Cross reference Parts numbers please

[Micheal]

I cant find these parts to replace for my XL 500 i am trying to fix desperately ..can somebody please help me with other parts I can replace them with ...
the parts numbers are...

CA3140E
LT1037
CD4016BE
NSDU45 (8611)

If you can help I will greatly appreciate it Thank you guys

[porkluvr]

Micheal,
I don't want to lecture you but you're not supposed to just start replacing every component you can find a replacement for. That is not generally accepted as a smart troubleshooting technique.
If you beg, borrow,- or steal an oscilloscope, they are not that difficult to use. Don't break your machine any more.

Stop it, Stop IT, STOP IT STOPIT STOPPIT, PLEEEASE! STOP.

Hmmm, it occurs to me: if you get the XL500 working again - after all the major parts have been replaced it would probably be due a timing and voltage offset calibration. Have you planned on that? Don't expect to blindly turn potentiometer screws and get lucky. Is there a repair shop handy?


Confucius say:
YOU can lead a horse to water, but you CAN'T make him drink.

[WM6]

YOU can lead a horse to water, but you CAN'T make him drink.

yes, bu you still can find replacement for it

[porkluvr]

can somebody please help me with other parts I can replace them with ...
the parts numbers are...

CA3140E
LT1037
CD4016BE
NSDU45 (8611)

I would be killing you with kindness to tell you this but the damage is already done so...

if you can't find the first three parts you are looking in the wrong places. The CA3140 is an old, OLD part, (almost as old as me ) but is still listed at Digikey (and many other places), as are the next two parts. I don't have a clue what your NSDU45 is or what it does.

Digikey ships pretty much world-wide.

The LT1037 is your preamp. If you replace that, I believe you would need to do a receiver offset voltage calibration. I can't tell you the proper procedure and, you probably do not have the proper equipment. Do not replace the LT1037 unless you know for sure that it is defective. Else, you might have two problems - if you don't already.

The CD4066 is probably safe to replace with no adjustment needed.

I think CD4066 break fairly often so if you are hell-bent on replacing parts that would be a good start. You could also probably replace the CA3140 with no re-calibration needed.

You must be particularly careful with handling the CD4016 and CA3140 because they are CMOS devices and easily zapped.

The suffixes after the main body of a part number generally USUALLY indicate temperature grade, and package (DIP-8, DIP-16, etc.). The CDxxxx series parts also use a "B" to indicate that they have "Buffered" outputs. That seems a little unnecessary to me because I have never seen an unbuffered CD4016, but, who knows... .

The point of that last paragraph is that different manufacturers will use different suffix letters to indicate the same parameters, i.e., one manufacturer might uses "N" and another use "P" to indicate DIP-8, and etc. etc.. It is usually OK to deviate from the original manufacturer when you replace parts (so long as you cross-check datasheet) but it is also generally a good idea to have the proper TEST EQUIPMENT before you start replacing critical components.

It is good to see "BEFORE" and "AFTER" waveforms and voltages so that you can know that you fixing the problem better instead of making it worse.

edit: The "8611" on your NSDU45 (whatever that is) is probably a date code and is extraneous information when looking for a replacement.

[Micheal]

Thanks for the replies guys ...problem fixed by simply placing it in the rubbish bin.i dont need it any more
Porkluvr have a look at theBRN Pi-1 DİJİTAL Pİ that I finished recently...works great and was very easy to build ...just needs a bit more depth..

http://www.geotech1.com/forums/showthread.php?t=15886



I might have to change my username to micheal fiddler

[porkluvr]

Don't do it!

...problem fixed by simply placing it in the rubbish bin.i dont need it any more
<snip>
I might have to change my username to micheal fiddler

You were kidding, right? RIGHT? You'll just throw the baby out with the bath water?
Heck, save the case and stem, coil and everything.

You might be able to sell the defunct unit on ebay for a decent price. Some folks won't mind a 'fixer upper'. Somebody with a JOB and some MONEY (um not like me). Just let 'em know it is broken or somebody might get mad at whoever put you up to it.

If you are serious about learning to fine-tune metal detectors you should not be using the XL500 to fill the rubbish bin.

[Micheal]

Hi porkluvr...help me out with my new project and ill post the guts of the xl 500 out to you if you like...just what will fit in the post packaging no stem or coil or cover just whats in the box itself ,im sure you can fix it and get it working again in no time .....I am actually using the 2 coils from the xl 500 on my new project I finished the BRN1-PI.......

All I want is more depth out of this brn-pi1 it should be a piece of cake for you its a very simple setup... some mods that will work....I actually had it picking up a 20cent coin from 40cm with the small 18cm coil but I lost the configuration whilst I was tidying up the wiring and I cant get it to do it again.I am soooo upset.

What do you say is it a deal...

[Micheal]

all you have to do is add power and a coil

[porkluvr]

Provided that you know the procedure for setting amplifier offset-null (the 100k trim pot) you might want to replace the LM358 with a decent dual amplifier.

NE5532 comes to mind. If you don't have that then use MC4558/RC4558, or maybe TL072/MC34001/LF353 (same/same). These second choices aren't great but they may be better than what you have.

Other than that you should probably have a scope to really make the most out of any home-brew coils. As you play with different coils, there are all kinds of things that affect the proper choice of a damping resistor . There is no way I can help with that

[Micheal]

HI porkluvr yes I know how to use the 100k trim pot ......so is that a yes if so heres the link http://www.geotech1.com/forums/showt...9666#post99666

[porkluvr]

I won't hold you to any deal.
I went to the site you posted. I dowloaded the two PDFs that I saw and they were pretty much blank. Point being, the schematic you posted is too fuzzy to be of much good. I don't have time to try and figure out a website that's in Turkish.

Without a schematic, and without having source code to modify (not that I can program anyway), there really is not much more that I can do.

Get yourself an oscilloscope and a good LCR meter and you can play with coils all day long. The coil is your detector, all the other electronics is only the user interface. (Well, not exactly but it sounds good).

Did you program the Pic?

[Micheal]

I downloaded the Hex file onto the PIC using a pic programmer and it was very straight forward ...However I didnt write the program and I have no idea how to do so ...It was written by Baron who also designed the the detector and well done to him I say what a clever chap...As you know by now my knowledge is very limited but I really like it and I think with some tinkering help from you guys on the forum it could be a more powerful machine.
As far as coils go there have been poeple on that website that have tried many different coil parameters and different things without to much luck...I have asked him to add a timing function adjustment function and a vco because the 16f876 pic has an inbuillt tone generator to the hex and PCB but when and if it happens it will be great.Aparently there is a hex with dicrimination but that has to be paid for which is understandable.
Baron says that modifications can be done on the board side of things rather than the hex file and the hex file has nothing to do with the capabilities that can be had ...and sorry I dont think the hex can be modified and he doesnt want the hex touched in any way and we must respect his work ...but he has provided a very nice platform open to development to work with and the only thing left to do now is more tinkering