Matchless metal detector

[Davor]

Here comes the mixer. It might be confusing at start, but it is not, I promise.
I need sine to work with notch, so I have to mix sine wave obtained at the tank. I also want to avoid mixing analogue signal twice, so instead I'm mixing two digital signals, and obtain PWM product. It has no low frequency components, so it does not impair resonance of a sine wave tank (I guess).
The resultant signal is 1Vpp pretty pure sine, so notch will work. I put some amplification here, however, It is just because I wish it to remain a seventh grade project. It can also be tumbled around and use opamps.

Simulation is prepared for 7 and 9V supply.

Only one part is missing, 555 oscillators.

[WM6]

Nice Davor.

What is your complete idea? Can you post something like a bock scheme of your design?

[Davor]

Only oscillators are missing, but I'm sick, and not up to completing it at the moment.
A whole idea is combining two tank oscillators, much like the matchless, that are producing frequencies far apart to completely avoid synchronisation problem. A third RC oscillator is used to reduce the beat frequency into a more sensible range ~400Hz. Mixing is performed in a way that the resultant 400Hz tone is a pure sine, and it can be notched out. So, in absence of events you enjoy silence, and in case there is a metal it produces tone. Easy.

Traditional BFOs use one tank and a local oscillator. Matchless showed that it can be done otherwise, and I like the concept.

[TH Jim]

Hi folks,

I havent looked at the schematic of the matchless for years (I'm not a fan of scarborough's designs, he reinvents the wheel and claims its something new and novell like his CCO or BB design which are just armstrong oscillators that can be found in almost any cheap stud/nail detector, but anyway i digress!)

If my memory serves me correctly the matchless is an IB design, right?

Regards, Jim.

[wallker]

If my memory serves me correctly the matchless is an IB design, right?

Regards, Jim.

Your memory serves you good, it's IB design.
Regards.

[der_fisherman]

Hi folks,

I havent looked at the schematic of the matchless for years (I'm not a fan of scarborough's designs, he reinvents the wheel and claims its something new and novell like his CCO or BB design which are just armstrong oscillators that can be found in almost any cheap stud/nail detector, but anyway i digress!)

If my memory serves me correctly the matchless is an IB design, right?

Regards, Jim.

For someone who according to himself has not even looked at the circuit of the Matchless, I find your comments to be very much out of order with regard to the Reverend Scarborough.

In fact your comments come over as being from someone who is green with envy to my mind.....

He has been published in more magazines than I can name around the world and of the articles that I have read, he has been very highly complimented on his "refreshingly" new ideas on an old (MDs) subject from other experts that write for magazines as well as the readers......thats enough for me.

Where have you been published? Countries and the magazines/publications please, with dates.....I have not been published with any original (or not) designs myself.....

There is nothing really new in this world, but the Rev appears to be as near as you can get to an innovator in many areas nowadays........he also comes across as a pleasant person both on his website and in the publicized articles that I have read of his....

My point being that if you cannot say something nice about anyone, then just say nothing. Understood?

Have a great day anyway.....

regards
Andy

[TH Jim]

Der Fisherman


You are incorrect. If you read my post properly you would see that I said I have previously looked at the matchless circuit but not for a long time.

I have had several articles published in Britains leading metal detecting magazine "Treasure Hunting". The first being about my own IB design!!! I'll have to look up the dates if you would really like me to?

Same question right back at you matey - lets see some of your work then???

I did not critcise scarborough personally but his published work - i did not realize that there were opinion police at work gaurding the forum

I suggest you take another look at his claims then go and learn something about metal detector circuits - then we can debate just how "new" and "inventive" the CCO circuit really is.

And NO - This happens to be a civilized, free, democratic world my friend and I will say what I please about things I do not agree with - Understood!

Have a nice day.

[der_fisherman]

Der Fisherman


You are incorrect. If you read my post properly you would see that I said I have previously looked at the matchless circuit but not for a long time.

I have had several articles published in Britains leading metal detecting magazine "Treasure Hunting". The first being about my own IB design!!! I'll have to look up the dates if you would really like me to?

Same question right back at you matey - lets see some of your work then???

I did not critcise scarborough personally but his published work - i did not realize that there were opinion police at work gaurding the forum

I suggest you take another look at his claims then go and learn something about metal detector circuits - then we can debate just how "new" and "inventive" the CCO circuit really is.

And NO - This happens to be a civilized, free, democratic world my friend and I will say what I please about things I do not agree with - Understood!

