Why are commercially made detectors better than self builds?

[muddy fingers]

Anyone who has read any of my previous threads will know that I'm only a beginner with limited experience of technical matters to do with detectors so sorry if this thread again serves only to highlight my ignorance. I was reading a discussion on another forum where one of the very knowledgeable contributors stated that self build projects, no matter how skillfully they were put together, could never be as good as a commercially made detector and in all likelihood would be unused once the fun of building the project had been accomplished. I was confused reading this as I had been reading an old magazine article (1980s) which claimed that only an amateur would have the time and patience to construct a detector, particularly its coil, to the critical measurements required for maximum performance whereas a commercial manufacturer wouldn't be so bothered and would allow for tolerances of as much as 5%. I wondered why a amateur build would therefore always be inferior. Is it to do with precise machine measurements done at a factory, the quality of components, soldering standards, or the lack of sophisticated testing equipment available to the amateur? I suppose I am thinking of middle priced commercially available analogue detectors like I have myself-they all seem to have some drawbacks when being used and I was hoping eventually to be able carry out mods to them that would improve them, such as adding a meter or tone ID or making a different coil. I can understand that a commercially made detector with all the testing and research that has gone into it will be better than one made up from scratch at home with limited resources but are the amateur's efforts always inferior?

[Silver Dollar]

I believe it is possible for a home built to exceed the performance of a factory one but
there are many possible problems that might make it not as good.

A detector has to see tiny signals so the board and circuitry has to be quiet and low
noise. If you start with the exact layout you have a good start. (most have created
a new layout).

The coils are a tricky area too. If you make 100 of them you will be able to make a good
one. If you only make 1 or 2 it's hit or miss.

Most newer designs are digital and require a significant investment of time and effort to complete
a working design. We have some smart guys on here working on some great designs but all too
often when they come up with a great design they disappear and go somewhere to try to make
them commercially or sell the design so don't talk about it anymore.

Doing mods to existing ones is a good place to start but don't expect miracles as the designs
are fairly well optimized. Adding GB or changing the threshold are doable if you have a schematic
or can trace out the circuit. That's another stumbling block as modern MD's are usually surface
mount an so harder to trace out (unless you remove all components).

So a good bet is to have 1 working detector to use and a few other's to build/experiment with.

[Silver Dollar]

A couple other thoughts on this. Sometimes you build a detector not knowing what kind
it is or what kind you need. Say you make a VLF and want to use it on the beach or you
make one that is know to go super deep and have trouble in your local junk fields. So some
dissatisfaction with the finished unit could be related to how you want to use it.

Some people have followed the flow and had a 4" detector back in the 90's then got a 6"
then 8" and now need a 10" to find the stuff that is still there. So if you build the 6" and
don't find anything you might be tempted to buy a $$$ detector to be more productive.

Some people never learn to use a detector so try other ones until they get one that "works".
Nothing wrong with the other ones just they didn't take the time to learn it. It reminds me of
guitars, an expert can pick up any guitar and make it sound good, a beginner keeps trying
different ones until they find a "good" one.

I'm making a Bandito right now, vintage 1990 technology but it works in junk fields and is great
for learning on. I did find a used one and picked that up too so I could have a known good coil
and unit to test my home built on.

[Koala]

I built the IDX (same as a Classic III). Very good detector. Everything works as it's should. Works as well as most modern machines.

Modern digital processing may have improved target identification but the technology behind the detector has not changed much in since the 1990s so performance are very similar.

I use mine on a regular bases and it out preforms an original (Classic iii) which I also own. Yes the machine does take some learning but that is the same with a commercial detector.

I have not built one but the TGS in its various flavors but they are also very well developed.


The Surf and Baracuda are identical circuits to the original so if built to the same standard as the original then the performance will be identical.

Home built detectors do require some tuning to get the optimum performance. This is the same with commercial detectors. That's why some work better than others.

There is also variation due to the quality of the components used.

[muddy fingers]

Thank you very much for the very interesting replies. I think my Toltec 100 is an excellent detector but with the concentric coil it is slower on ground coverage. When in competition for finds on a well attended club site I do believe I get quicker ground coverage with a detector fitted with the DD coil as it's not so critical to overlap the sweep. Also, the 'extended discrimination' of newer models of detectors helps to find the tiny gold coins that I didn't seem to get whilst using the Eldorado and Toltec. (The disc level even at 0 was too strong for the tiny gold) The meter on the Toltec was excellent and I did read somewhere that production of the Toltec was stopped because it became too expensive to make with all its quality components. I was reading yesterday about an old meter called "Patrick Patriot". The meter alone cost $300 in it's day so again, it's use was discontinued by the manufacturers.

[sinclairuser]

its funny this thread tuning up here, a similar is on the uk detecting forum, i will repeat what i said there, the reverse engineered projects dont work the same, since componets get changed, boards get rerouted and components get mis- identified.
this introduces deviation from the original, dont get me wrong some users here build excellent detectors, but to say they are just like or as good as the original is not true.
even with the best components, and all the time in the world, you may produce a detector that works 100% but it wont be 100% original it will always be a facsimile, and that is with the collective knowledge of those here added to individual skill.
but in terms of ordinary detectorists, with minimal tools building comparable detectors, its just not possible, and building them to a proper standard that an ordinary detectorist can operate and accept in a repeatable way is so unattainable it should be discouraged.

[golfnut]

my neighbour has a Vaquero with the 8x9.5 spider and I had an hour with it on my test bed. I assumed it would be great..

I swapped to my IDx and my IDx was slightly better, using a 10" DD- Ive found a good few relics with the IDX..




Im using a hacked 250 at 16kHz with a NEL Hunter for a 14kHz Tejon, Io use it 2 clicks down on the sens and its better than the the IDx and much better than the stock 250 with its oval concentric.




Most slightly better machines, like GMP ATpro use full wave demods.

All of the entry levels like idx, basic tesoros, 250 etc use single, unbalanced detectors.. There must be a small advantage to having this.

I dont hear much system level science for why these may be better or what improvements are likely to be - however small. S