For sale bare boards for Delta Pulse/Sniffer XR-71

[kt315]

And R5 (680ohm) is getting hot very quickly. No coil is connected.

--
no AC signal on GATE of MOSFET. MOSFET is always in OPEN state and getting hot very quickly. yes, you have burnt power lines to the CMOS.

[Loola]

KT315, you were so right, there was a burnt track under the 555, between pin 4 and 8. Now there is sound.
But now there is alot off it. It sounds like a toy machine-gun, with or without the coil and
it never stops. The only pots that make a change to the sound is GEB and T/Hold. They make the speed
off the sound increase. And there is no reaction to metal.


I will try to attache two videos showing this sound.
Delta Pulse 01 is with connected coil
Delta Pulse 02 is with no coil


I have changed the VT1, no noticeable change. The lines looks good.


I have to tell you that I am very glad that you take your time to support me.

[Loola]

Here is next video: Delta Pulse 02 is with n

o coil

[kt315]

nosense to twist the pots if board is not working. set o-scope probe in T3. set 100 Hz by PPS trimmer.
check pulse width changing by DEPTH pot, it is minimal value 150, maximal 500 us (MICRO seconds).

100 Hz is period 1/100 = 0.01 s = 10 ms (MILLI seconds)

[Loola]

T3 on scope

[kt315]

this diagramm is not in scale, but you have to get same signals. that is in relation to -E, ie your GND wire of o-scope probe is connected to MINUS of battery.
or after diodes VD8 VD9.

[Loola]

Sorry KT315, new try.
2 photos, one with Depth knob at min and one at max. Hard to see in picture but there is a small difference at the length of the short part.

[kt315]

normal standart reaction https://www.youtube.com/watch?v=geX1...ature=youtu.be

[kt315]

mosfet transistor is opened by positive signal. it is very small, in relation to period. period is 1/100 0.01 second, signal width is 0.000150 second. 150us.
you get strange impulse. desolder mosfet and look impulse on the mosfet's gate point again.

[surfdetector]

Hello KT,

Do you have any Delta Pulse boards for sale? Thanks.

[kt315]

set pots in those positions and never twist them.

8. Set pots in pre-set position:

- DEPTH - min, at left side, counter-clockwise
- DISC - min, at left, counter-clockwise
- GEB - middle
- SENS - middle
- T/HOLD - middle

I SAY NEVER TOUCH THE POTS -! IF YOU DO THAT YOU WILL GET VERY BIG TROUBLE.
i had (HAD) got the boards with problems of pots -!

[kt315]

Hello KT,

Do you have any Delta Pulse boards for sale? Thanks.

hello,

i will inform you as soon i receive new batch. thank you.

[Loola]

Yeah, I have seen this video earlier. And I have a Bulgarien XR-71. So I know what to expect.


Gain point at the Mosfet is the same as T3 when desoldered, and Drain is an inverted Gain when Mosfet is in place.


One thing I have noticed: The R5, with or without coil, is not getting hot any more???


"you get strange impulse" by that, do you meen that the scope do not show a continues string of measurements?
If so: It is the scope that causes this brake in the measured string.

[kt315]

do not set o-scope on drain. NEVER. you'll burn it. time to look on pics of your board.
i feel you do something wrong.

[Loola]

Yes, here it comes.