Concentric coil for IDX

[nalag46]

Coil help

Hi Don,
Did you receive the email I sent you 12th. November to your aol.com address?
I was requesting your knowledgeable help with a missing coil on my Whites Treasuremaster VLF? I am attaching copy of message and any info. you can pass on
would be most appreciated. Tony

[golfnut]

Just chipping in before Don .. clearly the Tx coil is missing. The photo doesn't have enough detail to see if the buck is still there ? I suspect it is. The Rx coil is there and the Tx and Rx coils both appear to have the tuning caps in there. The loose bundle in the centre is the operator adding or removing a couple of turns for nulling/phasing. S

[nalag46]

The loose bundle in the middle appears to be two or three turns for the nulling. This is a run of cable connected at the end of the RX coil.
It I the TX coil winding details I need.

[mohandes]

Yes, you must add capacitors to allow resonance. You can then adjust frequency by adding a turn or two. I can't say why a particular coil cannot be nulled. I can only document what I did to put a concentric together. I would feel better if my results could be reproduced.
Hopefully some of the videos I posted on youtube are proof that the recipe in the .pdf works...

ok
but i make dd coil like pdf nd work!!
i just get 7 volt p-p fpr TX coil (when connect to BX coil )???why ??

[ashefr10]

it is true that the simplest system is the double D coil, the galley is concentric with the coil B balancing.