CS6Pi

[headshed22]

Hi to all,
After following the forums as a 'guest' for some time now with a rekindled interest in both metal detecting and electronics from my youth, the Early 80's when I built my first metal detector. (eti 549) I thought it about time I bought myself a Pi machine, joined the forum. and started experimenting and playing about.

So off I went to the good old on-line auction site and bought myself a C.scope CS6Pi. Before playing around with it and trying some modifications etc. I knew it would be a good idea to get used to the machine and its capabilities as it was designed beforehand, However I am having some difficulty in setting the threshold, being very 'jumpy' as if the track on the potentiometer is faulty although this checks out fine. the meter is very erratic also, all solder joints appear fine and the co-ax and coil are in good order giving a constant and correct resistance reading within limits as seen from previous posts in the forum.

The detector does however appear to have been previously opened and there are minimal signs that the two trimmer pots have been adjusted.
Does anyone on the forum have any data on the setup procedure, or any modifications, home made coils etc that they would be willing to share with me in regards to this machine or any other C.scope detector for that matter as I wish to persue with this make for the time being.

Thanks all in advance.

Regards,

Russ.

 

[Chips]

I realize your post was written some time ago, but I was wondering if you solved your problem with the cs6 p.i..Im interested because ive just bought one off e-bay and im going out with it tomorrow for the first time, so if you persevered with it i thought you might be able to give me some info as regards what sort of depths ill get, what you thought of itin general as a detector etc. Ive done air tests with it and they seem pretty good but will they be as good on the beach , appreciate any help.

 

[sand turner]

I realize your post was written some time ago, but I was wondering if you solved your problem with the cs6 p.i..Im interested because ive just bought one off e-bay and im going out with it tomorrow for the first time, so if you persevered with it i thought you might be able to give me some info as regards what sort of depths ill get, what you thought of itin general as a detector etc. Ive done air tests with it and they seem pretty good but will they be as good on the beach , appreciate any help.

I've got a CS4pi. Electrically I think they're very similar (but I don't know for certain) mine has an LED instead of a meter. Threshold's not great on that. It's never going to be as smooth as a VLF but you just got to play with it nick the PPS down a fraction, keep giving the threshold knob a very small tweak etc. Generally, I think you've just got to accept it's going to be less "refined" than a VLF threshold.

I was running mine just below a threshold and about 4100PPS.

Now I'm running it flat out and with a threshold that is audible, but you have to listen VERY hard to hear it and it does fluctuate in and out from audible to inaudible if you see what I mean. You get alot of chirps and ticks that way but good targets WILL break through this and you need the confidence that this IS going to happen. Hours on/and finds with the machine will give you that. Only thing's I'm not happy with are lack of a gain control and the SLOW SAT.

Overall I'm very pleased with mine, although I'm leaning towards buying a Surfmaster (purple box) simply as it looks like you can get a better threshold with that and it has an internal gain control plus fast sat. Yes, I know it isn't as responsive as other Pi's to "smaller gold" but I'm not that interested in "smaller gold" anyway.

 

[Reg]

Hi Chips,

I suspect there was nothing wrong with Russ' CS 6. PI's are really bad about having a noisy threshold, especially if they are tried in town or close to any electrical equipment. So, one shouldn't try to compare a PI with a VLF when checking the threshold stability.

Now, one way to sort of tell as to whether the noise is coming from an external source is to adjust the frequency control. If the noise changes as a result of adjusting this control, then the noise is some form of external noise that is causing the problem. This control also adjusts the delay so for maximum depth one shouldn't adjust it much to reduce the noise. In other words, usually it takes just a very minor tweak of the control to improve the stability so one shouldn't adjust the control any more than that if they want maximum depth capabilities for gold objects such as rings.

I wish I would have noticed Russ' post back when he posted it. However, I can't do anything about that now. I can say that one doesn't want to try to adjust the internal controls on the CS 6 without full knowledge of what they do and why. One of the controls requires a good scope to set the "0" voltage reference and the other is to minimize certain signals. Neither will enhance the depth of sensitivity but could cause a depth loss if adjusted incorrectly.

In simple terms any tweaking of the internal controls away from factory settings can only result in depth loss. Also, returning to the factory settings requires specialized equipment to get it right.

