choice for a 18 khz

[Qiaozhi]

false. I do not speak of simultaneous multi frequency. but only to switch from 6.6 to 18 khz .I will follow qiaozhi's advice. for info and this since the since this thread i have already tested idx 17.5 khz .. and it works ... thank you.

The only issue you may encounter is with the ground balance and discrimination settings. But I guess you've already found that's ok?
Often trying to build a VLF circuit with a homemade coil can be a real "mal de tête". That's why we always advise people to use a commercial coil as a starting point.

[lamoiz]

Also, there are sometimes problems in translation.
---
problems are not in translation. problems are there is not possibility to do multifrequency detector from IDX.
IDX is ended product and very good for start of electronics learning and good learning platform.
but... you can not to do an elephant from a fly.

false. I do not speak of simultaneous multi frequency. but only to switch from 6.6 to 18 khz .I will follow qiaozhi's advice. for info and this since the since this thread i have already tested idx 17.5 khz .. and it works ... thank you.

[kt315]

Also, there are sometimes problems in translation.
---
problems are not in translation. problems are there is not possibility to do multifrequency detector from IDX.
IDX is ended product and very good for start of electronics learning and good learning platform.
but... you can not to do an elephant from a fly.

[lamoiz]

I think there is some confusion here. When we talk about multi-frequency, thus usually refers to multiple frequencies being transmitted at once. What you're referring to appears to be the ability to switch a coil between two different transmit frequencies. If that's what you're planning to do, then you should balance your coil at the highest frequency. The simplest method of changing frequency would be to use small PCB relays to switch in different capacitor values for TX and RX.

By the way, most people here are hobbyists with varying levels of knowledge. Also, there are sometimes problems in translation.

A big thank you qiaochi. yes I think there is a lot of translation and understanding problem here .... Thank you for your technical answer. I'm going to balance my coil at 18 khz ... I wanted to do the opposite .... so I'll test it tomorrow. why do you think that all the others are fools ...... thanks to you

[Qiaozhi]

Yes . but it's not my queston..I do not want to make a multifrequency.I just want an explanation of the arrangement of coils in a multi-frequency head ...
I will tune and position the coils with the capacity for 6.6khz..after with a switch 2 positions 4 inverters I want to switch on the tuning values for 18 khz ... the difference between the two frequencies is may be too large. .. I do not know if the electronics of the IDX will do the job. This will be done in a few days.

I think there is some confusion here. When we talk about multi-frequency, thus usually refers to multiple frequencies being transmitted at once. What you're referring to appears to be the ability to switch a coil between two different transmit frequencies. If that's what you're planning to do, then you should balance your coil at the highest frequency. The simplest method of changing frequency would be to use small PCB relays to switch in different capacitor values for TX and RX.

By the way, most people here are hobbyists with varying levels of knowledge. Also, there are sometimes problems in translation.

[lamoiz]

I must conclude after this post that my ideas are totally bad .... It is true that on this forum, there are only engineers in electronics.I am actually engineer .... but acoustics .... Preston .. if you give money .. you have your diplomas .... ok geotech forum should be another name then ..... geotech engineer forum ...... this is a proposal. I'll put my oscilloscope in the trash and resume gardening. sometimes we can discover small gold with a rake. You did not have your pedagogical diploma.

[kt315]

this pcb from coil in my hand. with the chipo at it.

[kt315]

ok. why only coil? what you will do with all phase tunings? why i do not think whites electronics
engineers' stuff are so idiotics that are not able to add multi freq in IDX while you infer that is?

is your basic knowledge an electronics degree of Preston university?

if they could do, they would have done it necessarily. its main rule.

[lamoiz]

Yes . but it's not my queston..
---vs
How do the manufacturers for multi frequency coils ..? 5 ...... to .... 70khz
----

sorry, but it is your question.

this is not my original question ..in the french language have sometimes used a question ..to answer another question ....
but thanks for the explanations.
the initial question was: can we replace a switch 2 positions 4 inverters by an integrated circuit..if yes which ..? and this simply to avoid taking up too much space in the control box ..... the second question was the IDX will it do the job if the chord of the coil goes from 6.6 to 18 khz ...

[kt315]

Yes . but it's not my queston..
---vs
How do the manufacturers for multi frequency coils ..? 5 ...... to .... 70khz
----

sorry, but it is your question.

[kt315]

I just want an explanation of the arrangement of coils in a multi-frequency head ...
----
arrangment of coils is special microchip inside with interface to main block/main micro.
main micro asks coil micro and coil micro answers to main micro about on what frequency to work.
then main micro turns up the TX frequency on frequency of the coil.

[lamoiz]

How do the manufacturers for multi frequency coils ..? 5 ...... to .... 70khz
---

manufacturers do not share the information in forums. you mean only microchip based schematics matter, you have not possibility
to do multi in an analog schematic.
if you need multi so try to do QUAZAR ARM.

Yes . but it's not my queston..I do not want to make a multifrequency.I just want an explanation of the arrangement of coils in a multi-frequency head ...
I will tune and position the coils with the capacity for 6.6khz..after with a switch 2 positions 4 inverters I want to switch on the tuning values for 18 khz ... the difference between the two frequencies is may be too large. .. I do not know if the electronics of the IDX will do the job. This will be done in a few days.

[kt315]

How do the manufacturers for multi frequency coils ..? 5 ...... to .... 70khz
---

manufacturers do not share the information in forums. you mean only microchip based schematics matter, you have not possibility
to do multi in an analog schematic.
if you need multi so try to do QUAZAR ARM.

[lamoiz]

Hello,
the balance of the coils rx and tx is independent of the capacitance values .. no? in the Tesoro coils there are no capacitors. But they can work from 10 to 12 or 14 to 18 khz ... How do the manufacturers for multi frequency coils ..? 5 ...... to .... 70khz ... it is impossible to position the windings in real time .... so maybe a guru of the site wants to explain that ...

[blobber]

Here is a good example, that it is possible to use one coil, for different frequencys in VLF detector. Fortuna M with 4, 7 and 12kHz.

https://youtu.be/pvHiykVof2I