Going to test Shaun's Amp this Weekend

[goodmore]

The wife and I are heading to the Jersey shore this weekend. I want to pair up the Amp with my favorite S-12 beach coil and crank em up. I want to see if I gain that extra couple inches on the Sovereign. I need to get in one more beach hunt before the cold sets in. I played with the Amp in the yard and it seemed to do what it was advertised to do. I need to find a couple deep targets in the sand and switch it off.

 

[ToniSteve]

Looking forward to your testing! Hope it works great, please let us know the details.

Thanks,
Steve

 

[w6pea]

Goodmore;

Question did I miss something about an Amp?
Do you have a link?

 

[OldBeechnut]

Goodmore we have to hook up, like to test the Treasure Amp against Shaun's Amp..I have been looking for Shauns Amp for awhile just missing out on a few deals. His is a True Amp were Doc's Treasure Screamer is a sound Amp, it just open's up what is there already. I guess you would say one is at the coil, the other is at the headphones...I'm near balitimore, let me know...thanks joe


http://www.youtube.com/watch?v=Y8v0lBff1lU

 

[Critterhunter]

Everything I've read on this amp thus far has been positive. The only negative thing I've read is that I think it won't work with SEF coils, but some claim using the stock 10" Tornado they are getting deeper than any larger coil including the WOT or SEFs. I did talk to one guy on the phone using one who said it would not run stable in his high mineral soil despite any setting. Others have said that with it ON they can get a solid coin hit at great depth, while if they turn it off the Sovereign would do nothing over the coin or just null. Building something similar is one of my winter projects, as I can get lipos cheap (I think he is using a 4 cell lipo on it to power the increased voltage output to the TX windings) and have an electrical engineering friend to walk me through what I can't figure out. I know my way around many aspects of electronics but when it comes to oscilliscopes I have yet to learn that field. If I put something together that works I'll probably post some plans for it. Rough cost estimate to build one (including a cheap lipo) would be probably south of $30. The way I understand it (might be wrong) he is increasing the voltage output to the TX windings, but also is using an adjustable RX pre-amp to tame down the signal. Increase the voltage to the TX coil and the size of the magnetic field increases/becomes stronger. RX gain control (like your sensitivity dial) just raises or lowers the gain on the received signal, not really increasing the depth of the coil but the sensitivity to the received signal. Both have pros and cons.

 

[OldBeechnut]

one of my winter projects

Your the man...CH.I like winter projects, keep me up on that one.......................joe

 

[Critterhunter]

Will do. Of course you know that "winter project" is just code word for me drinking a bunch of beers in the garage and ignoring life for a while.

 

[plugger]

n/t

 

[synthnut]

I'd like to hear more about Shauns amp, and why did he stop making them ? .....Who's making the replacement to Shauns amp ? .....Thanks, Jim

 

[Critterhunter]

OK, I've got some encouraging news. Talked to my friend last night about what I wanted to do. He's not into metal detecting but he is an electrical engineer and builds custom video transmission antennas as a hobby. He's the guy I fly RC planes with and he's been doing a lot of FPV (first person view) via live video feeds to a ground station. He's been building his own antenna designs to transmit further distances using low wattage transmitters, which is kind'a similar to this project in certain respects. Metal detector coils are really just antenna's anyway. He also designs his own brushless three phase RC motors, which in some ways also has many similarities to the science behind coil windings for things such as metal detector coils, so he's got a lot of background in related electronics fields. I gave him a general overview of how the Sovereign works, the multiple frequencies being transmitted (one at a time), the pre-amp in the coil on the RX side, the normal voltage level sent to the TX winding, and so on.

The good news is he said I probably wouldn't need an oscilloscope to build the thing, since you'd only be taking that signal and increasing it's power output (hence the need for a higher voltage lipo pack) to the TX windings. In fact, he's already got an IC chip in mind that should work perfectly for such an application. I'm going to be sending him a few schematics for input, including the RX pre-amp layout inside the coil and the TX transmit circuit inside the Sovereign. Have to give him the resistance value at the TX coil and a few other things, then he can offer input and opinion on how I should go about building the circuit.

There are a few pros and cons to increasing the TX signal strength. Mainly you reach a saturation point, but that's why the unit should be adjustable. Probably a POT for adjusting the output signal strength to the TX coil, along with a 2nd stage gain control on the RX side between the coil pre-amp and the Sovereign's internal gain control (sensitivity).

