RELIC HAWK

[amtech2005]

RELIC HAWK

DOES ANYONE KNOW THE EXACT PART NUMBER OR ANY RESISTIVE MEASUREMENTS ON THE BLUE TRANSFORMER SHOWN . SCHEMATIC SHOWS A CENTER TAP CONNECTED TO NOTHING. AND I ALSO DO NOT SEE A SECONDARY WINDING ON THE SCHEMATIC???SO IS THE PRIMARY WINDING USED AS A CHOKE OR LC FILTER ???? THANKS...................... EUGENE

[ivconic]

15mH (L) parallel to 1uF (C)

Regards!

[Max]

DOES ANYONE KNOW THE EXACT PART NUMBER OR ANY RESISTIVE MEASUREMENTS ON THE BLUE TRANSFORMER SHOWN . SCHEMATIC SHOWS A CENTER TAP CONNECTED TO NOTHING. AND I ALSO DO NOT SEE A SECONDARY WINDING ON THE SCHEMATIC???SO IS THE PRIMARY WINDING USED AS A CHOKE OR LC FILTER ???? THANKS...................... EUGENE

Hi,
with 15mH there you have LC resonant frequency at about 41Khz... then you have two antiparallel diodes (for limiting voltage in the interval 0.7..-0.7 and also some resistor function seem quite clear to see I think: it's filter stage that will provide supply to audio tranducer (phones ...) without intermittent propagation of too spurious frequencies on supply rail... this will improve stability of amplifiers chain vs audio stage impact.

Kind regards,
Max

[amtech2005]

RELIC HAWK

THANK-YOU, IVCONIC , MAX FOR THE FAST ANSWER. I AM MAKING A PART'S LIST . AND I ALSO WANT TO MAKE A THROUGH-HOLE PCB BOARD . I DO NOT WANT SURFACE MOUNT BECAUSE OF MY BAD EYE SIGHTBUT IF THERE ARE NOISE PROBLEMS OR OSCILLATIONS I MAY HAVE NO CHOICE. I STILL HAVE A LOT OF WORK TO DO ON THIS BECAUSE I AM JUST GETTING STARTED !!!!!!!!!!. I WILL POST MY PART'S LIST FOR EVERYONE TO DOUBLE CHECK. THANKS AGAIN...........EUGENE

[ivconic]

Hi,
with 15mH there you have LC resonant frequency at about 41Khz... then you have two antiparallel diodes (for limiting voltage in the interval 0.7..-0.7 and also some resistor function seem quite clear to see I think: it's filter stage that will provide supply to audio tranducer (phones ...) without intermittent propagation of too spurious frequencies on supply rail... this will improve stability of amplifiers chain vs audio stage impact.

Kind regards,
Max

Max you are reading my thoughts! I was going just about to suggest same solution to be tested with TGS on TGS thread!
As i posted earlier, there is certain relation between some ocassional chatters and choice of speaker at TGS. With 16 ohms speaker TGS have less and rare chattering than with 8ohms. Even more, if you put extra 10 ohms resistance in serie with speaker those chatters will disapear for good, but audio will be very mum and weak. So first time i spotted this at Relic Hawk, i wandered what would be if....
Worth of trying!

[Geo]

THANK-YOU, IVCONIC , MAX FOR THE FAST ANSWER. I AM MAKING A PART'S LIST . AND I ALSO WANT TO MAKE A THROUGH-HOLE PCB BOARD . I DO NOT WANT SURFACE MOUNT BECAUSE OF MY BAD EYE SIGHTBUT IF THERE ARE NOISE PROBLEMS OR OSCILLATIONS I MAY HAVE NO CHOICE. I STILL HAVE A LOT OF WORK TO DO ON THIS BECAUSE I AM JUST GETTING STARTED !!!!!!!!!!. I WILL POST MY PART'S LIST FOR EVERYONE TO DOUBLE CHECK. THANKS AGAIN...........EUGENE

Hi Eugene.
I have the same problem with my eyes (48 years old) so i am waiting for a through-hole pcb design. If you will draw it then please post it here. I thing that it is time to constuct this Big machine.....
Regards

[ivconic]

Luck, i dont have problems with my eyes.... , but my skills over smt are very poor ..., so me too - i would like to see here accurate through hole pcb. Dont have enough time to draw one, right now...
Regards!

