coil to coil match

[Mark-VA]

Using coils from other companies.

My thinking which might be wrong

If the impendance (ohm readings) of both coils seem to be the same or close then, other factors will need to be considered correct?
Or are they compatible?
Example: inductance and capacitance which will define the reactance of the coil circuit, correct?


Thanks in advance

Mark

[Davor]

Also the Q factor that is related to coil wire thickness. If Q is too low (coil resistance is too high) some detectors will not be able to start oscillation.

It is only a bit different with PI machines.

[satdaveuk]

Using coils from other companies.

My thinking which might be wrong

If the impendance (ohm readings) of both coils seem to be the same or close then, other factors will need to be considered correct?
Or are they compatible?
Example: inductance and capacitance which will define the reactance of the coil circuit, correct?


Thanks in advance

Mark

Hi Mark
Sorry for been a bit late replying to this but been busy
Duplicating MD coils can be fairly straight forward providing they are a unturned type format which means no components apart from coil wire , IE like the Whites DFX, Prizm, or the TGS etc and numbrious others.
What you need is the coil checker which you can build,( construction details are in this forum to get the coil oscillating ), a frequency counter, scope, and a accurate LCR meter .
Once you work out your pin connections read the resistance/inductance with your LCR and multimeter then connect your original coil to the coil checker and frequency counter which you will then get accurate frequency of your coil excluding CX .
Then its a question of duplicating.
When nulling the coils use coil checker/Scope again duplicating readings from original
Have done a few with very good results.
Regards

[Mark-VA]

Thanks for the reply. By what you are saying, duplicating a coil on the new CTX would be a huge undertaking.

[satdaveuk]

Hi Mark
I don't know anything about the new CTX
There are certain coils like some of the later ML where by they have built most of the TX side of things into the coils where by if you take readings on two of the pins your into Megohms in fact some people have presumed they have faulty coils.
Instances like that unless you have circuit diagram and part numbers your pretty well knacked.
However theres still lots of coils out there old and modern that can be duplicated with time and effort with the kit I stated previously, and that very same equipment tells you if its doable or not.
First thing I would do with your coil is check continuity for pin out connections, secondly check TX/RX resistance/inductance, then connect it to the coil oscillator/checker and frequency meter which will give you a free running frequency, then by connecting your scope you will see your nulling point, for instance TGSL was 5mvp-p if I remember correctly
If you can get all that information as Ive stated then go to the coil calculator which is here and work out your wire size, amount of windings etc.
Its always allot easer to duplicate a coil than building from scratch because you have a working reference to build on.
I learned that in the early days with Ivonics TGSL project which is Induction balance format, I wasted so much time and money building coils for it, and in them days if you look through the thread the TGSL was in its infancy and problems needed ironing out, but we got there with team effort.
Anyway bought a manufacture coil for it, tweeked the TX/RX CXs and it worked a dream.
I then duplicated and nulled coils with the procedure thats stated and everything worked fine, made others for different brands and same results, and now we have the shielding sorted out its gone from good to great.