Depth modification of detector circuit boards.

[Getoffmyland]

I was told that MDs are radio transmitters so are restricted to stop the frequencies getting out too far. This would definitely restrict depth.

I know a slow swing speed is an easy thing to do to improve depth.

On vintage detectors you can get onto the PCB and potentially modify them.
I remember the Fisher 1266 having PCBs with accessible components.

Any RF Engineers out there tried improving depth? Or can advise where to start?

Maybe its as easy as using a higher voltage to the circuit( I know this will drastically reduce the life of some components).

Perhaps it will be inductance to change or both resistance and inductance. When I get one it maybe it uses PWM and I can look there

 

[Listener]

There are plenty of MD’s out there that already get plenty of depth. It’s getting beyond the garbage in the ground too get the goodies that’s the issue. Who wants to spend their life digging deep holes when there is plenty of stuff to be found but is masked by trash. Something that can do that effectively is the answer.
The most profound topic on this I have read was written in the March issue in 2000 by Tom Dankowski titled Beneath the Mask written in Western & Eastern Treasures magazine.
Check it out before you change the guts of any machine and get yourself in Dutch with the FCC.

 

[Getoffmyland]

Wow, what an interesting read that was.
Thankyou for this informative reply.

For anyone interested in my thinking process on my first post..

I am in the UK, in Suffolk. There are fields around the Sizewell power station that are baron of anything including Iron. Very unusual in the UK.

The article has made me think a PI detector may get me past the top soil.

With new Sizewell building works, dozens of archaeologists over hundreds of top soil scraped acres are finding lots of early human activity.18 inches and deeper. Along with activity from later long- gone early industry judging by some of the dig sites.

Local Celtic gold finds suggest there was wealth here. Saxon boat burials and viking raids all around.

I enjoy speculative detecting, just me and the bewildered wildlife!

Back to Lidar and maps etc....

 

[Ism]

Think of a target as a bell. The soil as the atmosphere. The detector transmitter as the bell striker, and the receiver as your ear.
No matter how hard you strike the bell, the sound is only going to travel so far depending on atmospheric conditions and size of the bell.
The larger the bell (target size), the further from the source you can hear it.

You can have the most powerful transmitter on a detector, but the target will only retransmit the signal so far (depending on target size and soil conditions).
You can increase the sensitivity of the receiver, but that will amplify all noise. That makes it like trying to single out a single conversation in a crowded room full of people talking with loud music playing.
That is the limitation with the current tech.

 

[DWerk]

Just as the CB'ers did in the past to exceed FCC rules and as Ham Radio Operators still do you could build an amplifier to place between the coil (antenna) and transmitter (detector circuit) to increase the output of a detector. Of course you can also increase your depth of detection by using the common known things; keep your coil to the soil, use lower frequency (mono), detect when the soil is moist/wet, GB, adjust detector settings.

 

[cw3]

Minelab had an inline amp for the sovereign detectors.

They didn’t catch on.

 

[Getoffmyland]

Minelab had an inline amp for the sovereign detectors.

They didn’t catch on.

Didn't know that. I will see what I can find on it. Thanks

 

[Picketwire]

Amplifying a signal just makes it louder, not deeper. If the detector won't hit a dime at 10 inches, making it louder isn't going to make a difference.

 

[cw3]

Amplifying a signal just makes it louder, not deeper. If the detector won't hit a dime at 10 inches, making it louder isn't going to make a difference.

The amp I posted a picture of sends more power to the coil. It goes between the coil and detector.

It will make a detector go deeper.

The amps for headphones don’t make a dector deeper

 

[Picketwire]

More power to the coil doesn't necessarily make it deeper. I can increase the transmit power to my Deus coil but in my high mineralization areas, it is counterproductive.
Here is some information from Dave Johnson, engineer of many great detectors;

David Johnson Statements that helped me

 

[Rick(ND)]

I think that amp pictured is not A Minelab product as it dont have the Minelab name on it. There was guy that built some amps for the Sovereign and I did a test on one and seem to make the Signal a little louder, but I found the depth a little less or the same. I found that listening closely to the signals is more important as those deep ones are weaker signals and the louder signals drown out those weaker one.
For me I could do much better without the amp than with it. I dont know if this person built them or not after I did the test.

