz.
90% of designs are identical.
So...look at output stage, there are BC547C and BC557c with that unknown transistor.
Bulgarians did not deciphered it and than used BC337/327 combination on their Coinseeker 2 Pro.
Few days ago i got brand new Coinseeker 2Pro pcb with all components soldered. It is not working? Dead!? I tested it with original RH coil.Not oscillating. Power drain is 20mA? Nothing warm or burns. No oscillations....
Powers supply lines are ok. Everything seems to be good. Yet not working.
So...my doubts are still on those transistors....
It is obvious that ordinary BC547C and BC557C can work there as far as last (smt) transistor is properly choosen.
Instead using various other transistors and "push" this to work, i would rather rethink and decipher original smt transistor and find its eventual replacement.
I also had Musketeer Colt in the past. And RH. Also inspected those pcbs...nothing strange nothing from Mars. Yet...these handamades refusing to work!?
Sheesh!

[eclipse]

This is not a transistor but diode, i checked it before when i had it.
The freq of the XS is the same as RH - 5Khz/15V

[amtech2005]

RELIC HAWK

Eclipse , Nice work on all your photos. But when I opened the Muskateer .Lay file , I only saw a few components on left side of the circuit board !! Is the lay file complete , or do i need to test my Sprint with another file ??? And also like I said all along the Muskateer is a Down sized and modified version of the Relic Hawk !!!! And to verify that little SMT with a question mark on the photo , somebody needs to check with an Oscilloscope to see if it has Gain or no Gain between in/out !!!! If not , than Fred/Max/Ivconic will come through for us , they always do!!! I believe the 5 khz oscillator circuit of the Muskateer has been "Re-Designed" to have a lower "power output" than the Relic Hawk !!!!!....................Eugene

[Fred]

Hi Ivconic,
this transistor or diode must have some number on it??
If the oscillator is working fine with a trnasistor,i wonder how it would do with a pair of diodes instead
Maybe if you take off the varnish you can see the reference.
Regards,
Fred.

[eclipse]

the board is unfinished, i had to remove all components from the board to
be successfull and i didn't want to do it... then, right now if i had it i probably would.

[KingJL]

124 to 248 = 304 to 428 (really 60) when you take into account 180 phase shift from GEB. Now when shift 90 degrees to get center you have:
-30 to 214
Simulation results (adjusted for 180 difference between GEB and DISC and then 90 degree to center of gate):
GEB -12 to 7.5
DISC -30 to 210 @ -12 GEB, -43 to 228 @ 7.5 GEB

Calcuilations have to be all wrong. I have recalculated (don't ask me how, because I am not sure I could do it again). In combination with reading the manual, observing the simulation traces and the observing the simulation AC analysis I have determined that: with GB set for 90 degrees at the phase detector, DISC varies from 127 to 245 (-115) degrees. This would correspond to the following at the CENTER of the gates: GB = 0, DISC varies rom 37 to 155 degrees.

This would agree with the manual which states that:
"With the Discriminate control at its minimum (fully counter clockwise) setting, most low conductivity targets, i.e. small ferrous items such as bolts and nails, will be eliminated but larger ferrous targets may still be detected."
...
"With the Discriminate at its maximum (fully clockwise) setting, large silver, brass, copper, and lead targets (which are highly conductive) will not be discriminated out."

It just so happens that a small nail is ~20 degrees, a large nail is ~40 degrees, a silver dime is ~155 degrees, a quarter is ~160. That lays right in with the observed phase shifts in simulation. A DISC phase shift of 37 to 155 degrees would also agree with the operational description given in the manual.

Whew, that was a 'round about way to arrive at the answer!!!

Regards,
J. L. King

[Max]

Max,
What are the physical dimensions of the 15mh inductor in the audio circuit? I am asking because I see some ferrite E-Core(s) on ebay. There are two different sizes and I'd like to know which one to get.
Thanks,
J. L. King

Hi,
I don't know exact dimensions... I've made my own inductor for there, small one , using a neosid inductor core that's about 1cm long...

It works but probably is not the best about audio power.

I'm using 16ohm speaker ... I hear it but it's not so loud.

Kind regards,
Max

[Max]

Musketeer and Rh are very simillar. Thus Musketeer could be adopted as lite version of RH. Working frequncy is 7kHz and at RH iz 5kHz.
90% of designs are identical.
So...look at output stage, there are BC547C and BC557c with that unknown transistor.
Bulgarians did not deciphered it and than used BC337/327 combination on their Coinseeker 2 Pro.
Few days ago i got brand new Coinseeker 2Pro pcb with all components soldered. It is not working? Dead!? I tested it with original RH coil.Not oscillating. Power drain is 20mA? Nothing warm or burns. No oscillations....
Powers supply lines are ok. Everything seems to be good. Yet not working.
So...my doubts are still on those transistors....
It is obvious that ordinary BC547C and BC557C can work there as far as last (smt) transistor is properly choosen.
Instead using various other transistors and "push" this to work, i would rather rethink and decipher original smt transistor and find its eventual replacement.
I also had Musketeer Colt in the past. And RH. Also inspected those pcbs...nothing strange nothing from Mars. Yet...these handamades refusing to work!?
Sheesh!

Hi Ivconic,
it's the same problem I had... if you use a thicker wire coil you'll see it oscillate if everything is ok about circuit you have.

I think the transistor could be anything there... but we can expect will be a real problem identify it cause we don't have nothing more now that pictures... and there I see no label about it.

I think the best way to discover what is it is by smart handle analyzers... that could tell directly the transistor kind if connected to its leads... something woody.au made about sd2000 if I remember well... but I think the last test would need dismantling the piece from a board.

Probably it's something not so strange or unusual... maybe some BC827 smt version or BC807... something you can see in old TVs.

Kind regards,
Max

[ivconic]

This is not a transistor but diode, i checked it before when i had it.
The freq of the XS is the same as RH - 5Khz/15V

It is transistor not a diode! You checked something other!?
Maybe you forgot. Maybe you checked those 2 diodes in same case at audio output...
Think again..

I had Musketter Colt (older than XS) and its frequency was 7kHz. Do not ever have doubts in my words.
Every possible detector i ever had (over 50 originals) was checked and tested in all possible situations.
Almost 20 years i am forming sort of database on detectors i had chance to use.