What I hate about the PI Dual... And it isnt iron or bobby pins...

[Silver Surfer]

I have used the PI Dual for a few weeks now, and although no one exaggerated the digging iron thing one bit, I dont really have a problem with that... The depth is crazy, and makes one HAVE to read and learn or a few hour hunt turns into a nightmare of "holes to china" for a rusted hook or sliver of iron.... I do wish that they made it a multi-tone machine (if that is possible for a PI) but the thing I am beginning to hate about this machine is this...
UNSTABLE THRESHOLD IN SURF!!!!!!

No matter how high or low I set the gain, this damn machine insists on- Loud as hell with an incoming wave, then silent with the undertow, then loud as hell again with the next incoming wave... I thought it was me, or that I had a glitchy machine, but my buddy Dave says his does the same thing...

Yesterday drove me absolutely nuts trying to maintain a somewhat stable "hum"..... Couldnt do it... I even tried facing the surf and swinging side to side... It seems to be the depth of the water changing..

If any of you have a Surfmaster or PI Dual and have figured out a way to at least minimize this huge swing in threshold, or simply to say "better get used to it", please chime in...
I love the feel of this machine, and like I said, the depth is crazy.... But dayum, I would like to get at least some kind of stable threshold in the surf.... Freshwater lakes, even with good sized wind waves, is perfectly stable.... So it has to be a salt issue..

HH

 

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[Carl-NC]

Do you have the one with the variable pulse delay? If so, turn it up slightly until it no longer responds to salt. The min delay on the SMPI is 15us, which is very close to where salt responds. Keep in mind that increasing the delay also reduces sensitivity to small gold so if you are not in the surf then keep the delay at the min setting.

- Carl

 

[Silver Surfer]

I will have to try that, and thanks for that info.... I was going to try that in a last desperate attempt, but everything I read, and other I talked to, said "dont increase the pulse delay, dont increase the pulse delay" so I didnt.... I really appreciate the advice and will surely post my experience doing that..

 

[Seaweednh]

I will have to try that, and thanks for that info.... I was going to try that in a last desperate attempt, but everything I read, and other I talked to, said "dont increase the pulse delay, dont increase the pulse delay" so I didnt.... I really appreciate the advice and will surely post my experience doing that..

Pick up a copy of Clives book on Pulse Power dedicated to this machine. It deals with this and other problems/settings.

 

[Silver Surfer]

I already bought it and read most of it... It talked about instability and the pulse delay, but it didnt really get into specifics like what I was experiencing, like the waxing and waning of threshold with every wave..
I thought it was talking about falsing and "static" like I get with my Excal or MXT when running them hot...
Like I said, broken or scratchy threshold, or even threshold being unstable in shallow water with breaking surf I understand.. I just couldnt figure out why in 4-5 ft of water, the swells/surf would cause that silent/loud/silent problem.... PI is a whole different critter... I will try increasing the pulse delay next time (even though my buddy who finds a lot swears I should never touch that dial)...
Thanks again..

 

[Seaweednh]

I already bought it and read most of it... It talked about instability and the pulse delay, but it didnt really get into specifics like what I was experiencing, like the waxing and waning of threshold with every wave..
I thought it was talking about falsing and "static" like I get with my Excal or MXT when running them hot...
Like I said, broken or scratchy threshold, or even threshold being unstable in shallow water with breaking surf I understand.. I just couldnt figure out why in 4-5 ft of water, the swells/surf would cause that silent/loud/silent problem.... PI is a whole different critter... I will try increasing the pulse delay next time (even though my buddy who finds a lot swears I should never touch that dial)...
Thanks again..

Did you get a copy of The White's Surfmaster PI Dual Field "Advanced Guide" Clive does go into detail on this but personally I haven't been in the water with mine yet. Still prefer the Excalibur

 

[Silver Surfer]

Not yet.... Money too tight right now.... But I plan on it...
Thanks for your tip, plan on trying it out this weekend...

BTW, what depth difference have you found if you increase the pulse width? Miniscule I hope..

 

[S.S.Tupperware]

Just bump in the delay... if you don't get too crazy, then no problem... I usually run mine with a lil delay to smooth out the thold. If its not running smooth you are losing depth anyway...

 

[Detector Wars]

I have done much research on this.

This problem of yours applies to all PI water units it seems, in mineralised salt water. It's not just a Dual Field thing.

I get this with my Infinium, it took me a while for me to get to the bottom of this.

The salt water you're detecting is mineralised enough to cause noises. These are bits of mineralisation float in the water moving up and down as the waves move up and down. They are also lower on the conductivity scale than iron, just below, but en-mass, they cause a lot of noise, given you have a large body of water around you (over your coil) and your coil picks up signals above it as well.

Also read this post, where I got a lot of information from: http://www.findmall.com/read.php?31,...40#msg-1237040

This seems to be the case for all PI's according to research, but I can only speak for the Infinium. It does not seem to cause noise to VLF water detectors. When I had an Excalibur 2, it was quiet in the water, but the performance decreased (I could also hear the threshold change, both the threshold and signals became duller). Even though the Excalibur was quieter, I was still going deeper with a noisy Infinium and getting more targets. However, I never compared them side by side, but I was consistently doing better in the water with the Infinium. bare in mind, these areas I hunted only had moderate amounts of junk.

The other bit of important information regarding this came from Oldbeechnut: http://metaldetectingforum.com/showt...light=infinium

Here's what you do:

1) Find a website that shows the wind speed and wind direction for the beaches that you're detecting. You want off shore winds or very little winds at all if they're not off shore. Choose those days to hunt, as the waters will be calmer. That way you might not have to detect with any pulse delay at all or maybe a little!

2) Depending on how noisy the water is, turn the pulse delay up, but not too high. On the Infinium, the pulse delay is called "discrimination", but that is false advertising. On the sand shark it's called pulse width. The DF has one also. Don't turn it too high otherwise you will loose too much depth. Turn it too low and it might be too noisy that you'll loose targets.

 

[Sandman]

Detector Wars nailed it! My Surf Pi Pro would do what your Dual Field does in the surf and increasing the delay a might is like dialing in disc. Some depth was lost, but I could hear the targets better as they were solid hits.

 

[Bromly]

I think your DF is like the one I had. I used it for 3 days and could not get a stable T-hold. I sent it back and the tek called me to confirm that there was a problem with the unit.

 

[Keppy]

I think your DF is like the one I had. I used it for 3 days and could not get a stable T-hold. I sent it back and the tek called me to confirm that there was a problem with the unit.

I agree with Bromly it should be sent back for a check up.......... I don't think it is your set up.