Whites TDI SL Coil Differences

[Roger]

Weight discrepancy?

I have two 12” Whites TDI coils that each accompanied a TDI SL.

The one without label has a cable length of 176cm and weighs 495gm.

The one with label has a cable length of 133cm and weighs 544gm.

Neither are wearing a coil protector. They are the same thickness and diameter.

Why would the coil with longer cable weigh less than the one with shorter cable? Both cables have Whites Electronics printed on them and are of the same diameter and feel.

Why the differences?

Regards,

Rog

[RickUK]

Possibly and this is a total shot in the dark but one could be a Mono coil which of course have less copper winding so in theory should be lighter,and the other is probably a Dual field coil with copper winding on the small coil section......of course i could be wrong and is purely just a guess.

[Roger]

Well my goodness Rick, I had the same suspicion. Unfortunately I have no technical knowledge whatsover and cannot even solder.  The coils would benefit from being tested with some apparatus maybe.  I did look at pictures of the coil made for the Oz TDI which is slightly different to a Dual Field housing.  But these two housings are identical, so that would rule out one being an Oz coil.

Regards,

Rog

[Ridge Runner]

To check to see what you have use a Pinpointer and check the center coil to see if it has a winding in it . If so then that one is a dual field coil.

 Chuck 

[Roger]

Hello all, and thank you Chuck, mystery solved partly.  The coil with label has two windings, inner and outer, the one without label has only the outer winding.

The background to this is that I bought a buff coloured TDI SL plus coil from Centreville Electronics.  On its second use it made a loud noise and stopped working.  I sent it and the coil back to Centreville.  I had taken a picture of the sticker inside prior to sending them back.

When the unit and a coil was returned I was told that there had been a 'swap out' which I took to be either a full rebuild, partial rebuild or a complete sawp of the buff box and contents. Unfortunately I do not recall what the original coil looked like and whether the coil was swapped or not.  I did ask, but no reply.  Perhaps someone would be able to decipher/interpret the replacements label?

I have just done a quick air test and the non label coil does work (1st time connected to the unit since replacement as I use the labeled one).  The coil that was returned was without a coil cover/protector.

That's as much information as I think I have; so what is the non label coil?

Regards,

Rog

1st picture is the unit returned to Centrevill.

2nd picture is on the returned unit to me.

 

[Ridge Runner]

If you got a winding on both then you have a dual field and that’s one great coil just because you have a big coil plus a small at the same time. You not having to change from one coil to another.

 The only trouble as we get older that coil gets heavy.

[Jim in Idaho]

Yup, Chuck, I hated that coil. IMHO, the Miner John 8 x 12 is lighter, more maneuverable, and more sensitive.

Jim

[Ridge Runner]

Jim

Coils are like people in when they die out we look back saying it are they were great.

 I had some of the coils and I really liked with others I could do without.

 People are the important ones and only one of a kind.

 Chuck 

[Roger]

Any ideas then as to what the single winding coil is?

Regards,

Rog

[Ridge Runner]

Roger  

 it’s just no more than a small coil working in harmony with the big outside coil, Just more sensitive to small targets than the outside coil That’s where they came up with the wording Dual Field coil.

 Chuck