Anyone own a large SEF? 15x12 or 18x15?

[Whitetail]

Just wondering if anyone has one of these large coils? I know each has its place. Just wondering if the 15x12 for example would be that much better than the 12x10?. You have to take everything into consideration weight included. But for a short hunt where you might want more depth, I don't see why swinging a 18x15 in a field wouldn't be a good option if it got better depth than say my 6x8? Just curious if anyone has tried them on the MXT?
Thanks.

 

[dan93]

I have both for my MXT the 15x18 is great on open sports fields but I recommend not getting one because of the size and it doesn't get any more depth on coins only good for coverage it is brutal to swing also, it is collecting dust now. I fell for the claims of 16" coins, it is BS. I recommend the 12x15 on sports fields it works great and is not too heavy.

 

[Aarong81]

I've never used either of those coils but...
I always imagined that a coil sends 100% signal out and receives a certain amount of signal back from metal objects. A large target bounces back more % signal than a small target. And the same size target bounces more % signal back when using a small coil than it would if you used a large coil. If targets always matched the size ratio of the coil, the bigger coil the better. Although, thats just not the case. Small targets require small coils just for the basic fact that small targets cannot bounce enough signal back to the large coils at any significant depth. Thats why nugget hunters use tiny coils because very small targets bounce very small signals back to the coil.....but if you use a small coil, the % of signal bounced back is much higher.

If bigger is better, the 8 foot x 8 foot coils dragged behind 4 wheelers would work great at finding seated dimes at 4 feet deep. That size of coil would require targets the size of cannon balls just to get a signal.

On the other hand, if your looking for targets the size of belt buckle plates and larger then the big coils can see those deeper than smaller coils. Even the 300mm or super 12" coil misses dimes at depths that the 950 can still detect it just because of the target vs coil size ratio. Although, the 12" coil may see quarters or half dollars deeper because for the 12" coil a quarter is aprox the same size ratio that a dime is to the 950. Targets smaller than a dime may require even smaller coils yet, at least when going for greatest depths for the same target. That spent .22 lead bullet shows up at 5" with the 950 but is non-existent to the 12" coil beyond 4", ect.