I've gone wacko, but...

[slingshot]

Took out my Garrett Hunter BF0 (circa 1965) and switched to 3 1/2" coil for testing. A handful of paperclips caused a slight decrease in beat but when a 10K ring was placed under them it quickly increased in frequency. Not a single nail or screw such is in most photos when they show an a/m hunt was found. I DID find the metal butterfly hair pieces, etc, without finding the nails, bolts, and other crap. It was such an eye opener that I'm going to build one w/4" coil and call it the totlotter. I had been reading all the posts about target masking and how most detectors won't pick up the small gold chain-even in the a/m mode-and sure enough my Silver umax and all my other detectors (except the Royal Sabre, which has a true a/m pinpoint mode) would! Well, the bfo did and with the natural iron elimination I just couldn't help but see the potential. That's all I used for 3 years and now, at least in tot lots, that's where I'm returning!

 

[tabdog]

Go for it Sling Shot.

Being conventional dosen't help that much.

Maybe you got something.

Hope so,

 

[slingshot]

Thanks, Tab. You're the one who opened my eyes on this 'cause I was so bent on getting a Compadre(and am STILL thinking about it). I saw all the nails,paperclips,bolts, etc. and then experienced one full day of hell in the a/m mode digging all this stuff. Trouble was, I knew that if I was going for the gold I was going to have to change! Then, I remembered the old days(don't we all) and how the natural characteristic of a bfo was some discrimination on iron-though not much. I guess we were so concerned about foil and tabs back then we didn't appreciate what we had. To my surprise, the SMALL gold chain that was ignored by all my detectors except the Royal in pinpoint was easily picked up by the bfo. My second shock came when I placed a bunch of paper clips over a 10k ring and could only pick it up in the a/m mode w/all my other detectors-BUT when these items were separate, the paper clips were ignored by the bfo(slight decrease in beat), but I couldn't ignore them in the a/m mode w/my other detectors. IN other words, I'm hoping that for these particular sites I have the best of both worlds-gold w/out nails, etc. The 4" coil came into consideration in case of high mineralization-as the larger coils had trouble w/mineralization in getting a loud enough response to the small stuff.

 

[tabdog]

I would be interested in your impression of the set-up.

I have often thought about a BFO or PI.

But the iron issue bothers me.

Garrett and Whites I think now have PI machines with some disc.

But they are out of my price range.

Happy Hunting,

 

[slingshot]

I was thoroughly impressed and think this setup will work for tot lots and similar school yards. l have made it a practice to take the trash from my favorite school yards w/my Silver and so they should be relatively clean. I noticed that when I used the 8" coil the signals were faint and I had to listen carefully-though I could go deeper on larger targets. But coins and jewelry give a good "zip". Also, in mineralized ground, the 8" coil was very faint on the small stuff but the 4" coil really kicked them in and would be the best all around coil. I still found the costume jewelry like the butterfly hair clips and small hair clips that seem to be made out of tin or something. I found, of course, the small foil, and other regular nuances. But the nails, paperclips, bolts and nuts were nonexistent-and when passed over they only slightly caused a downshift in beat-you probably wouldn't have noticed if you weren't watching. Of course, the '60's Garrett setup is awkward and uncomfortable, so I'm either gonna cut up a relic and make it comfortable or build one with micro-components and put it in a walking cane so I can carry it anywhere without being noticed. I have several schematics using a single IC chip-I'm excited. It won't by no means replace my Silver-but I think it will bring home the bacon in these specialty areas.

 

[slingshot]

Sorry- I forgot to mention-important to you. THE part that got me was piling paper clips in a clump and listening to the slight decrease in the frequency beat and THEN putting whatever as far as gold under them and listening to them being picked up as if the clips were not there!

 

[Steve(MS)]

I had one back in the very early 70's when I was only a kid. I will never forget that motor-boat sound.
The one I had was a cheap one but I was still able to find silver with it. I think mine had 2 knobs, one for tuning and one for disc and it was red in color, can't remember what the brand was though.
One of these days I want to get another one, just for memories and to play around with.
It should do good for what you intend on using it for, let us know how it works out.
Sometimes old technology has its advantages.
HH

 

[Tom_in_CA]

Slingshot, the items you give an example of, that had a distinctly different sound than the gold ring, are iron (paper clips, nail, screw, etc....) Yes, it was no secret that the old-time BFO's, even though they were "all-metal", had some audio characteristics to allow the user to pass some iron. But the real test would be to put down various aluminum items (tabs, beaver tail, wad of foil, etc...) and see if THEY sound different from your gold ring. I don't think they will.

 

[david bull]

Last summer I purchased an old Whites Goldmaster in mint condition(complete with hard case&both coils ) at a yard sale.I put batteries in and played with it.It too would totally ignore iron,but would really sound off on a gold ring! By the way,I traded it for a coil for my xl-pro at lost&found treasures in Lynchburg Tn thanks DBULL

 

[slingshot]

Some old timers are proficient enough to just about tell what their bfo is telling them. However, I'm going to use this as Tab suggested in finding gold and the intent is to do away with as much iron junk which other detectorists ignore and leave in the ground. I know that I'll find these other pieces of junk-but the amount of nails and paperclips,etc can sometimes be staggering because other detectorists disc them out and they are left behind MORE SO than the other junk. In other words, I'm going to try to eliminate as much BELOW gold WITHOUT losing the gold-and the bfo SEEMS to have this capability. Foil, beaver tabs, etc. are PART of the GOLD game!! The 15 khz Compass TR was good for ignoring iron but sent the threshold and sensitivity down, while the bfo still has a beating threshold so the background is not lost. Being able to at least ignore but SEE THROUGH iron will save the back and much time. And items like pocket knives, money clips, etc. are still picked up-try THAT with another detector!