Fisher Gold Bug

[ivconic]

Funny, I never thought of my contributions to your thread as crap.
That being said, I'll leave you to your task.

But than again... it is pointless to try to do anything on these forums any more.
Good old times like 10-15 years ago will never repeat.
People changed a lot. Super sensitive on every benign word and expression you make.
Could this be due covid19 stress? And overall bad situation worldwide?
I can't tell. But obviously things has been changed dramatically in peoples minds.
I am sorry, but i don't intend to measure each word that i will post here.
I am free man. Free spirit. Benign in my acts and words. No hidden agendas.
I have huge respect to majority of people here.
But i see things are changing rapidly in pretty wrong directions.
So to spare my self on the first place and others too; from further situations like this one;
i think is better to chill out for some time and take a longer rest from forum-ing.
Cheers and Good luck!

[MartyJ1963]

@Ivconic,,,,Looking forward to seeing ths GoldBug project come to life,,,you have always amazed me ever since the day I joined the Forum in 2016,,,I always read every one of your posts and have never missed one,,I wish I had the knowledge and skill that you have in building and designing/re-designing Metal detectors as I guess would most of the members on here wish they were as good as you too. I, for one, sincerely look forward to learning from your posts, at the present, and hopefully in the future. I really admire the countless projects you have given freely here on Geotech and thank you for making this hobby the most enjoyable hobby I've ever had. Don't despair Ivconic,,,You're the best! Best regards,,,Marty.

[Nandor]

Post #25 at previous page, "ps.jpg", have you missed it?
With it i simply ended any more brainstorming around power supply.
Period.
...
But i also understand what you want to say.
I don't think that 0.5V difference (if exist in reality) will make any significant differences in detector behavior.
Remember TGSL?
It has even larger difference between the rails! Yet it worked just fine.
Comparing to that; 0.5v is nothing.
Your points are making sense to me.
But with "ps.jpg" all the doubts are ended... at least at my side.

I think I have seen this kind of powersupply at the Relic Hawk. Why not? My good old TGSL consumes only 29mA, with 2 Lipos it could last long. Maybe the oscillator would need some kind of regulation, a 6 volts regulator or so it can make 10-12 volts pp. If i remember well you said once that most commercial detectors operate between 12-16Voltspp.

[Nandor]

The CD4060-CD4013 pair looks interesting. With that divider there are many possible crystal options, its flexible.

With a frequency of 18-19kHz it would make an excellent hammered coin magnet Those medieval time coins are very tiny and slim, many of them has only 0.6 gramms.

Are there gold mines around your home Ivconic?

best regards

[ivconic]

@Ivconic,,,,Looking forward to seeing ths GoldBug project come to life,,,you have always amazed me ever since the day I joined the Forum in 2016,,,I always read every one of your posts and have never missed one,,I wish I had the knowledge and skill that you have in building and designing/re-designing Metal detectors as I guess would most of the members on here wish they were as good as you too. I, for one, sincerely look forward to learning from your posts, at the present, and hopefully in the future. I really admire the countless projects you have given freely here on Geotech and thank you for making this hobby the most enjoyable hobby I've ever had. Don't despair Ivconic,,,You're the best! Best regards,,,Marty.

Thanks! Those are indeed friendly words.
Thing is; i had several misunderstandings in last couple of weeks with few people on forum. So i kinda ask myself what's wrong?
I haven't change in last 10-15 years at all. Same spirit and same vocabulary. I notice that people became super sensitive on each word.
So is better me to shut up and avoid further disputes. It is pointless. Especially today in this situation.
...
Gold Bug is my old desire, to try to make it. But the original design (no matter how fantastic it was for its time) is not diyer-friendly at all.
Tough to obtain original crystal, transformer, some discontinued opamps and components... etc.
So it needs modifications and "modernization" to become possible to diy it.
So i started to modify it on "paper". The way i think it will work. So far, as i mentioned, i tested with real components only stage with CD4060, CD4013, TX out.
It works just fine, providing +/-90 degree phase shifted (relative to TX signal) signals for CD4053 switching. Aka "synchro-demodulator".
Most of the brainstorming will be around RX front end. How to modernize it adequately.
Author of original (Dave Johnson i assume) did it like he did, to provide specs that he could not with existing opamps at the time, i also assume.
Today should be easier, since there is wide variety of high quality opamps on the market.
So i am making step at the time with this.

[ivconic]

I think I have seen this kind of powersupply at the Relic Hawk. Why not? My good old TGSL consumes only 29mA, with 2 Lipos it could last long. Maybe the oscillator would need some kind of regulation, a 6 volts regulator or so it can make 10-12 volts pp. If i remember well you said once that most commercial detectors operate between 12-16Voltspp.