Here is a link to the C Scope website and their archive section. One can download the manual complete with operator adjustment info in PDF format from this site.

http://www.csmetaldetectors.com/archive.aspx

Reg

 

[Chips]

Ive been out a couple of times now with my cs6 , found a few coins but no rings so far, but theres something i dont understand. I often get signals, strong ones that when dug turn out to be nothing at all. I dig the target, seperate the piles of sand until ive isolated it down to the smallest pile then sifted through that only to find absolutely nothing even though the signal is still there. If it was only once or twice id assume id just missed the target, but it happens too often for that and i search very thoroughly. What am i doing wrong ?. is it a settings problem? is the detector so sensitive that its picking up things invisible to the human eye?( no way). Is it something common to early p.i.s. or am i doing something wrong. Help please

 

[sand turner]

Some of the stuff is very small. I find upholstery staples and the like. They're extremely hard to locate. A large loudspeaker magnet is my probe for the beach if you're curious

 

[Chips]

The magnet is a good idea, never thought of that, but it wouldnt pick up those small blobs of melted aluminium though, and some of those look just like small pebbles, so i must be missing them i suppose.Would a pinpoint probe help, or would that be affected by the salt ?. Thanks for the reply

 

[Reg]

Hi Chips,

There are different techniques that are used to find small objects. The magnet is a good idea and is used a lot by nugget hunters who spend a lot of time looking for very small targets. The most common magnet to be used is a very strong super magnet attached to a rod, digging tool or other convenient object.

Next, many nugget hunters will use a small plastic scoop and pick up a little of the dirt in the scoop and pass it over the coil. If a person is lucky, they will pick up the object in a scoop or two and then it is a matter of sifting through the sand in the scoop. One way this is done is to lay the detector down, pour a little of the dirt or sand from the scoop into your other hand or on to some cloth and check the scoop for signals again. This is done until the signal is finally in the hand and not in the scoop. Then the object and sand is poured back into the empty scoop and searched again, or the process of separating out the sand in smaller quantities until the object is found.

Here is a link to a typical plastic scoop used for the purpose I mentioned.

http://cgi.ebay.com/plastic-TREASURE-SCOOP-shovel-metal-detecting-trowel_W0QQitemZ150379481432QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item230350c958

Actually, any simple plastic trowel type digging tool should work.

Reg

 

[sand turner]

I've got one of the scanmaster type handheld probes and it's ok. BUT even wrapped in foil tape it does interfere with my pi even when I've just got it in the pocket of my coat rather like my mobile phone which I now leave in the car. Seems pi's are even more sensitive to interference than VLF I don't know about the 6pi that could be ok but I doubt it will be any different .

 

[Chips]

Thanks for the info , all good tips

 

[bbsailor]

Ive been out a couple of times now with my cs6 , found a few coins but no rings so far, but theres something i dont understand. I often get signals, strong ones that when dug turn out to be nothing at all. I dig the target, seperate the piles of sand until ive isolated it down to the smallest pile then sifted through that only to find absolutely nothing even though the signal is still there. If it was only once or twice id assume id just missed the target, but it happens too often for that and i search very thoroughly. What am i doing wrong ?. is it a settings problem? is the detector so sensitive that its picking up things invisible to the human eye?( no way). Is it something common to early p.i.s. or am i doing something wrong. Help please

Chips,

Here is a tip that will make you a very efficient beach hunter. I use this every time I hit the New Jersey Shore.

Obtain 0.5" galvanized wire mesh.
Obtain or make a 12" diameter plastic ring using 0.5" to 0.75" (OD) flexible tubing. Use a wood dowel to join the ends together.
Make a wire mesh basket that is 12" tall and 12" in diameter. Do this by interlocking the wire mesh ends with an angles needle nose pliars. Do the same with the bottom. Make it so that a dime will not fall through any joints. Wrap the top of the mesh around the plastic tubing. Make the inital height cut about 13.5" tall to account for the wrapping over the tubing. The tubing serves to keep the top of the mesh bucket open and provides a place to secure a 4 foot rope handle. Tie a 4 foot piece of rope to the center of the rope handle with a coat hanger "S" hook on the end. Clip this "S" hook to the bottom of the mesh basket so you can carry the basket over your shoulder. You can also drag it behind you to leave a track of where you have detected. Use a long wood handle shovel to retrieve your targets.

It works like this.

When a target is detected, place the basket on the ground nearby. Use the shovel to dig the target out of the sand and place it on the side of the hole. Scan this pile for the target. You will get better as you practice. Once the target is out of the hole, just scoop it up with the sovel and deposit it in the basket. I usually fill my basket with about 10 targets before I shake the basket to retieve them. From the time I locate the target in the sand until I scoop it up with the shovel, it is about 15 seconds. When you find a hot spot, you will thank me for this tip. It is very efficient.

I use as bunge cord (double 1/8" diameter) and a custom loop supported from the center of my belt in the back. I use a looped sail tie (1" web strap) through the belt loop and about an 18" loop on the other end that I flip over my head resting on my shoulders so the weight is not on the back or my neck but on my belt. I attach the bunge chord to the front of the 18" loop located about 6" under my chin using a quick disconnect plastic hook (available at boat stores). Then I secure the other end of the bunge cord to the metal detector shaft near the control housing. Adjust for the most comfortable support of the detector weight and your arm's weight. Guide and glide the coil over the sand using this assembly. You can hunt all day without getting tired.

When you find a target you will need two free hands to use the shovel so just let go of the detector; it is supported by the bunge chord and now you can quickly retrieve your target.

