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adjustable capacitor C5 and C8 replacment

Posted: Fri Oct 13, 2017 4:54 pm
by stromar

i have performed signal generator test in step 3. And i cudnt get the wright wawe form. Then i loked at condensers d5 and d8 and they are some how defect.

Can sombody tell me where can i buy new one?


Re: adjustable capacitor C5 and C8 replacment

Posted: Sun Oct 15, 2017 1:16 am
by MNTech
It is important that those capacitors are installed as shown in the picture in the assembly manual with the beveled end of the part matching the bevel in the silkscreen. When properly installed the rotor of the capacitor will be connected to ground. Your screwdriver touches the rotor when you are adjusting. If the capacitor is backwards the screwdriver will be connected the input circuit and interfere with the adjustment.

Re: adjustable capacitor C5 and C8 replacment

Posted: Mon Oct 16, 2017 8:39 am
by stromar
if i undestand corectly. On the pcb board is white box in witch variable capacitor must be placed in corect direction. On one side there is squere on the other edgesof the squere are cut. i understand this. Thanks. This capacitors are alredy on the pcb.

When i perform the test i cudnt get the right wawe form. Al together was strange.

When i looked it up, i noticed that under the screw (rotor) there are two broken plates. I gues this is one side of capacitor witch broke and fell of when i tuch them.

today i got mail from person in your company witch ask me if i need variable capacitors. So i am happy as shit. juhuhuhuhu.

I can post mail of this personif somebody needs spera parts in the future.

thank you wery mutch.

Re: adjustable capacitor C5 and C8 replacment

Posted: Sat Apr 21, 2018 4:28 pm
by jaxllax
hello friends, I have a doubt with the cover condenser c3, is it obsolete. or it can be cause of calibration problems, in no manual side mention c3, and neither does it include material list, probe delete c8 change c7 by 100 pf, nothing seems to solve problem of calibrated amplitude to 1V. Set SW2 & SW3 to
0.1V and X5 respectively
  PCB version H

Re: adjustable capacitor C5 and C8 replacment

Posted: Fri Jun 07, 2019 4:16 pm
by jaxllax
en mi caso pude solucionar el problema reemplazando los condensadores C5- C8, por algún motivo estaban defectuosos , en aliexpres pude encontrar reemplazos, cuando reemplace trabajo la compensación y pude obtener una onda cuadrada