[Max]

Max you are reading my thoughts! I was going just about to suggest same solution to be tested with TGS on TGS thread!
As i posted earlier, there is certain relation between some ocassional chatters and choice of speaker at TGS. With 16 ohms speaker TGS have less and rare chattering than with 8ohms. Even more, if you put extra 10 ohms resistance in serie with speaker those chatters will disapear for good, but audio will be very mum and weak. So first time i spotted this at Relic Hawk, i wandered what would be if....
Worth of trying!

Hi,
yes I think too it's worth cause I noticed too that lower impedance speaker give problems. I find so far just some 16ohm speakers works fine on tesoro's (bandidoII and tgs) and just a few of 8ohm speakers could be used really on them cause of chatters appears.

I have maybe 100 different 8ohm speakers and maybe (not tested 100!) just 20-30% seems are usable on tgs cause larger ones gives problematic behaviour... chatters.
Probably the oscillations of coil in the permanent magnet area is sustained too much in larger ones and that produce at 8ohm too much troubles on supply rail. On some smaller I noticed problems are less but still there.

I think the filter is a good idea but then we must use an headphone I think cause we also reduce signal strenght cause of resistance etc

Anyway, it's something that probably will make even more stable tgs than it is already.

Kind regards,
Max

[Max]

Max you are reading my thoughts! I was going just about to suggest same solution to be tested with TGS on TGS thread!
As i posted earlier, there is certain relation between some ocassional chatters and choice of speaker at TGS. With 16 ohms speaker TGS have less and rare chattering than with 8ohms. Even more, if you put extra 10 ohms resistance in serie with speaker those chatters will disapear for good, but audio will be very mum and weak. So first time i spotted this at Relic Hawk, i wandered what would be if....
Worth of trying!

Hi,
yes I think too it's worth cause I noticed too that lower impedance speaker give problems. I find so far just some 16ohm speakers works fine on tesoro's (bandidoII and tgs) and just a few of 8ohm speakers could be used really on them cause of chatters appears.

I have maybe 100 different 8ohm speakers and maybe (not tested 100!) just 20-30% seems are usable on tgs cause larger ones gives problematic behaviour... chatters.
Probably the oscillations of coil in the permanent magnet area is sustained too much in larger ones and that produce at 8ohm too much troubles on supply rail. On some smaller I noticed problems are less but still there.

I think the filter is a good idea but then we must use an headphone I think cause we also reduce signal strenght cause of resistance etc

Anyway, it's something that probably will make even more stable tgs than it is already.

Kind regards,
Max

[Max]

Luck, i dont have problems with my eyes.... , but my skills over smt are very poor ..., so me too - i would like to see here accurate through hole pcb. Dont have enough time to draw one, right now...
Regards!

Hi,
we must consider also many people here have just "normal/old" components kind not smd. So the good idea is making first a throughole design... so different people will start building it and find bugs if any... start tuning etc etc and we'll spot problems easy with such a design.

Then if someone need smd that could be made as alternative design to keep things smaller and lighter... but just after end-up with device working.

Personally I still prefer old style than smd cause not only eyes stress but about the fact removing stuff from smt board is not as easy (sometimes is painful experience) as with old stuff... so to experiment...change stuff, try different is better having e.g. old style passive components and sockets for ics etc etc

I'm sure you agree with me on this...