This is a custom device that I invented. There are no commercial mesh baskets that I know of. Make one. They last a long time if you wash off the wet sand and salt water each time you use it.

If the CS6PI has too low of an audio level for you, that is because there is a few hundred ohm resistor in series with the headphone. Open the battery compartment and tack solder about a 47 to 50 ohm resistor in parallel with this resistor. Doing this will increase the audio level. Try to use a headphone that blocks out the ambient noise of the waves breaking and sea gulls.

Learn how to listen for the double beep when going over ferrous targets and rusted wire shards.

Go out hunting about 3 hours before low tide and when the wind is pushing the waves out from shore. The best gold stuff is in the wet sand. Hunt after bad, windy weather, nor'easters and heavy beach erosion.

I hope this helps?

bbsailor

 

[Chips]

Thanks for all the tips , i like the wire basket idea and ill give it a try, the audio level is fine and im sure ill get better as i go on , especially after i find my first gold ring. The beaches here in the U.K. are pretty small compared to yours and theres lots of competition so it may take a while but tips like yours help a lot. Ive just ordered a probe as well and got a pretty good magnet so that should help with my 'invisible' targets. Do you use a p.i. sailor or something else?.

 

[headshed22]

Hi all, Just returned and noticed this post again,
Yes I did manage to repair my 6Pi. There was a bad track on the threshold control pot that was replaced, this is what gave the 'major' threshold variation that I was talking about in my original post.
Also it was obvious that a previous owner had played around with the internal trimmers. They were both a bit mangled so I replaced both components with new ones. After months of searching the forums for some form of set-up procedure without any replies, I managed to obtain another unit for comparison.
Connecting the good unit up to the oscilloscope enabled me to compare and match the traces of each machine, The repaired 6Pi now gives an almost identical performance to the other unit. I find the CS6Pi a very good machine to use.
I have also made some smaller 5" and 8" coils for it and find the 8" particularly useful on the beach due to the slightly increased sensitivity to the smaller targets. The 5" is an amazing little coil in the right locations.

I have also bought a CS4Pi and although it is much more similar to the CS7 being controlled by a PIC16 processor, the two units are very similar and appear to be based on Eric's famous Beachscan design.

I really wish that i could obtain the standard setup procedure for any of these machines as i am playing about with some modifications of them all.

Any chance Sir Eric ????

 

[Chips]

Glad you repaired your 6.pi. After having a bit more experience of using it now i am getting to like it a lot, i usually dig everything anyway so no discrimination doesnt really matter to me , i even use it in the dry sand and i find there is a slight variation in some of the signals, length of signal compared to width, double beep on iron for instance, that allows a rough indication of whats there. And for the money, its very good. In fact it goes so deep at times that if i dont find the target in the first ten inches i give up.Good Hunting.

 

[Reg]

Hi Headshed,

The CS 6PI I have only has two internal controls. I mention this because someone mentioned there were some CS 6PI's with three internal controls.

I have no idea what the third internal control would be doing.

The two internal controls I have are one near the preamp IC, the 709 and the other is on the opposite side of the board, RV 2 I think.

The one near the preamp is there to adjust the output of the LM709 to "0V" once the signal has decayed. This should be set up with a scope looking at the output of the 709. There is a test point available for that purpose.

The second pot is to adjust the point at which the negative half of the signal out of U 4b is ignored. Adjust the control for basically 0V out of that amp also. At that adjustment, the negative voltage exceeds about 2 mv, the amp input is shorted with a FET. This also eliminates the negative half of the signal when a target is heard, thus making the detector recover fast enough to hear a second target very quickly after the first.

With the autotune feature, this adjustment is not nearly as critical as it was on earlier designs.

Reg

 

[headshed22]

Hi again all,
Chips, yes I also find the CS6Pi a great detector to use. A great bullet-proof, solid and stable design by Eric.
Unfortunately I don't do as much detecting as I would like to these days, just the odd day now and again so I spend most of my time playing with metal detectors on the workbench.
I hope to change that soon and spend a lot more time 'out in the field' so to speak.

Reg,
My most sincere thanks to you indeed.
Most of the 6Pi units I have seen (including mine) have only the two trimmers, I have only seen one photograph of a unit with three, I think it was over on the geotech forum.
That is exactly the information I have been looking for. It is one thing to just copy settings and measurements from one unit to another. but to get an understanding of what is actually going on needs an explanation like you have just given.
Being by no means an electronics engineer, but a simple hobbyist with a quest for knowledge, I can and do however, follow and understand most of the technical issues raised on the forum.

That is a great explanation of the adjustment to the output of the 'TL062' U4b.

Again many thanks Reg,

Russ.

 

[Draco]

http://www.geotech1.com/forums/showthread.php?t=14750&highlight=cs6+pi

Hi, this detector was, here I leave the link. Greetings