RELIC HAWK

[Max]

However you want to do it, but the output at u6 pin 1 is at cmos compatible level, < +- 5.5V (actually it is about 5-6 vpp).

Regards,
J. L. King

Hi JL,
well as about maximum ratings it's true...4024 is 3-15V device but can run on 18V if required, with few limitation at inputs but you have to consider that a logic "zero" is anything below 2V and a logic "one" is anything above 3V... this is the typical situation for 4024 input levels...

So the direct connection will work only if the output voltage will exced both levels up and down, with voltage level from under 2V to over 3V typically.

Now , actually, this is possible but not forced by design... so if U6 pin 1 output voltage will change in way the above condition is not matched then it will not work. That's why is always better having a true level shifter there.

Kind regards,
Max

[amtech2005]

RELIC HAWK

Hello Forum
Good news:19hours to release Minelab RH $200
http://cgi.ebay.com/MINELAB-Relic-HA...QQcmdZViewItem
We can have it to see real circuit schematic!!!if somebody of the forum live in USA and can buy it for me (carl?)and for us(the Forum) , i will send money via western Union.
Alexis

Alexmex , Did you know the buyer ? The winning price was $331.79. A very good price with a total 13 bids. It went to a German Technician. So if he knows this forum we will have good news to correct a bad schematic. If not , we will still have a corrected schematic and a great project to build !!! So a very,very good price considering the new mfg. list price was $1295.00 back around 2002 or so....just wanted to post the results before we all forgot!!!........Take care everyone.....Eugene

[Max]

another strange stuff...

Hi,
I've made another discovery on RH clone...

That is: I can set it up to ignore ferrite rods and iron almost totally BUT in Disc mode only.... when I switch to all-metal it sings with everything... ferrite stuff included!

That's cause of phase shift... sure it is.

Now that's another puzzle... cause I expect that in all-metal I can get total ferrite ignoring... pure magnetic response... nothing conductive I mean but not! Dang ferrite gives sure some phase shifts there... I see it on scope.

So... still big troubles with coil and circuit...

Is the geb not working at all ? Look pretty strange or not ?

And the trouble is now... how to simulate ground conditions without magnetic minerals (so no phase shifts) to be sure geb actually works ???

A puzzle into a puzzle...

Kind regards,
Max

[eclipse]

I think there are still errors in version 1.8, MAX. According to me (and the schematic there) the generator should not work... Do you work on version newer than 1.8? Also there is written 26бр. which on bulgarian means 26 pcs x 100 nF - 2 capacitors on each IC? OMG sounds crazy, could it be

[Fred]

Hi Max,

Is this result with the modified "F" point and did you try to configure the coil differently, to adjust shifting ?
regards!
Fred.

[KingJL]

Hi,
I've made another discovery on RH clone...

That is: I can set it up to ignore ferrite rods and iron almost totally BUT in Disc mode only.... when I switch to all-metal it sings with everything... ferrite stuff included!

That's cause of phase shift... sure it is.

Now that's another puzzle... cause I expect that in all-metal I can get total ferrite ignoring... pure magnetic response... nothing conductive I mean but not! Dang ferrite gives sure some phase shifts there... I see it on scope.

So... still big troubles with coil and circuit...

Is the geb not working at all ? Look pretty strange or not ?

Max,
What is your oscillator frequency? You said it was low on the coil you made. The frequency has a great effect on the GB control. Example: at 5kHz the range of the phase shift for the GB control is 82 - 99 degrees (-8 to 9 around the 90 degree null); at 4.6K it is 89 - 105. If your frequency is below 4.5kHz you are above 90 degrees minimum setting and never be able to get below the 90 degree null point.

Before you determine that GB not working, I would get the frequency very close to the design target of 5kHz.

Regards,
J. L. King

[eclipse]

Question: Can I use normal inductor (bobine with 2 pins)
with 15mH inductance instead of the transformer?

[Max]

I think there are still errors in version 1.8, MAX. According to me (and the schematic there) the generator should not work... Do you work on version newer than 1.8? Also there is written 26бр. which on bulgarian means 26 pcs x 100 nF - 2 capacitors on each IC? OMG sounds crazy, could it be

Hi,
probably it's so... there is some other mistake in schematic, I think could be too.

