Continuous tone! Is the detector kaput?

[SageGrouse]

I started MDing back around 1978 or 79 with a RadioShack Micronta. LOVED that thing and hunted it to death! One day, when I turned it on, it gave forth a continuous tone. Nothing I could do would change ir correct it! it was only silent shen it encountered metal! The exact reverse of what it did before it "fell ill". Unable to fix it, I trashed it with great regret. Well, a few years ago, I found, on EekBay the exact make and model of that first detector! For around $15 or $20, so I sent for it. In the r=original box! YAY! Turned it on and... same continuous tone! Disappointed, I tossed it into a closet. Just found it again, and am wondering... is it also just trashable, or can it be fixed? HALPZ! I want my old beauty back! Yes, I have two Bounty Hunters AND a MineLab Xterra... but I really miss my old Micronta Beep'n'dig machine.

 

[markinmichigan]

If you love it, fix it or buy another. I had a Dewalt 708 12" dual bevel sliding miter saw that I bought back in 1999. Dewalt came out with a "new and improved" unit in 2008 which I bought and was immediately unhappy as it was not half as accurate due to its horizonal slides. Sold that saw and bought a Bosch which I could not keep square. I scoured Craigslist and found a 708 which I still use everyday.

New is not always better. Good luck.

Mark in Michigan

 

[Rammjäger]

In my opinion, it's a problem with the coil. Perhaps a wire is cut at the coil's input. Like what happened to me, I soldered it with tin and the problem was solved

 

[Vito]

I started MDing back around 1978 or 79 with a RadioShack Micronta. LOVED that thing and hunted it to death! One day, when I turned it on, it gave forth a continuous tone. Nothing I could do would change ir correct it! it was only silent shen it encountered metal! The exact reverse of what it did before it "fell ill". Unable to fix it, I trashed it with great regret. Well, a few years ago, I found, on EekBay the exact make and model of that first detector! For around $15 or $20, so I sent for it. In the r=original box! YAY! Turned it on and... same continuous tone! Disappointed, I tossed it into a closet. Just found it again, and am wondering... is it also just trashable, or can it be fixed? HALPZ! I want my old beauty back! Yes, I have two Bounty Hunters AND a MineLab Xterra... but I really miss my old Micronta Beep'n'dig machine.

Hi SageGrouse.
You say the "new" one is doing the same as the one you trashed. If the presence of metal near the coil stops sounding it, I think it is not the coil. The problem should be more of a capacitor or transistor/IC. Having no clue about your electronic/repair skills I'm with @markinmichigan , buy another one or fix it.
On YouTube there is a channel of Radio Boat Anchor. This guy to me explains very well how to open and fix old metal detectors.
If you decide to buy one more just give it a try to fix it.
Good Luck

 

[detect1]

Old capacitors usually go bad, would be easy and cheap to replace them if you or a friend have basic soldering skills

 

[SageGrouse]

Excellent! I also checked with ChatGPT, and it said that a problem might be that its balance is set on the "wrong side" so that it sounds when not detecting anything metallic, but silences when metal is near. I just sent away for an eight pack of Panasonic Eneloop Rechargeable AA batteries, and will test it tomorrow with those. I'm cleaning the battery contacts today (they're pretty pristine, but I'm making sure) and will try the recalibration suggestions tomorrow when they arrive. Failing that, i do know an electrician that's handy with a soldering gun, so we will open the back and see if anything is out of whack.
I know that the Micronta 4001 is an old OLD detector... but it is analog instead of digital, and I learned that signal range VERY well and I liked it a lot. I just seemed to find more with it than all the other detectors I've had. Weird? Yeah.
I tried being normal once. it was the worst five minutes of my life!

 

[hoser]

Another thing to keep in mind is the circuitry is low voltage and as it is an old unit it is not impossible for conductive dust to have gotten in the case and is on the motherboard. It doesn't take much to make a low voltage current path. A can of electronics compressed air or if you have a compressor lightly blow out the case and circuit board. I've seen this work countless times at work. Worth a try.

 

[Vito]

I tried being normal once. it was the worst five minutes of my life!