Kind regards,
Max

[amtech2005]

RELIC HAWK

WHEN I WORKED ON BROADBAND AMPLIFIERS FOR CABLE TV , NO ONE TAUGHT ME HOW TO WORK ON SURFACE MOUNT PROCEDURES AND I HATED IT.WHEN I FIRST GOT STARTED I USE TO BREAK SMT'S WITH TWEASERS, ALSO OVERHEATED THE SMT DEVICES AND THE FOIL ON THE BOARD.IT TOOK ME TIME LEARNING THE HARDWAY AS USUAL. BUT ANYWAY I THINK THE NUMBER ONE PURPOSE OF SMT IS SAVING SPACE AND ALSO IT HAS LESS STRAY CAPACITANCE AND STRAY INDUCTANCE PROBLEMS. NOISE PROBLEMS HAUNTS US ALL , IF YOU COPY A PERFECT WORKING PCB CIRCUIT BOARD "THE PART LOCATION'S "MUST BE IDENTICAL" TO THE ORIGINAL PART'S LOCATION OR YOU WILL HAVE EXTRA PROBLEMS THAT YOU DON'T NEED!!! LIKE THE ORIGINAL GOLDEN SABRE HAS GREAT DISCRIMINATION AND IT'S DEPTH IS VERY GOOD. AND IF THE NEW CIRCUIT BOARD'S BEING MADE ARE IDENTICAL TO THE ORIGINAL GOLDEN SABRE PCB BOARDS THEN THE NOISE PROBLEM IS A FAULTY COMPONENT OR COMPONENT VALUE OR THE SEARCH-COIL IS NOT RIGHT. THANK-YOU MAX , IVCONIC, GEO, AZIZ,CARL, TINKERER, THE WIZARD, AND EVERYONE FOR HELPING TO MAKE GEOTECH FORUM AND HOBI-DETEKTORI FORUM SO GREAT!!!!!!!!!!!!..............TAKE CARE ALL.......................EUGENE

[Geo]

Hi Eugene.
I am waiting for the parts list. I want to check it.
It is long time that i did not make anything, so i want to try to help you to design the pcb. Ivica and Max have made a lot of things at this forum so it is our time
Regards

[amtech2005]

RELIC HAWK

GEO, IT MUST BE A THROUGH-HOLE AND IT MUST NOT BE THE "COINSEEKER 2".. COINSEEKER 2 HAS LOST DEPTH BECAUSE THEY DOWN-SIZED AND CHANGED THE SCHEMATIC. AND CHANGING THE AUDIO DID SOMETHING TO THE CIRCUIT GAIN . THEY ALSO TOOK AWAY ALL CONTROL SWITCHES. I AM JUST STARTING THIS PROJECT, SO PLEASE BE PATIENT.SEE POST #53 AND POST#59 ON THIS PAGE OF THE RELIC HAWK , AND SEE THE SIMILARITIES AND SEE WHAT IS MISSING. I AM A GOOD ELECTRONIC REPAIR TECH ON REPAIRING EXISTING DEVICES .BUT NOT A DESIGNER AND I AM NOT A SCIENTIST !! YET. I DO HAVE 2.0 MEGABYTES OF PHOTO'S AND FILES ON RELIC HAWK I CAN E-MAIL TO YOU, BUT THEy ARE JUST BITS AND PIECES OF FILES. I WILL START ON THE PARTS LIST TONIGHT AND TOMMORROW. ANY PROBLEMS I WILL LET YOU KNOW AND KEEP YOU POSTED. ........THANKS..............EUGENE

[Geo]

OK Eugene.
I sent to you my email
Regards

[amtech2005]

RELIC HAWK

GEO, I WILL SEND IT ASAP ,IT IS SMALL ABOUT 1.5 MEGA-BYTES . BUT I THINK YOU HAVE MOST OF THE INFORMATION ALREADY. I ALSO HAVE ABOUT 3 OR 4 FULL DISKS OF ABOUT 2 GIGA BYTES OF DETECTOR SCHEMATICS , PHOTOS , PDF FILES OVER THE LAST 3 YEARS ,BUT THEY ARE ALL MIXED UP AND NOT IN ANY ORDER , A BIG MESS !!!! . WHEN I GET TIME I SURE WOULD LIKE TO COPY THEM TO PAPER AND PUT THEM IN A FOLDER AND LABEL EACH ONE.. ANYWAY I WILL SEND YOUR SMALL FILE , AND THEN I WILL BE VERY BUSY FOR A FEW DAYS WORKING ON THIS RELIC HAWK ALSO !!! TAKE CARE..............EUGENE