For "generator" you mean maybe the oscillator ? It works with 0.56mm wire TX coil now, just use BC337 and BC327 in it, high hfe on all. The voltage is a little bit more than 16Vpp... maybe 16.2 or 16.3Vpp on 0.56mm coil I didn't read it carefully cause I expected 16Vpp there and so it's well enough for me.

I'm working on version 1.8 of schematic plus the correction at trimpot I explained before and the "f" line of above, just these 2 stuff are not in schematic, I'm awaiting for some confirmation before I put them in schematic too... new revision, cause I cannot be sure at now they are correct 100%, though this way circuit make more sense to me.

I think 266 is actually something 26@100nf meaning "26 at value 100nf"... maybe it's drawn too simplified... but it's clear the capacitors are decoupling on every ic, 13ic , 2 per ic... so 26.

Kind regards,
Max

[Max]

Hi Max,

Is this result with the modified "F" point and did you try to configure the coil differently, to adjust shifting ?
regards!
Fred.

Hi,
the device is really critical related to coil phase shifts... you slightly modify it and all change...including lot of randomic beeps from time to time.

These results are from moving "f" to the geb channel control.

I see device is not so critical about nulled voltage... could be also some volts at output of preamp... and it still work (on the bench) like when there's 100mV there but I don't know about exact phase shift required.

I found that in disc mode I can null ferrite and iron stuff about totally, if I exclude some randomic effect from time to time... the behaviour is consistent in disc mode... but when I switch back in all-metal it sounds with ferrite rods and iron ...

Now iron is ok in all-metal... but not ferrite ! So I think there's more to understand about it... probably something that works in disc mode stop working in all metal... cause all-metal channel is much more related to geb little untuning ... so far I checked for the best nulling but nothing till now.

Probably the accurancy required to gain a good null is under 1°.

Kind regards,
Max

[Max]

Max,
What is your oscillator frequency? You said it was low on the coil you made. The frequency has a great effect on the GB control. Example: at 5kHz the range of the phase shift for the GB control is 82 - 99 degrees (-8 to 9 around the 90 degree null); at 4.6K it is 89 - 105. If your frequency is below 4.5kHz you are above 90 degrees minimum setting and never be able to get below the 90 degree null point.

Before you determine that GB not working, I would get the frequency very close to the design target of 5kHz.



Regards,
J. L. King

Hi JL,
yes, you are absolutely right about phase. I've changed number of turns to get 5KHz before making such tests... now I read 4.973 Khz on oscillator.

Wire is 0.56mm resistance around 2.5ohm, turns I'm employing at TX are 45.

PS: can you post the .asc file of your simulation ? I'd like to watch at it...

Kind regards,
Max

[Max]

Question: Can I use normal inductor (bobine with 2 pins)
with 15mH inductance instead of the transformer?

I've made this way... used a neosid inductor and rewound for 15mH exact.... and works good.

Kind regards,
Max

[eclipse]

The "f" connection persists in the coinseeker like RH schematic, (looking at 1.8 version). I have high quality fotos of musketeer PCB,
before i sell it made bunch of 7Mega pix fotos, if you think they can be usefull i will post them here.

[Max]

The "f" connection persists in the coinseeker like RH schematic, (looking at 1.8 version). I have high quality fotos of musketeer PCB,
before i sell it made bunch of 7Mega pix fotos, if you think they can be usefull i will post them here.

Hi,
probably circuit is really close to RH... if you can, post them, could give some help solving the mistery of "f" connection.

If too large use rapishare.

Kind regards,
Max

[eclipse]

Check this out, I'm making new thread for XS PCB, stand by... to compress and upload

[eclipse]

Actually its not a bad idea to post them all uncompressed, high quality and nice... i don't think i can duplicate it my own, but together we could.
My idea is if we reverse musketeer pcb, we can recover the electricial schematic and from there to upgrade it to relic hawk (the differences should be minimalistic)