Have a nice day.

As I mentioned before, I have not published, I am not a design engineer. This just demonstrates that you did not understand the post fully and you seemed to have missed the point completely, I will remind you:-

"If you cannot be pleasant, don't post"

Have you understood now?

Its not "opinion" Police, its manners, or your lack of them!!!

Have a great day,

Andy

PS Can you post a copy of the IB design you made on Geotech as I live in Germany and do not have access to the magazine you mentioned, or have you already posted it here for us?
Thanks in advance.

[TH Jim]

Andy,

I have not seen any of your recent posts that state you have not been published - can you quote or provide a link to show us where you said this please?

Do you understand the concept of freedom of speech? This forum is for people to debate the merits or shortcomings of metal detector designs, it is not a mutual appreciation club. It is by reasonable critisim and peer review that we make progress in science. My comments about the matchless were not at all offensive, I did not slight the authors character, I merely voiced my doubts over the claims he has made about his work.

When I was a newbie I read some of Rev Scarboroughs articles and took them at face value and built some of his circuits. Now that I have a bit more experience I can see that i was wasting my time, and as such I think it only fair to warn other newbies that they may be about to make the same mistake.

It is you that has been unpleasant in the tone with which you have attempted to reprimand my post. Putting the word "understood" at the end of a sentance is the type of authoritative and contemptuous language I would expect to hear from a teacher speaking to a naughty child. How dare you. It is you who lacks manners.

As I said this forum is for discussing metal detectors - it is not the place for airing personal disagreements. If you would like to continue this ridiculous argument then why not order a back issue of my articles from GreenLight publishing and use my email address which is printed at the end of each article to contact me and give your opinion on what i have written - it is your right to do so, i will not try to stop you or criticise you for doing so.

Treasure Hunting:
October 2008, Page 36, "A phoenix rises", By Geotech Jim.
October 2009, Page 44, "Something to read on the beach", By Geotech Jim.

You can order them hear,
http://shop1.actinicexpress.co.uk/sh...b37531b2d1ae68

I look forward to your review.

Regards, Jim

[Davor]

And so it goes on and on without any resolve. Too bad. It will not make rev Scarborough's circuits any more elaborate

On the other hand, given a choice between a matchless and a TGSL as a weekend project, well ... (of course, if you have a pair of crystal earphones at hand).

[der_fisherman]

Regarding good manners when posting on Geotech.

I have not seen any of your recent posts that state you have not been published - can you quote or provide a link to show us where you said this please?

If you had been paying more attention, rather than getting hot under the collar for no reason when requested to curb your manner, you would have seen that in my first post to you!!! Try reading slower, you may get the gist better!!!

Furthermore it is probably unlikely that I will ever publish anything about metal detecting as I am not so full of myself that I feel the need to do so.....also the fact that I am more "au fait" with digital electronics than analog is a further slight brake in that direction I have to admit. Sadly, it would appear that your published articles have "gone to your head", making you far "better" than all of us here in your eyes? As J.C. would have put it Veni, Vidi, Vici maybe?

As I said this forum is for discussing metal detectors - it is not the place for airing personal disagreements. If you would like to continue this ridiculous argument........

Well said, so why did you attack the Rev and his understanding and usage of electronics in the way you did.....? It would appear to go against your own beliefs, it certainly went against mine!!!

As I have said before, I do not see it as an argument, its a difference of opinion about good manners, nothing more nothing less to my mind.....your opinion may differ.

I am stating obvious facts from your first and subsequent emails, my main point is still "if you cannot say anything nice about him then simply leave it!" and you are trying to call it an argument!! Get a life!!

An argument demands aggression from two people, your aggression is almost enough for two I have to admit, but I was simply pointing out what was apparent to me was simply a failure in good manners.....

Thanks for the references of your two publicized articles but I am unwilling to start buying magazines from abroad, to maybe end up in regretting the cost involved versus the value of the contents, me being a pensioner and having a limited "Hobby" income.

I had hoped that it would be available somewhere on the web to find and read or even on Geotech where many such fine articles and info's are often published/available, as well as infos unavailable anywhere else. So I will be unable to "rate" your knowledge....how sad for us both!!

Many other designers and authors have published online for almost anyone to read, the Reverend Scarborough articles for example are easily found on dozens of web sites. There does not appear to be a downside for him at least in that.....

