TP4 waveform wrong?

[Reg]

Hi Exciter,

Did you check the pot value also? Next, you want to check the voltage at TP 9 when you adjust R 31 from maximum to minimum and note the voltage. It should go from a - V to a +V. The voltages should be small, maybe .4v and -1.2V or so at the extremes.

Let us know what you have for voltages.

If the voltages are correct, double check your transistors, Q5, Q6, and Q11 to make sure they are correct and mounted in correctly.

Finally, check the values of R 38 and R 51 to make sure they are correct.

Let us know what you find.

Reg

[exciter]

Hi Reg,
i checked R30 and R32. 150K and 100K, also the solder points. IC8 pin 5 is zero volt.
I recorded the sound http://www.ewetel.net/~bernd.hille/hammer/HH.mp3
I turned threshold from maximum to next. But i cant get silence...
This was without a coil connected. But with coil its the same...

[Reg]

Hi exciter,

Your tp 4 is correct and Carl's is not. If you change your sweep speed it will look more like Carl's except for where your signal goes positive. It is supposed to go positive like yours does.

The audio on all the time is more likely a problem with one of the resistor values being incorrect around the threshold control. You might want to check them to see if you don't have an incorrect value for R 30 or R 32. Also, check to see if the soldering is good around C 19 and C 19 is good.

Make sure the autotrack switch is closed and the voltage at pin 5 on IC 8b is 0V. with a digital meter. If it is not, then C 19 may be bad or you may have a solder problem shorting it.

Let us know what you find.

Reg

[exciter]

Hi,
after i figured out, that i soldered a 10ohm instead of 1ohm for R10, i have the next problem.
after i calibrate IC6 for 0V with R18, my threshold pot. isnt working correctly...
i can´t tune it for silence. my HH just beeps around ( with and without coil).
My Coil: 25cm diameter 26turns 0,5mm coppper shielded wire.
I measured 2,4Ohm for the Coil. Maybe its to low? My flyback voltage is around 300V.
I compared Carl Scope-Pictures at TP4 with my and they look different.
I mean it works, but poor and there is the problem with the threshold.
I have the Option2 non VCO HH.
I use a 10,8V LiON battery. With 13,8V Power supply its the same. Also outside.


here a pictures of TP4 and flyback: