King Cobra PCB

[growdude]

Cobra pcb

Hows the cobra pcb layout coming along.?

[kt315]

thanks again. can anyone give a logo King Cobra in good quality at PCB more than this I did?

[WM6]

ups. thanks! it is a limiter of ALL-METAL circuit reply, as far as I catch it.

It is about filtering (cut) out strongest signal (usually signals from targets near to surface) in comparison with a threshold setting level.
If you raise the coil, the surface blanking effect disappears. Unwanted side-effect: you ca lost signal of bigger deeper targets too.
Very nice option in coin shooting at some terrains.

[kt315]

ups. thanks! it is a limiter of ALL-METAL circuit reply, as far as I catch it.

[WM6]

Surface blanking - detector will not detect items until adjustable depth-usually 1 to 5-6 sm from the surface.

Or in drawing:

[Pompey]

Surface blanking - detector will not detect items until adjustable depth-usually 1 to 5-6 sm from the surface.

[kt315]

this is part of Tesoro Royal Sabre schematic. any thoughts what do a trigger and a pot SURFACE BLANKING? can anybody give a clipping from its manual with a mention of the tuning?

[kt315]

Hi;

These are still the same patterns slow filters - virtually the same as the Tesoro, identical solutions of discrimination. At the moment we are thinking rather of digital processing of the ADC - think about such solutions. In the era of ARM devices are only historical. You need to think differently - otherwise this forum is not the ears in the direction of modernity.

Regards
Taktyk

hello Taktyk, if you are russian so you have to be in course of all DIGITAL projects that people make and made. I do not see your profile - who are you? what is your native? what country and city you are living in?can you give direct link on your digital project? is it FREE and ASM code will be fully free from charge for any one? I ask because 'digital' ones I see around are ONLY commercialized, nobody wishes to give you ASM code and even HEX. people constantly asked me in PM to give them ASM code on CLONE-PI, STALKER etc. for example. and i did answer only - I am not in this field.

[Taktyk]

Hi;

These are still the same patterns slow filters - virtually the same as the Tesoro, identical solutions of discrimination. At the moment we are thinking rather of digital processing of the ADC - think about such solutions. In the era of ARM devices are only historical. You need to think differently - otherwise this forum is not the ears in the direction of modernity.

Regards
Taktyk

[kt315]

IC's were been renumbered

[Merc]

Some notes I made while trying to repair a 4" GMT coil. I had to compare phases and amplitudes to a working 8" coil. I finally got it right using my 2 channel scope in Lissagous pattern mode, X-Y. TX signal on one input and receive on the other and set my gains to get me a nice oval in the middle of the screen. Then all I had to do was null until i got the same shape oval on the 4" that I had on the 8" coil.


King Cobra 8" coil.

Pins 1-4 22.6 ohm, 6.04mH
Pins 2-3 22.8 ohm, 6.06mH

14.53KHz

When properly nulled, pin6 of the receive amp(LM30 should be 300-350mV p-p and should lag TX by 44uS..

[growdude]

Faceplates and housings look good

They are nice just like a king cobra and he has a few that are drilled and a few with blank faceplate box mounting hardware also for 20$each its a pretty good deal I got some for my KC project and my GMT 1650 project .

[Merc]

I have thought about getting those same housings and shafts from Keith. How do they look? Is there a faceplate with the housing? Pre-drilled.

Merc

[growdude]

Thanks Merc

I was entering the letters and numbers from the chips on my original KC board and wasn't getting anything.I'm still new and learning almost done with my igsl and my tgsl I'm gathering parts for my KC project.got a few of the original KC housings and shafts from Keith Wills.thanks again.

[Merc]

Digikey has ICL7660CPA-ND for 1.61 in quantites of 1. Also LF442CN-ND for $1.37 in quantities of 1.