Simple solution to EMI!

[CincinnatiKid]

Thanks devilpookie. That is not what I wanted to hear though as I will soon test mine directly beneath power lines. What places on the beach were you when this occurred? And in those places, did you notice any obvious cause for interference?
Peace

 

[devilpookie]

There is no indication as to why these spots have this strange forcefield around them. No powerlines, buildings, or anything else that I could see that would cause this. I think that is why I was intrigued with the EMI filter to begin with. If there was powerlines or something nearby it would have made some sense to me but, I don't know. I will try that area with the V3i this weekend, provided there aren't 5 million surf goons there, and see if it has the same effect.

Thanks devilpookie. That is not what I wanted to hear though as I will soon test mine directly beneath power lines. What places on the beach were you when this occurred? And in those places, did you notice any obvious cause for interference?
Peace

 

[CincinnatiKid]

I just realized that a "Full Member", Jeff In North Georgia , sells this device. Same price as the Shack too. It's listed as; In-line Filter, fits coil cables for Fisher,Whites,Minelab,Tesoro,Garrett,Teknetics,etc. $5.95.
http://www.ebay.com/itm/251391197600...84.m1558.I2649
Peace

 

[Rawhide]

I would avoid overhead power lines as it could damage your detector. Also the 11" inch coil is super sensitive, you will want to use the small 5" coil as it is less receptive to emi also.

I just had my F75 repaired and Fisher threw in some freebies. If I had used the rain covers and the coil cover sent I would not have had to have repairs done. I am very gentle with my equipment and the F75 is built very well. You have a good machine there, get those covers on it.

Coil covers and rain shields are after market stuff, just like head phones, gloves, diggers and everything else. You really want to pick out the items in your price range and what you want to use. They keep the price down that way.

I dont know why they put power lines in some of the best spots to hunt but they do. It is worst on the dry days. I planted a garden under power lines one year, and it all came out deformed. I would avoid power lines if you can.

 

[CincinnatiKid]

Thanks again devilpookie! But do you realize that you just said "surf goons"!? Lmao. Dude, I have 6" of snow! Let me know how the V3i works out. Peace

 

[CincinnatiKid]

Thanks again Casca! When I leave the "power line" site, I glow!? But the site is dated to 1800! There are 3 cellar holes, untouched, as far as I can tell. The power lines were installed mid 70s. Before that time, detectors only found ground, 1-3" depth items. If I can somehow negate EMI, finds/relics should be bountiful. Peace

 

[Rawhide]

I use my propointer around large iron and problem areas. Its slow searching, but it gets the job done. You may just want a large industrial magnet to pull the iron and do some sifting.

 

[CincinnatiKid]

Casca, I would never have thought of that. U da man! When my TID numbers "freak out" under power lines, I usually don't worry. I can detect by sound on every machine I've used. But, these power lines send ALL detectors into overload. Especially sound? It's so bad that it seems like a "hot rock" is taped to my coil?
These power lines do follow a once, small rail line, that brought people and goods, up a steep incline. Horse n Buggy could not ascend the extreme hills. The RR blasted/leveled, some of these, and the heights of our town was conquered. Now all power lines follow this route. Bad for me. I will try all available options to EMI. Peace

 

[foiler]

CincinnatiKid, to answer your question I must tell you first I'm no electronic whiz. I do have some experience though in the field albiet years ago. As to the 705, it uses what Minelab calls "V-Flex". A proprietary technology they developed that allows you to have a single freq. machine with multi freq. capabilities simply by changing the coil. The 705 operates at 3K, 7.5K and 18.75K. There is a chip in each coil that links with the machine. That communication allows the main processor to identify EMI that may be affecting it while in operation. It then can shift the coil freq, two steps above or below the set freq the coil is tuned to. This is done automatically. There is a step to do this prior to ground balancing which also is automated if you choose. It takes 15-20 seconds for the machine to evaluate the extent of EMI on the machine and shift the freq to the best one. I might add that multi freq. detectors unlike the 705 are always affected by EMI and must be adjusted accordingly because they are constantly scanning through all the machines freq. settings. Whereas a single freq. machine is affected only if the EMI is within its freq. range. Hope this helps.

 

[CincinnatiKid]

Thanks foiler. You are an absolute cornucopia of information!
I did know of the 3 coils you mention for the 705. Can the 705 change between its 3 frequencies with a single coil, or are frequencies changed when a different coil with a different frequency "chip" is attached? Either way, it would be useful.
I'm seriously considering a Mlab purchase. Never owned one. If purchased, I will certainly get an E-Trac. With 28 frequencies running simultaneous, are they actually better than one "strong" frequency featured on most detectors?
Peace

 

[foiler]

The E-Trac is a very nice all purpose machine. Allows you to do just about anything. For my purposes the 705 is a better fit. And to answer your first question, the coil determines the frequency on the 705. There are many to choose from with each of the 3 freq. having different sizes in both DD and concentric mode. As to whether multi freq. is better than single, well you will get a lot of discussion about that. I prefer single freq but with the 705 I'm able to utilize additional freqs merely by changing the coil. It works for me.