He was pretty positive about the fact that it should be an easy design and build and not really all that complicated, but there are areas in building something like this that are well beyond my electronics knowledge, so I'll be relying on him heavily for input and advice. Once I've got something I'll be posting a schematic and parts list, along with where to buy a cheap lipo to power it. He agreed that it should be a pretty cheap project, with connectors, lipo, and internal components probably well south of $30 or $40.

I'm all about building things myself especially when I can do it cheaper than buying something, so this is the kind of thing I love to sit and tinker on in the garage as a good excuse to sit around and pound some beers. Or should I say home made wine, as I've just started into that hobby and am currently brewing my first batch which is pear wine. 6.5 gallons of R&D.

 

[Critterhunter]

Sorry, dug back through some old messages on Shaun's amp and it appears some are using it with the SEF coils. Not sure where I thought I read that. The only thing Shaun says is that it won't work with the Detech concentric coil. Also dug up a few amplifiers over in the UK for the Sovereign, but those are just RX signal gain devices with an adjustment dial. Really I wouldn't think anything like that would work since you've already got a gain control (sensitivity dial), unless they are using very high quality components that allow you to raise the RX signal gain with less noise contamination then you would get if you raised it by the sensitivity dial on the machine it's self. It appears Shaun's amp also has an RX gain control which will work whether the device is on or not, but it's main claim to fame is increasing the power to the TX coil, generating a larger magnetic field and thus detecting deeper. I think he said that the stock 10" Tornado goes deeper with this amp than his WOT and I think he said the 15x12. Found a few reviews from guys who are using it and they all seem to indicate increased depth with the thing, so it looks like a quality product that really works. Just hoping I can make something similar on the cheap.

 

[JOHNMARKHAM]

please all keep me posted,as i understand this, were wanting more voltage to the coil?? increase depth?? can you not do the same to a point by shortening the coil wires?i was told that the fcc made a manufacture make the wires longer to decrease the sensitivity on the coil,not sure if this is correct,but im just asking for info?but if you increase voltage to coil sensitivity will increase but then your coil will run much much hotter and just might burn out quicker,not to say itll burn right up but life of coil might be shortened a bit?
where can i read about shauns amp???im a bit interested on this too.
thanks
john

 

[OldBeechnut]

CH............................[size=large]Your our last hope[/size]......out of stock.........How much beer money do you need for this project, paypal OK?

Good Luck, Keep us up on the progress, always enjoy reading your post.....joe

http://www.findmall.com/search.php?21,author=11344,match_type=USER_ID,match_dates=0,match_threads=0

 

[Tony]

Hello everyone,

This is what I know about Shaun's AMP;

1. I wouldn't sell mine for $500
2. I am getting somewhere between 15% and 20% depth increase
3. I cannot get the Amp to work on the large SEF coil or WOT coil.....regardless of power settings
4. I only run AM/PP as the power can swamp the DISC settings and it will NULL

......I will now make this following statement which I'm sure will get me howls of protest;

For my local beach environment.....the Sovereign GT with stock 10" coil with Shaun's Amp is the DEEPEST DETECTOR THAT I HAVE EVER USED ON THE BEACH. It beat my Minelab SD2200, a friends Deepstar 2 PI detector by about 2 inches.

With the 10" coil, I could run the GT at 10 o'clock sens along with the Amp powered to maximum power...the machine in AM just purred along with a nice soft bubbling threshold. For the first time ever, I was able to to hit the 15" mark on an average 18k gold wedding band. I have never done this with any other machine before.

I don't want to get into the DISC/AM debate too much as it depends hugely on detecting environment.
The reason I use AM is for two reasons;
1. The Amp is a bit much for DISC
2. In DISC, the Sovereign (and Excalibur) will NULL on non ferrous items at fringe of detectability. I have walked over deep gold targets that have nulled....never again will I make this mistake.

Regards,
Tony.

 

[kered]

I think the only thing bad about the amp is its rarity, scarcer than hobbyhorses poo:veryangry:

 

[Tony]

I think the only thing bad about the amp is its rarity, scarcer than hobbyhorses poo:veryangry:

....I wish I'd bought two....

 

[plugger]

n/t

 

[dbsmokey]

Plugger,

How much were they new? What are they worth now?

 

[plugger]

n/t

 

[OldBeechnut]

Missed another, snooze you lose I guess...............Anyone else got one they want to part with?.................................I still got faith in ya CH..............how we looking..? Got that Baby figured out yet?..............
Goodmore............. How did your test go with the Amp and the s 12?.....thanks joe