unusual field and air test for 1236-x2

I have owned a 1210 and 1225-x before so I have some experiance with the 1200 series units.

I took my new 1236 to a park today. I was finding it difficult even at high dicrimination to eliminate pulltabs. Thing is the tabs were very deep in the ground I would say 7-10 in. as an estamate. I noticed that the discrimination did seem to work if I dug the hole or removed a clump of soil containing the tab. It is common for me to set disc. to four and dig alot but in this case I wanted to eliminate tabs and take it easy. It was simply not possable because I would get a good signal no matter with these deep tabs.

Decided to come home and do some air testing on my new unit and observe dicrimination points. I used an old rusty iron nail,Indian penny, Barber quarter, Barber dime, Buffalo nickel, gold wedding band. and clad coins as well as one of the pull tabs I found earlier. I had some unusual results.

First I found the unit with sense turned to a slight backround noise and disc. at 4 to have some impressive to me results. All the coins and ring except the indian and nickel were giving a clear audio between 9.5 to ten in. I expected 8-8.5. The nickel and Indian penny about 9 in.

I laid all the above on the ground and tested. "Strangely"the discrimination points worked just as they should up to about 6-7 in. sweeps off the ground. I raised the coil to about 7-11 in. and bingo discrimintion ceased so that I got good signals no matter what on all the objects except the iron nail with which discrimination worked as it should. Air distance was very good except that the dicrimination seemed not to work at greater distance and gave a good signal. ???

It would seem like I will have to dig alot of deep signals because my discrimination is not effective on them.

Any advice ???

I was going a little fast on this post LoL. At high disc. I always get good signals on silver and clad pennies.

Simply put, it seems that I get more depth than disc. capability. Just can't understand how I would get crackels and pops with a gold ring or pulltab at 5" than a good signal at 7 or 8" stll in disc. mode ??

Greg,

Yes, as with most 'X' series Fishers..... once a target is at a 'specified' distance from the coil (or further)..... discrimination nearly goes away. You are not imagining things.

Would useing the third derivative SILENCER provide better disc. at depth ?

Sorry to be asking so many questions.

No....... filters do not necessarily give any more Disc at depth.

.... I would still recommend the ACE 250 for a mid-line (actually low-end) unit. It'll ID targets correctly to very good depths.

Tom,

I could easily go pick up an Ace 250 in about 15 min. You are the expert and I totaly respect your opinion. Should I do so? I have read that the ace is limited on depth to about 6 in". Would the Ace be a better choice for general use than my 1236 ???

IF you have the opportunity, , , try before you buy. Air-test the Ace 250 at greater ranges/depths....and compare to 1236-X. Even more importantly; if you have the chance to 'test-garden' dirt-test the two units; head-to-head....... do so. In Fla dirt, both units had nearly identical depth capabilities...... but the 250 had slightly better ID abilities at deeper depths.