Barracuda Legend Kit Problems

[Impulse]

ok i have CUT the link and put the 10k pot in its place

here

[Old cart]

KT 315 So there is about a 200 uS delay between the 2 strobes? You did not state the time per div and volt per div.
Thanks for you help!

[Old cart]

You do not see THE DELAY between THE signals (the samples' strobes).

KT I think the problem is those strobes are not being fed the right signal from U4 f, the signals are too small to properly toggle the Schmidt inverters so what you seeing is just a pulse on the rising and falling edge of the transmit signal due to crosstalk. Since this is synchronous with the transmitter there is no delay between the signals. The 40106 has a hysteresis of .9 volt with a 5 volt supply so it will not respond to voltage below that. In this circuit there is a lot of crosstalk, that part if the design looks less than optimum.

[Old cart]

ahh now i know what you mean sorry i thought i was missing something, yep no delay between the signals. I have looked at post 210 and all the components are in the correct place. i have a spare 10k pot i can put across the external delay pot connections?

The problem is with the delay generator U4f, c5 and r10. Something is wrong there. I think the signals pin 2,4 of 40106 have no delay between them because the signal getting to them is too small, it is just a spurious signal that is actually coming from crosstalk between the transmit pulse generator U4 d and e and the imput to the delay u4 f. I thin if we fix the underline part above the circuit will work.
The 10K pot you have will work great, just set it for max resistance between the center pin and the left pin as viewed with the pins facing down. If you get this correct clockwise rotation of the pot should increase the resistance and the delay. This is the OPPOSITE of the trimmer where clockwise rotation decrease the delay which is illogical and confusing. Then cut the delay pot Link on the board with a sharp knife a measure between the two PCB pads to ensure you have cut it. Lastly solder the two wire from the 10 k external pot. And take traces at pins 2 and 4.
Make sure you are clear what trace ( Link) to cut before doing it. Ask if this is not clear.

[Impulse]

i have a spare 10k pot i can put across the external delay pot connections?

good/bad idea?

[Old cart]

5534 pin6 [ATTACH]35412[/ATTACH]

That looks OK but over damped. It is 20-30% better than what you had with the longer cable. This means the damping resistor is too small of a value. We will deal with that later.

Please remind me later.

[Impulse]

ahh now i know what you mean sorry i thought i was missing something, yep no delay between the signals. I have looked at post 210 and all the components are in the correct place. i have a spare 10k pot i can put across the external delay pot connections?

[kt315]

a delay making? next to cap 4 and resistor 17? what am i not seing?

you do not see THE DELAY between THE signals (the samples' strobes).

[kt315]

both now

http://storage8.static.itmages.ru/i/16/0305/h_1457208032_1278190_4509ca53a7.jpg

[Impulse]

you do not have a delay making by C4 R17 (U4 12-13pins). bad you do not see that.

a delay making? next to cap 4 and resistor 17? what am i not seing?

[Impulse]

5534 pin6

[kt315]

kt315 yer they are the same no matter the position of the delay trim it does not change only the amplitude

you do not have a delay making by C4 R17 (U4 12-13pins). bad you do not see that.

[Old cart]

Impulse see you got your PC fixed. Good job. As KT 315 says these signals appear to be the same, pin 4 should be significantly delayed relative to pin 2. The pulses should also be about 4V high and 45 uS wide. See post 205. Your signals just show the spurious response which is apparently (but not desirable) for a Barracuda. See the first two pics for what it should look like.mthe pic delay -near- minimum shows what you have which is wrong. I would do two things
1. Look at post 210 and very carefully compare you board to the pics Ray so kindly provide. If you do not see any differences do 2.
2. Cut the link across the external delay pot connections and install a 10K ohm fixed resistor.
The
There is something wrong with this sample pulse generator and unless it is working correctly the detector wil work very poorly or not at all. Until we get this fixed we can not proceed. It is my hope this is the last remaining problem. The rest is just tweaks

BTW I forget can you get you old board to work? Also can you send a 5534 pin 6 trace of you new board with the shorter cable?

[Impulse]

kt315 yer they are the same no matter the position of the delay trim it does not change only the amplitude

[kt315]

40106 pin2 and pin4 is same - 45us has to be