No Response to Metals on Gary's Pulse 2

[Ajay0707]

Dear Gurus,

I have completed the construction of Garys Pulse 2 detector. Unfortunately I am not getting any response to any metal of any size on it. I have set the Receive, Dead and Width VR's recommended by Gary but there is no response and Gary says " there is no guarantee that this detector work with these settings, Play with it". I am not understanding where to start the trouble shoot. Please throw some light in my way...

-Ajay

[porkluvr]

What settings? Why not be specific... I don't know what Gary said to use. If you know, then why you not tell us?

But wait...
You constructed Pulse 2? Maybe you should think about getting up and running with the Pulse 1 instead. I seem to remember that Gary wrote that he himself had problems getting Pulse 2 working right. Dual coils are tricky.

Old saying: "Learn to walk before you run". Pulse 2 uses two coils and is tricky to get working, even for expert. Pulse 1 uses a single coil and that is what you should do.

[chemelec]

Pulse 2 uses two coils and is tricky to get working, even for expert. Pulse 1 uses a single coil and that is what you should do.

A Misconception: Both the Pulse-1 and the Pulse-2 can use Either Single or Dual Coils.

The Only Difference between these two Detectors is the Addition of the 3 Extra Controls.
And If they are not set correctly, the Detector may not work, or work very poorly.

[Ajay0707]

Hi Porkluvr,

Sorry for creating confusion and also for a late reply. I was actually talking about three extra controls(Variable resistors) as in Gary's website. My idea was to get help from someone if they had the same issue.

I actually constructed Pulse-I and its working really well. I just wanted to have more sensitivity on my detector... So, I made Pulse -II also. But unluckily I am stuck with this problem.

GARY with your kind permission... I am pasting your recommendations here..

R5A which is VR5, Set to a 10K Resistance. R7A which is VR6 Set to a 4K7 Resistance. R9A which is VR& Set to a 3K3 Resistance. The reason for this is it puts these setting about equivalant to the Pulse-1. And it will operate with almost any coil. Otherwise you may have the wrong settings for the coil your using. This May result in Not get any Response to metals.

[porkluvr]

Hi Porkluvr,

GARY with your kind permission... I am pasting your recommendations here..

R5A which is VR5, Set to a 10K Resistance. R7A which is VR6 Set to a 4K7 Resistance. R9A which is VR& Set to a 3K3 Resistance. The reason for this is it puts these setting about equivalant to the Pulse-1. And it will operate with almost any coil. Otherwise you may have the wrong settings for the coil your using. This May result in Not get any Response to metals.

Check your dead time circuit.

I think you've stated your potentiometer values (although I have never seen a 3k3 pot, like you've mentioned for VR& - or maybe you meant VR7) but that still leaves the question of what those associated fixed R values are. Which also leaves the question of what those Rtotal values are in the 555 circuits.

Check the total ranges of all the fixed R & pot combinations (total of R7+R7A etc. as you turn the potentiometers from minimum to maximum) and make sure that the ranges spanned between the min and max values includes the value of the fixed resistors that you used in the Pulse 1.

If those ranges are correct, make sure you have the correct timing capacitor values. If those are also correct, then you must consider that the problem may be something other than what is specific to the Pulse 2.

[Ajay0707]

Hi Porkluvr,

I have checked the fixed + variable resistor values they are same as Pulse 1 and now I think I have to check the Timing Capacitor values. I will check it and I will post my observations here. Many thanks for your valuable time.

-Ajay