19 khz going beserk

[irnwrkr]

Went to a local park, there are no over head lines. I was hunting in 14 khz then switched to 19 khz. Gain was up in high 80s, and as soon as I changed frequency the machine went crazy. I haven't had the chance to try the machine at any other locations as of yet. Has anyone else had this happen yet? I'm gonna guess it's underground emi

 

[Electricfrontporch]

Did you GB after changing frequency?
Also did frequency shift help at all?

Sometimes EMI will affect certain frequencies more than others.
Thats what's nice about having the option of 3 plus the shift option.

 

[irnwrkr]

Yes I did gb again after changing frequencies

 

[Monte]

Went to a local park, there are no over head lines.

There doesn't have to be overhead power lines, a transformer on a pole, or underground power lines. You can have electric lines underground to go to park lamps or to power other things. More often than not, detectorists can not see the source of the offending EMI problems. It can be from a nearby business or some type of RF generating source, be it an emergency service or a commercial business that is making the unnoticeable interference. It can also be generated by a mobile source in a truck or other vehicle.

I was hunting in 14 khz then switched to 19 khz. Gain was up in high 80s, and as soon as I changed frequency the machine went crazy. . Has anyone else had this happen yet?

Yes, and often we have issues not necessarily related to the operating frequency. As an example, several years ago I was hunting some torn-up sidewalks in the Chinatown section of inner downtown Portland, Oregon. I was using a White's XLT w/6½" Concentric coil and that unit operates at 6.59 kHz. I wasn't having any detecting issues at all, and after finding an 1887 Seated Liberty Dime, a 'V' Nickel and several Indian Head Cents, I crossed the street to take some medicine and insulin and decided that, since there were a lot of iron nails, I might want to use a different detector with a slow-motion/quick-response.

I grabbed my White's modified IDX Pro, also using a similar 6½" Concentric coil and also operating at 6.59 kHz. I crossed the street and turned the detector on to ground balance and there was no way possible. It was so terribly noisy you couldn't hear a signal from a Lesche Digger! I went back and exchanged it for the XLT again and continued to hunt the very same area with the detector being very stable. No noise and, as usual, I had my Bushwhack program loaded and that is set with a high Gain level.

I'm gonna guess it's underground emi

Could be a good guess, but then it might not be. Keep I mind, also, that some areas of EMI are only periodic and you might find some sites unhuntable or with very annoying EMI on certain days or periods of the day. I have encountered this many times in bigger metropolitan inner-city areas during weekdays from perhaps as early as 7 AM to as late as 9 PM, and the locations were NOT where I wanted to hang around between those times.

But on weekends, the source for the very intense EMI wasn't in operation and I could hunt with any detector and they stayed very smooth and stable, and it didn't matter what operating frequency they used.

This is one reason why I like the Multi-Kruzer or Nokta Impact, because I have frequency choices to make that can help me deal with the unknown interfering challenge. That's also why I have several detectors in my personal battery and travel to most detecting sites with at last 2, and usually 3 or 4, detectors along just in case one unit encounters EMI problems, then I just select the model that works the best for the EMI conditions at the time.

It's 3:05 AM and I just came in from getting my Tahoe ready to go in a couple of hours, and it now has an Impact, Racer 2, CoRe, Relic and MX-7 loaded. Headed out early to check out a couple of ghost towns before we get several days of cloudy and rainy weather, and I like to go prepared for different environments and search opportunities and challenges. That includes operating frequency consideration as well.

Just enjoy the Multi-Kruzer and the ability you have to select the operating frequency that provides the best all-around performance at the time.

Monte

 

[Coin Rescue Inc]

I use 19 kHz most of the time - in 4 tone - 88 gain - Iron tone set at 3 to semi mute iron sounds

A week ago I had a lot of chatter in a park close to a school. I dropped the gain into the 70's and the chatter calmed down quiet a bit.

Been unseasonably cold this spring putting a damper on detecting. That day was 35 degrees and windy. So I my trips have been short and still gaining experience.

 

[Cal_Cobra]

You can't see EMI, so could be coming from any number of sources.

Interestingly I find that 5kHz is typically the most EMI affected frequency, don't recall ever having issues @ 19kHz on the MK, or 20kHz on the Impact.

 

[Dan-Pa.]

Heck the other day turned on my CZ and ford fusion trunk opened....old days were bad enough but with I-phones and hand held devices who knows...