Delta Pulse - Take 2

[Sally]

T4 and T5.... i had met a problem in board i got in repair... that was abnormal working 4538.
let to see pics of T4 and T5 one-pulse-on-screen/one-period-on-o-scope.

I don't have enough time to fine tune time delay because we are on Holy week and it is holiday today and tomorrow in my country.
This is actual time delay on DP board. ,

[surfdetector]

I just check the time delay of T4 and the result is 8-32 micro seconds and T5 is 40-310 micro seconds. I am confused with the result
because the chart time delay that was posted here as a guide is T4=90-170 micro seconds and T5=160-900 micro seconds. Please let me know your thoughts.

Sally

Pulse Width OUT = RC (PW in seconds, R in Ohms, C in Farads)
Have you checked your component values?

[kt315]

T4 and T5.... i had met a problem in board i got in repair... that was abnormal working 4538.
let to see pics of T4 and T5 one-pulse-on-screen/one-period-on-o-scope.

[Sally]

perfecto amigo! now set TX POWER PULSE WIDTH to standart for DP (100-120) :: (450-500)us.
C3 and R4.

Okay, I will do it. Just solve also T4 and T5 delay. Thanks a lot.

[kt315]

perfecto amigo! now set TX POWER PULSE WIDTH to standart for DP (100-120) :: (450-500)us.
C3 and R4.

[Sally]

thx. looking as 'american standart' (postwar help of Big Brother). set sure 120Hz in point
T2 or T3.

Yes I did adjusted 100k trimmer with T2. Time is 8.3 millisecond = 120hz.

[Sally]

I cannot really see the wave form properly here. How did you choose the size of your damping resistor?

I used 680 ohms 1 watt resistor.

[surfdetector]

screen shot of DP T1 with search head connected. [ATTACH]57153[/ATTACH]

I cannot really see the wave form properly here. How did you choose the size of your damping resistor?

[kt315]

220v AC, 60hz frequency.

thx. looking as 'american standart' (postwar help of Big Brother). set sure 120Hz in point
T2 or T3.

[Sally]

again same question. what electric net standart frequency is in your country?

220v AC, 60hz frequency.

[kt315]

again same question. what electric net standart frequency is in your country?

[Sally]

screen shot of DP T1 with search head connected.

[Sally]

Yes, output of LF357. No search coil connected.

[surfdetector]

For Surfdetector, here is the screenshot.[ATTACH]57152[/ATTACH]

This is the output of the preamp? It does not look correct.

[Sally]

For Surfdetector, here is the screenshot.