CS3MX Elliptical coil build?

[morning wood]

The CS220 is also a non-motion detector.

Have you looked the TGSL design? PCBs are available from Silverdog.
http://www.geotech1.com/forums/showthread.php?t=15710

Thanks looks ideal . Just ordered the PCB and most of the other bits I've already got. I'm looking forward to having a play

[Qiaozhi]

Further to this, a quick measurement shows dc supply lines on the coil lead so there must be some active electronics in the search head. I think I'll scrub that idea for now and perhaps build a small specific IB machine or similar. Any recomendations??

The CS220 is also a non-motion detector.

Have you looked the TGSL design? PCBs are available from Silverdog.
http://www.geotech1.com/forums/showthread.php?t=15710

[morning wood]

Further to this, a quick measurement shows dc supply lines on the coil lead so there must be some active electronics in the search head. I think I'll scrub that idea for now and perhaps build a small specific IB machine or similar. Any recomendations??

[morning wood]

I'm sure the 1220XD is a non-motion machine so I guess it might be quite different

[Qiaozhi]

I've got a 10 inch coil from a 1220XD open at the moment. My friend ripped it open before he gave it to me and some of the enamel wires have detached from the small board inside. The board has (from memory as i'm not at home now) 2 tuning pots and 2 caps. Think the cscopes use a hartley oscillator.

Is it an Isocon coil? I think this is an important point.

[TH Jim]

I've got a 10 inch coil from a 1220XD open at the moment. My friend ripped it open before he gave it to me and some of the enamel wires have detached from the small board inside. The board has (from memory as i'm not at home now) 2 tuning pots and 2 caps. Think the cscopes use a hartley oscillator.

[Qiaozhi]

Ah that's interesting as I had a very quick probe with the scope lastnight and couldn't actually find the TX signal on any of the coil connections, although loop coupling the scope probe to the search head the 17kHz signal was definitely present. I had a pobe with the multimeter and all the coil connections seemed open-circuit but I couldn't be sure I tried all permutations. I did then start to wonder if they were ac coupled for some reason. I'll have another look later to see if one of the coil connections is carrying dc as that'll be a sure sign that some electronics are present in the search head I guess.

Thanks for the input

That's exactly what I found with the CS220. There were 3 wires: green/screen (0V), red (RX I/P), and black (-6V).

[morning wood]

An isocon coil from a CS220, that I examined, had the TX circuit inside the search head. I don't know if this is a common feature for CScope, so it might be worth checking the continuity on the coil winding before proceeding.

Ah that's interesting as I had a very quick probe with the scope lastnight and couldn't actually find the TX signal on any of the coil connections, although loop coupling the scope probe to the search head the 17kHz signal was definitely present. I had a pobe with the multimeter and all the coil connections seemed open-circuit but I couldn't be sure I tried all permutations. I did then start to wonder if they were ac coupled for some reason. I'll have another look later to see if one of the coil connections is carrying dc as that'll be a sure sign that some electronics are present in the search head I guess.

Thanks for the input

[Qiaozhi]

Hi all, new here....

I've a cscope cs3mx and looking to build a small elliptical coil, mainly for getting in the nooks and crannies around the trees up the woods. The stock coil is described as 'isocon' and the search head resembles a polo so I'm assuming it's concentric design. I've not done any probing around yet but if anyone has any experience of this machine or similar it would be great to hear from you.

I'm an electronics engineer as a job, mainly microwave/rf so know problem with some of the skills required.

Cheers,

Paul.

An isocon coil from a CS220, that I examined, had the TX circuit inside the search head. I don't know if this is a common feature for CScope, so it might be worth checking the continuity on the coil winding before proceeding.

[morning wood]

Hi all, new here....

I've a cscope cs3mx and looking to build a small elliptical coil, mainly for getting in the nooks and crannies around the trees up the woods. The stock coil is described as 'isocon' and the search head resembles a polo so I'm assuming it's concentric design. I've not done any probing around yet but if anyone has any experience of this machine or similar it would be great to hear from you.

I'm an electronics engineer as a job, mainly microwave/rf so know problem with some of the skills required.

Cheers,

Paul.