I am calling a halt to this misunderstanding here and now and I will not be bothering to reply to any further contact/argument from you as I can see that you are only convinced of the validity of your own opinions and cannot listen to anyone else in this world, who is maybe of a different viewpoint, also I have far better things to do with the last few years of my life than to talk (sorry "argue") with you, scratching my rear end for example comes to mind!! Though its not required that often and I get it done quite quickly!!!

Bye. Therefore please feel free to carry on as you have done already, but without me being in any way shape or form involved!

Regards

Andy

A dyed in the wool Reverend Scarborough (and those others who publish freely on the web) Fan!!

[TH Jim]

I have not been published with any original (or not) designs myself.....

I stand corrected! Yes I should read slower

[TH Jim]

You are absolutely right that I've got hot under the collar due to direct provocation. I do not see why i should have to put up with public deformation of character by a stroppy pensioner. All I said was that I am not a fan of TS's work and that I do not agree with his claims. That is not being rude or bad mannered.

You on the other hand spoke down to me, using contemptuous tone and unfounded assumptions like "green with envy" - well I think we've dispelled that one now But you continue with "gone to your head" and "better" than all of us here. The fact is that anyone with half a brain can write an article for a magazine - it's really not that much of an achievement. To be honest the article and the detector design were not even very good as it was my first foray into both and there are much better here on geotech. I am a humble man, I have never before mentioned my published work on this forum until you asked me if i had any and to provide details - so that is what i did. It seems you were attempting to elevate TS to some unquestionably higher status than the rest of us whilst relegating me to the staus of ordinary. Well that little plan kind of back fired on you didn't it

I in fact will readily admit that their are far better brains on this forum than I, who are far more knowledgeable than I, and I enjoy their company and their helpfull critisism when I get things wrong.

ar·gu·ment

   /ˈɑrgyəmənt/ Show Spelled[ahr-gyuh-muhnt] Show IPA
noun 1. an oral disagreement; verbal opposition; contention; altercation: a violent argument.

2. a discussion involving differing points of view; debate: They were deeply involved in an argument about inflation.

3. a process of reasoning; series of reasons: I couldn't follow his argument.

4. a statement, reason, or fact for or against a point: This is a strong argument in favor of her theory.

5. an address or composition intended to convince or persuade; persuasive discourse


Aggression is not a prerequisite for an argument, and I have not shown any, I have merely defended my opinion against your dictatorial demands. I will not be censored from giving my polite opinion by dictators like you. If a person puts their work into the public domain then they must be ready to accept critisim, this applies to me, you and to the RevTS.

I commented on TS's work because I think his claims are incorrect. If anyone would like to correct me on the validity of his claims then please feel free.

I can accuse you of exactly the same - you have made no attempt to give any ground, you have not mentioned my point about the rudeness of your demands - Understood!

I'm glad to hear that you will not be replying as I am sick of having to come here and defend myself agianst your baseless argument.

Being a young man I am very busy with things like bathing and getting out of my seat to go to the lavatory - try that next time you feel an itch in your rear end!

Now let me hypothesise:

I think the reason you launched your attack on me is not because of what I said but because of who I said it about? You are a self confessed fan of TS, I wonder would you have got so upset if it was someone elses work and i made exactly the same comment about it?

Goodbye Der

[der_fisherman]

Answering a young and in experienced person....

You are absolutely right that I've got hot under the collar due to direct provocation. I do not see why i should have to put up with public deformation of character by a stroppy pensioner. All I said was that I am not a fan of TS's work and that I do not agree with his claims. That is not being rude or bad mannered.

Sorry, you are 100% wrong, it is rude and ill mannered. It is not the way we work on Geotech.

You on the other hand spoke down to me, using contemptuous tone and unfounded assumptions like "green with envy" - well I think we've dispelled that one now But you continue with "gone to your head" and "better" than all of us here. The fact is that anyone with half a brain can write an article for a magazine - it's really not that much of an achievement. To be honest the article and the detector design were not even very good as it was my first foray into both and there are much better here on geotech. I am a humble man, I have never before mentioned my published work on this forum until you asked me if i had any and to provide details - so that is what i did. It seems you were attempting to elevate TS to some unquestionably higher status than the rest of us whilst relegating me to the staus of ordinary. Well that little plan kind of back fired on you didn't it

Totally wrong, you FEEL that I spoke down to you, read it slowly and you will see that was not what I was trying to do, I was simply telling you that it was not good and to leave it.