Rick

 

[OldBeechnut]

More power to the coil doesn't necessarily make it deeper. I can increase the transmit power to my Deus coil but in my high mineralization areas, it is counterproductive.
Here is some information from Dave Johnson, engineer of many great detectors;

David Johnson Statements that helped me

Maybe not the D2 but it does to some others, TDI PI's were famous at getting more depth when voltage was increased to 16.8/18./21 volts and like any detector had a lot to do with the conditions if you could use all the extra, but it was good to have it available and when used it, it was deeper. I used Shaun's Amps for a several years both the Sovereign and Excalibur. Having that extra power proved to make the difference in most places I hunted. On average, depth increase was about 2, maybe 3 pushing it. In the day I could walk behind any hunter and hit deeper targets they were missing, mineralization was never a issue. Now It was useless in trashy areas.. so it got turned off. I put it on my Excalibur, drysand it was a killer, once I hit the shallow salt water.. she let me know ..turn that thing off. I never use it in fresh waters.

Shaun's video
.

power was provided by a separate power pack 12.6 full charged

Amplifying a signal just makes it louder, not deeper. If the detector won't hit a dime at 10 inches, making it louder isn't going to make a difference.

True to a point, but Are you hearing everything your detector is telling you? I would imagine you are with the New detectors having modulated audio now days, D2..Noxs and etc. For us all metal Threshold hunters , "are the head phones/speakers loud enough to hear those little faints". ...NO... One reason doc's detectors sell so many amps is.. to help gold hunters hear the details. https://docsdetecting.com/categories/gold-screamer/
And one reason My AQ PI and xcalibur in all metal can pick out those deep faint golds signals that everyone else walks past. A better than stock set of head phones with some machines can make all the difference..

 

[Odanscoils]

The amp I posted a picture of sends more power to the coil. It goes between the coil and detector.

It will make a detector go deeper.

The amps for headphones don’t make a dector deeper

But they let you hear whisper signals quite well.
Been there done that.

 

[DWerk]

There is a big difference between a Signal Amplifier and an Audio Amplifier..

 

[OldBeechnut]

Shaunfth was a very gifted electronics engineer who made the "S" Amp and he was a beach hunter.

Here is Shaun's Signal Amp on the excalibur and how much the send field is amplified. I use a audiosears 2463 speaker/microphone to pick up the send field. Interesting is how the 2463 can show the strong and weak areas of the send/transmit field.

Years ago I seen this on Doc's web site and it had me wondering. I found it did not help on several machines but did work great on PI's, except the Whites DF and the Garrett LS Infinium PI's. And just how Doc describes how to set it up is just how it works in all metal, and this is a "Audio Amp". These targets are so faint a little boost brings your attention to them, where as with out they maybe missed.

I could go on and on about what I have experienced the last 16 years but these are all my opinions on what has worked for me at the beach and in the water. For sure I've been very Blessed in my quest for gold.

 

[Rick(ND)]

Interesting what I can read, but myself just run a slight threshold and those deep coins or trash with a null lets me know there is something it is seeing. On the good target it may give a slight tone and by working this signal with the Sovereign wiggle I can hear the tone changing getting better, but may not read correctly as it is deeper and sure wants to get better. .
Now my hearing is bad and why I need the best headphone in order to tell the deep targets, I use the Timberwolfs and the Bushmaster as they work the best for me. I have tried different amps that go between the detector and head phones and they just dont do much for me. This is why I havent found any amp that will make me get more depth, but some of it is how people use their detectors as some run with no threshold and miss those weak deeper signals.

Just my opinion and what works for you is good to use, but maybe it wont work for me.

Rick

 

[cw3]

Thanks again for the amps Joe.

I got a laugh seeing your battery. Mine is a little overkill. I’ll never run out of power in a day detecting. I use 10 amp hour lithium ion for ice fishing fish finders. They only weigh about 1 pound.

I hunt fresh water I’m positive these will work just fine. I have a spot you need every mm of depth you can get. You can walk around for 45 minutes and not get any signals at all.

I’m finishing up a couple cars then it’s detecting.

I used to running in all metal and running the detector hot.

 

[BobOso]

They used to make a device called the depth master, it went between the detector and headphones. It simply amplified the signal to the headphones, still have one somewhere, it is just a pre-amp.

 

[cw3]

I could go on and on about what I have experienced the last 16 years but these are all my opinions on what has worked for me at the beach and in the water. For sure I've been very Blessed in my quest for gold.

I appreciate the information you share.

I'm saving all I can to build an Excel mods database.

 

[OldBeechnut]

They used to make a device called the depth master, it went between the detector and headphones. It simply amplified the signal to the headphones, still have one somewhere, it is just a pre-amp.

Came across this pic while looking thru my files, worked like Doc's treasure screamer.