Testing The Sun Ray "Invader CS-5" Fisher Coil
by Bill Ladd
(Reprinted with permission from Western & Eastern Treasures magazine October 2006 issue)
The Sun Ray Invader CS-5 coil's separation abilities in iron trash helped author Bill Ladd locate large cents, Colonial pewter buttons, and a King George copper at an early home site.
The fan-base for Fisher's latest and excellent digital line of metal detectors seems a tight knit group. Detectors such as the Coin$trike and the new ID-Edge are well known for their "real time" speed in trashy sites, even with an 8" coil. But if these new Fisher units lacked anything, it was a coil smaller than the 8" stock coil. Even though I'd achieved decent success in thick iron, I too was asking loudly for a smaller coil, figuring one would offer these units even greater separation in heavy trash. Perhaps even those "hunted out," iron-laced sites might pay off once again.
Finally Sun Ray came through for Fisher fans with a 5.5" solid concentric coil that they call the Invader CS-5. Building on the success of their small Stealth X-5 coil for Minelab, this coil utilizes the same solid housing. It's called the CS-5 because it was designed for Fisher's top-of-the-line Coin$trike detector. But perhaps the best news for Fisher users is that the Invader CS-5 coil includes an ingenious adapter plug that instantly makes the new 5.5" Sun Ray coil and all Coin$trike coils compatible with the new ID-Edge as well. So, owners of both machines will not have to purchase two separate small coils. The 10.5" Fisher Coin$trike coil now will also work on the ID-Edge.
I believe this adaptor is a fine touch and makes the Invader CS-5 well worth acquiring - there's more! When utilizing one of Sun Ray's helpful onboard probes, such as the Coin$trike's new Invader CS-1, the adaptor is no longer needed. In other words, the probes make coils on both units interchangeable, while the adaptor allows for coils to go from C$ to Edge only. Sun Ray had addressed all possibilities for Fisher owners. In my air and soil testing, the ID numbers on both units were exact, and no adaptor/probe combination had any affect.
Knowing the CoinStrike best, I started my testing of Sun Ray's new coil there to get a feel for it. The CS-5 is lightweight at only 10 oz., and therefore well balanced, with a coil cover included.
My first hunt was at a foundation that had been searched before and was active into the 1900s. A hundred years of activity always equals lots of trash. Along these foundations are many iron square nails from the walls. We'd dug lots of trash and such in past hunts, but really no noteworthy coins or buttons. I was curious to see what the Sun Ray CS-5 could do here. As I began working along the foundation, I noticed that the 5.5" size also forces detectorists into the great habit of overlapping sweeps. Choosing a likely area and covering it fully, I saw lots of negative iron numbers appear on the LCD screen, and was able to slice between this for a little brass piece of a Victorian umbrella, some melted lead, and a brass ring. I felt I was getting decent depth, and not giving up too much more than with the 8" coil. I also found pinpointing with the CS-5 to be a real pleasure, as I dug a plug the same size as the coil and the item was in the plug every time.
Venturing away from the foundation, I discovered that 5.5" was overall a good size to work with, as I own a 3.5" coil for the X-series that's super for thick trash but not open area. So, you could hunt with this size coil anywhere. In the yard I dug a thimble, and a weaker signal turned out to be a flat button. I saw that the ID number was right on - +13 on the button. The hunt ended on a positive note, as I pulled an 1882 Indian Head cent out of the trashy area in back of the foundation. It was the first coin to surface here, and the ID of +20 was correct.
My next two test hunts were in plowed cornfields, first with the ID-Edge & its adaptor. The Edge adaptor piece is just a different plug on the coil wire and very simple. Right away, two things jumped out at me. First, I was able to use a higher sensitivity setting than with the stock coil. Usually, when I'm working in areas of sensitivity 8 is about the max I can use and still keep operation stable. But since the Sun Ray CS-5 analyzes far less soil below it, I could run sensitivity all the way up to 10 with no problem. So, I felt that I was getting good depth with these settings.
Next, I discovered how great the coil is for getting in between those pesky corn stalks. I often hunt these big fields with spoked coils, and the first target had been missed as it was right against a stalk. With the 8" spoked coil, getting too close to a cut stalk can really hang you up. The solid design of the Invader 5.5" eliminated this problem.
I went to the spot of the field where my hunting buddies and I believe a house stood. We have hunted this spot for years with lots of different detectors, yet in about an hour with the CS-5 I came up with five new signals from small targets. This may sound meager, but the coil had great separation and sensitivity to tiny items at a site considered worked out. Not only that, but two of the targets unmasked were cuff buttons of a size that could have been, say, a Spanish half real or cut cob coin.
Wishing to get a full day in with the Sun Ray Invader CS-5, I planned a day off to search another cornfield. This field also has a certain small section, loaded with iron, where we believe a Colonial building stood. It's another spot that has been "pounded" hard for several years now, and I knew anything remaining would be deep, iron-masked, or under/against a cornstalk. I went with the Coin$trike heavy with its larger control box, so swinging just a 10 oz. coil was welcomed, and hipmounting was unnecessary. My first repeatable signal amid the thick iron was half of a fancy brass shoe buckle. This large target must have been buried right next to some iron items to be missed for so long. I had to be patient and overlap sweeps to tally up signals that were few and far between. Nevertheless, I was encouraged to have separated the iron to get to three Colonial buttons (two pewter) and two small copper coins (one cut in half). Soon the farmer began plowing for his summer crops, so I decided to break for lunch. Walking back to the car, I dragged the CS-5 coil along the cornstalk line and got a solid +35 signal. Up came a really worn early large cent - only the back wreath and 1/100 remained. Again, the big coils had missed this coin because they couldn't get in tight enough.
After lunch, the plow discs had roughed up the topsoil as the farmer finished up. So, I decided to head right for the same trashy, iron area with the 5.5" Invader CS coil. The field was now powdery, and it was tough hunting; but more small buttons began to surface, thanks both to the farmer's shifting iron around, and to the coil's ability to get in between it. I dug a small cuff button with a fancy swirl pattern, and a small square piece of lead that looked like a crude dice. My next signal ended the day with another coin, an 1850 large cent with good details. It read a solid +32.
Michael King, 8, found the new Sun Ray Invader CS-5 coil lightweight and easy to pinpoint, making finds along a bike path near his home.
To conclude testing, I allowed an 8-year-old boy to try it on the ID-Edge. He'd used my Edge originally with the stock coil, but handled the smaller size far better. As a beginner, he was able to pinpoint far better by digging a plug the size of the coil. Basically, I let him go and find his own targets with the preset "coins" mode. He found several Wheat cents in the yard of his older home, along with a skeleton key and a nice, collectable religious medal from a 1930s parade. Again, this coil proved itself versatile enough to succeed anywhere. It's not just for thick, trashy sites, as the little guy and I took it everywhere. I now keep the Invader CS-5 coil in my trunk, mounted on a lower rod and ready to go whenever a smaller coil opportunity may arise.
For further details on the Invader CS-5 coils, probes, and other detector hobby accessories offered by Sun Ray, be sure to visit their website: www.sunraydetector.com or see their display ad on page 17 in this issue. Also, feel free to contact Ralph at Sun Ray at (319) 636-2244.