Also you mentioned in the same post where you criticized the Reverend Scarborough that you had been published, seemingly as a reason that enabled you to say such things. That was the reason I got upset!!!! Without that I probably would have simply ignored your post completely!!Thats why I said "green with envy" as I could not think of another reason for your attack.....
TS will be elevated by the number of people who find him lacking, only one as of now!! Guess who that was?

I in fact will readily admit that their are far better brains on this forum than I, who are far more knowledgeable than I, and I enjoy their company and their helpfull critisism when I get things wrong.

Now I do agree with you there!!!! Their brains are FAR better!!!Their manners also, which is more important!

ar·gu·ment

   /ˈɑrgyəmənt/ Show Spelled[ahr-gyuh-muhnt] Show IPA
noun 1. an oral disagreement; verbal opposition; contention; altercation: a violent argument.

2. a discussion involving differing points of view; debate: They were deeply involved in an argument about inflation.

3. a process of reasoning; series of reasons: I couldn't follow his argument.

4. a statement, reason, or fact for or against a point: This is a strong argument in favor of her theory.

5. an address or composition intended to convince or persuade; persuasive discourse


Aggression is not a prerequisite for an argument, and I have not shown any, I have merely defended my opinion against your dictatorial demands. I will not be censored from giving my polite opinion by dictators like you. If a person puts their work into the public domain then they must be ready to accept critisim, this applies to me, you and to the RevTS.

I commented on TS's work because I think his claims are incorrect. If anyone would like to correct me on the validity of his claims then please feel free.

I can accuse you of exactly the same - you have made no attempt to give any ground, you have not mentioned my point about the rudeness of your demands - Understood!

You really do show no remorse, no understanding and no idea why you are wrong, wrong, wrong!!!! You say that "you THINK" he is incorrect......not a strong reason buddy!! I really do feel that you are right in one sense though, you simply cannot believe or understand that anyone finds your attitude unacceptable......but I am sure I am not alone in failing to understand your point of view i9n this area.........

I'm glad to hear that you will not be replying as I am sick of having to come here and defend myself agianst your baseless argument.

Wrong, I changed my mind simply because you still demonstrate a complete lack of simple basic human understanding.....even a young peron generally demonstrates more feeling in such areas.....

eing a young man I am very busy with things like bathing and getting out of my seat to go to the lavatory - try that next time you feel an itch in your rear end!

This demonstrates your immature stupidity simply in a single sentence!!!!!! or do you mean that sometimes you remain in your seat to go to the toilet? (my daughter did this before she was potty trained.....up till she was about 22 months......

Now let me hypothesise:

Nothing new here buddy!!!

I think the reason you launched your attack on me is not because of what I said but because of who I said it about? You are a self confessed fan of TS, I wonder would you have got so upset if it was someone elses work and i made exactly the same comment about it?

Goodbye Der

You would not have attacked anyone who had not been published many times as you were trying to put yourself on a higher plane than a respected and strongly religious person.....you should have picked someone who was completely unknown or un-respected.......big error buddy.

Also I am changing my mind in not replying....have you noticed? There are no rules to stop me on that point as far as I am aware...

I will give you a really worthwhile tip, think LONG and HARD before replying further, make your words count, make the logical reasoning sensible. Up to now you have not achieved that.......

A simple apology to the Reverend Scarborough would be the polite and proper way to end this.

I have a feeling (please, please prove me wrong!) that you are also neither polite or proper in your life offline, simply put you are just young and obviously s****d.......but I am fully prepared to be wrong on all accounts, something that you are not it would seem, but are you prepared to prove the opposite and accept that you are wrong?

I bet on NO!!! Am I right or wrong? The future will show.....or I could say "We will see".

I wonder if you really want some more aggravation here? I somehow feel that the answer will probably be YES (DUUUHHH!)

So do what you need to do, the same way that I will.......but if you decide not to reply, neither will I.

Have a great day anyway as I feel that all of this is still educating you a little bit better in the way life REALLY is and what manners really are.......I am fully prepared either way.

It now rests with you personally..

Andy

PS I am actually enjoying this duck shoot, the targets are mostly easy to hit. What is strange is that the targets are patently not realising this!!

[Qiaozhi]

OK guys, I think this has gone far enough.
Please read the Basic Rules of the Forums ->
http://www.geotech1.com/forums/showthread.php?t=10526

In particular, the part where it says:
"Criticism should be relevant and constructive. If you disagree with something, state your case, and move on."

It's time to move on.