Broken 9" 7.5 KHz coil-replace with 9" concentric or 10" DD

[jnw8w8]

My mom has a X-Terra 70 and broke the ears off her 9" 7.5 KHz coil while trying to pull the lower shaft off. I told her that I would order her a replacement and get it to her ASAP (she is detecting on the beach for the next two weeks) and just noticed that there is another 7.5 Khz option compared to the 9" 7.5 KHz concentric that was originally sent with her detector. She currently has the 18.75 KHz in 6", 10" and the 5" X10" elliptical but I was just wondering if the 10" 7.5 KHz DD would be a better replacement for her for coins on the beach and on parks. She is 85 years old and in better health than I am (probably owing to all the swinging of the coil and squatting to dig) but if there is a significant weight difference between the concentric and DD that would be nice to know as well. She has mentioned to me in the past that she prefers the 6" coil to the 10" in the 18.75KHz frequency I think because of how it seems to pull down on the end of the shaft with the additional length or weight. We have tried to mount the coil backwards but she is a little short and the angle of the 10" coil when reversed creates a bit of a problem as well. Thanks in advance

 

[Old Longhair]

Given the circumstances, I'd be inclined to either get her a 6" 7.5kHz concentric, replace the 9", or repair the 9".
Being a tightwad and fairly handy I personally would do the repair. But if she wants something as light as her 6" HF, and doesn't mind the possible depth loss over the 9" or the overlap required, the 6" MF CC might be the ticket.

 

[jnw8w8]

thanks longhair, I am not tightwad averse! Do you just cover the parts with a lot of epoxy and let it cure or is there a solvent or plastic welding technique that will hold the coil ears on with enough strength that you could recommend?

 

[jspoon]

I just replaces my stock 7.5 CC that came with my XT505 I noticed an immediate difference as the coil feels more nose heavy. I just purchased my XT505 in Jan and I'm selling my 7.5CC, it's like brand new.

HH

 

[Old Longhair]

Do you just cover the parts with a lot of epoxy and let it cure or is there a solvent or plastic welding technique that will hold the coil ears on with enough strength that you could recommend?

I've seen epoxy, fiberglass, and delrin replacements fitted & glued in.
I have a plastic welder and am contemplating giving it a whirl, but unless I actually beef up the ears some it likely won't be any better than the other fixes.

 

[Woodstock]

I've actually done these repairs with both a plastic welder and a good quality epoxy . I used 5 minute quick-set and then standard over that . I've even strengthened damaged ears adding plastic " L " brackets ( holes pre-drilled ) and added them to both damaged ears . I'll important to make sure the glued surfaces and clean and scuffed with light sandpaper to help them adhere . Fix them or try to before you invest in a new coil . HH , Woodstock

 

[michaelosully]

Might just mention that if the unit is still in warranty, Minelab might take care of your problem! ...worth a shot as I know they have replaced 'broken ear' coils in the past. Think most of the broken ears occurred on the 10.5" coils but it costs nothing to call and ask. Doubt you could get it taken care of in a real short time-span but hey, this advice is worth just what you are paying.