The Crossbow Classic PI

[keith777]

i could see my photos yesterday when i made the post. some how they are not showing now. never mind i will re-post again.

[kt315]

are my pictures not showing or something like that.

english is not my native K777. why i can that you can't... all around you here in english...
you are in YOUR native environment here... i do not have to learn you.

[Qiaozhi]

are my pictures not showing or something like that.

They're not showing. You've probably linked them to images on your own computer, which no-one else can see.
See post #31 for details of how to upload pictures to the forum.

[keith777]

unreadable pics K777.

are my pictures not showing or something like that.

[Qiaozhi]

If I do consider a mono coil, do I check that it has a specification of: Inductance 500uH and Resistance 2ohms with a built in damping resistor? I guess that the connections inside its 5 pin connector (if it has one of 5 pin) will have to be altered as per previous info’ provided by George?

The original 10" diameter coils have a built-in damping resistor, but commercial coils will have this resistor located externally. You can also use these coils on the CCPI by adding a suitable resistor inside the enclosure at the back of the coil connector socket. The socket should have 5 pins, but only 3 of these are in use. Pin 1 is TX, and pin5 is RX. The shield (0V) is connected to pin 3. This means that pins 2 and 4 are available. For a mono coil (like the standard one) pins 1 and 5 are connected together, and the shield goes to pin 3. For the Garrett Seahunter coils, I put the resistor across pins 2 and 4, and then (in the coil plug) jumpered pin 3 to pin 4, and pin 2 to pin 1, with pins 1 and 2 shorted together, and the shield connected to pin 3. Alternatively you could provide the facility for the two different values of damping resistor, by connecting one resistor between pins 2 and 3, and the other between pins 4 and 3. Then add jumpers in the coil plug as appropriate. I haven't tried using a Minelab coil, but I believe the coil plug is the same as the CCPI, and may even have the same wiring. Although you'll have to check that yourself.

For a coil with separate TX and RX windings, you must not short pins 2 and 4 together (obviously).

I have seen drawings comparing the signal shape in the ground between the two types of coil, will the shape remain the same with a DD coil on a PI machine?

Yes.

I note that DD coils seem to be made for individual detectors, e.g. a coil for a Minelab Sovereign wont work on a Minelab Explorer. So how do I find a DD coil for the Crossbow? What specifications do I need to find or ask a manufacturer for?

The inductance can be between 300uH and 500uH. The coil resistance is not that important.
If you post details of the coils you're considering, I'll can let you know if it will work.

Will the 5 pin connector connections need to be altered?

Yes - see above.

Oh, almost forgot….How do I tell when it is fully charged?
Thank you.

Just charge it for the recommended time. The built-in charger is current limited, and it will go into trickle-charge mode once the batteries are charged. I've left them on charge overnight without any problems.

[Qiaozhi]

this was my crossbow before i put it on to a straight shaft.

Click on Reply, then click on Go Advanced.
Scroll down to where it says Manage Attachments.

[homefire]

NiCad should be charged when they are up to or just over the rated 1.2V and pulling less then the C-10 Rate. 1/10th the Capacity Rating.

Same with NiMH

Li Ion charged on Reaching 4.2 Volts.

[kt315]

unreadable pics K777.

[keith777]

this was my crossbow before i put it on to a straight shaft.

[TowySalmon]

12 x rechargeable(white in colour) Eneloop AA, but I didn't look to see what mAh they are.

[homefire]

""Oh, almost forgot….How do I tell when it is fully charged?""

What kind of batteries are they ?

[TowySalmon]

The Crossbow arrived yesterday and I spent a few hours mounting the control box on a straight length of carbon fibre at the top end. The top 4” had been strengthened with car body filler with added fibres prior to drilling for the two bolts. Below this I put an arm cuff (not the one that came with machine) and below this a handle. I used the original middle and bottom section of the shaft. It balances wonderfully.

I spent 3 hours on the beach with it today. I kept thinking of how teeny the coil looked (I have used a 15” coil on another detector for past 9 years almost exclusively). I have used PIs in the past and I soon got into using the Crossbow.

Please excuse my lack of knowledge but I do have some thoughts and questions and I would be grateful for any comments and/or suggestions in return.

I feel that I need to be using a bigger coil in order to cover more ground. I think that this would be a DD coil as less overlapping in the sweep is required compared to a mono coil(?).

I did look at Minelabs specification charts of coils. What struck me about the mono coils was that they are water resistant and not waterproof; so they’re not to be considered.

If I do consider a mono coil, do I check that it has a specification of: Inductance 500uH and Resistance 2ohms with a built in damping resistor? I guess that the connections inside its 5 pin connector (if it has one of 5 pin) will have to be altered as per previous info’ provided by George?

I have seen drawings comparing the signal shape in the ground between the two types of coil, will the shape remain the same with a DD coil on a PI machine? I note that DD coils seem to be made for individual detectors, e.g. a coil for a Minelab Sovereign wont work on a Minelab Explorer. So how do I find a DD coil for the Crossbow? What specifications do I need to find or ask a manufacturer for? Will the 5 pin connector connections need to be altered?

I appreciate that DD coil may not be as deep as the same size of mono coil, but I just have a gut feeling that I would be happier with say a 15” to 18” DD, oh and round, not ellipse.

Sorry for the lengthy post.
I am thrilled though to be a very proud owner of this machine. I want to get the best out of it for me. I am hoping it will give me years of enjoyment.

Oh, almost forgot….How do I tell when it is fully charged?
Thank you.

[Qiaozhi]

do you have a link for the video.......

You can find a few videos of the CCPI by searching for "crossbow classic pi metal detector" in youtube. The 18" coil video is a bit disappointing, as it doesn't even show the coil.
There used to be a good video of someone using a CCPI on a beach in Ireland, but it seems to have vanished.

[keith777]

There's a video on youtube showing the CCPI with an 18" diameter Detech coil. That's the largest I know about.

do you have a link for the video.......

[Qiaozhi]

whats the biggest coil out there that has been used on the crossbow.

There's a video on youtube showing the CCPI with an 18" diameter Detech coil. That's the largest I know about.