Similar, not the same.
Actually its Davor's "quilt" that i decided to use power supply which schematic i posted last here.
For years i've been listening Davor's arguments and he is completely right (as usual).
If you want best possible S/N ratio in power rails; avoid any kind of regulators, use power directly from batteries.
With higher current capacity at batteries (and bunch of caps in between); it would not be a problem if voltage drops slowly withing 0.5 volts in time.
In the past it was hard, today is easy, LiPos are just perfect for this role.
If rails are kept within 3.7V to 3.9V most of the time; everything will work just fine.
...
This also helps to understand why author of original decided to do the power supply the way is done.

[ivconic]

...With a frequency of 18-19kHz it would make an excellent hammered coin magnet Those medieval time coins are very tiny and slim, many of them has only 0.6 gramms.
Are there gold mines around your home Ivconic?...

No gold mines here, closer than 100km away.
Nor i am interested in gold. But you already guessed it; i would like to see how it will perform on tiny coins and particles.
Another more serious reason is that i see again rise of interest for detecting needles and arrow pins made from non magnetic metals and alloys.
That problem is not solved yet in diyers world. We made lot of various diys so far, yet we didn't make such detector.
Lobo is made by diyers and is probably close to what we want. I haven't tried it. I picked Gold Bug instead, looks more interesting to me.

[MartyJ1963]

Thanks Ivconic,,,Can't wait to learn more from your vast knowledge and perserverence,,you truly are 'one of a kind'. Regards, Marty.

[liekwang]

I am "contemplating" more wider options now.
[ATTACH]53397[/ATTACH]

Mr. Invonic, if you wish, please show the circuit section for the audio gold bug separately from the scheme you gave. I like the audio gold bug sound.

[ivconic]

Mr. Invonic, if you wish, please show the circuit section for the audio gold bug separately from the scheme you gave. I like the audio gold bug sound.

If you can't do it by yourself; than separate circuit for generating audio will not help you at all.
You must understand schematic and be able to analyze at least main blocks on it.
Starting from "Svirajka" note on schematic, to the left where speaker is; that's the audio.
But audio will depend also on the rest of circuit, the signal that comes from channels and switch on the audio stage.
I think you will have more luck with 1265 audio instead. Similar circuit.
Search old topics for 1265 or even better for SMW2.
I used 1265 audio for SMW2.
But if you are not able to analyze and understand it by yourself; than you'll just waste your time.
Instead of asking too much and constant questions like that one, on many other topics too; READ OLD topics!
Look up for 1265 topics, go to the first pages at all 1265 topics and READ from the beginning all posts.
Same with SMW2. READ!
That's how you will learn the best, on your own.
Asking simpleminded questions all over the forums will not provide you any valuable knowledge.
Take this as friendly advice.

[ivconic]

Thanks Ivconic,,,Can't wait to learn more from your vast knowledge and perserverence,,you truly are 'one of a kind'. Regards, Marty.

Right now i am stuck at most painful stage of the process; drawing pcb!
Seems i am totally out of shape for this to do it right.
I already have 2 attempts, two unfinished drawings, that i gave up already from.
Lot of pain at this stage!
Because i am trying to arrange it nice, logical, "flowing" and on rather smaller pcb area.

[Nandor]

I know an old guy here in my city, he's making the pcb's on paper without any program. I was amazed how he knows every ic's pin he uses. For me power lines make the most headache, I always forgot them
Signal lines are also sensitive, well its not work, making pcb's its art work, so think about it as a piece of art Im very curious about your results.
Nice to see you making this project. Last year maybe, you told me you quit making detectors i was sad to hear that, and now you are making them again!

Good luck man!

[Nandor]

What about the coils, do you have an original coil for it?

[liekwang]

If you can't do it by yourself; than separate circuit for generating audio will not help you at all.
You must understand schematic and be able to analyze at least main blocks on it.
Starting from "Svirajka" note on schematic, to the left where speaker is; that's the audio.
But audio will depend also on the rest of circuit, the signal that comes from channels and switch on the audio stage.
I think you will have more luck with 1265 audio instead. Similar circuit.
Search old topics for 1265 or even better for SMW2.
I used 1265 audio for SMW2.
But if you are not able to analyze and understand it by yourself; than you'll just waste your time.
Instead of asking too much and constant questions like that one, on many other topics too; READ OLD topics!
Look up for 1265 topics, go to the first pages at all 1265 topics and READ from the beginning all posts.
Same with SMW2. READ!
That's how you will learn the best, on your own.
Asking simpleminded questions all over the forums will not provide you any valuable knowledge.
Take this as friendly advice.

ok I understand from the last schema you published the same as smw audio,

[gurdal]

ivconic is one of the fast-growing masters.
God give you a clear mind