Cant set dc balance on gwh-109

Removed emitter from Q1 measured 40kohms , replaced VR1 same number pot , measured 0.600mv at lowest setting and measures 158k ohms from emitter of Q1 to VR1

Well, you can pull q1 completely out and see what the output DC offset goes to without it's influence.

I still cannot decipher from your posts whether more or less resistance is needed to get q1 into the proper operating range.

Then the post of "0.600mv" leaves plenty of questions - like 0.6 VOLT or 600 millivolts or less than one millivolt.

I am going to try one more (last?) time to get the data I need.

first, completely disconnect Q1 and measure the DC offset voltage at the output. xx.xxx Volts

with Q1 in circuit, jumper B open and VR1 at one end of it's rotation, what is the measured DC offset voltage at the output? xx.xxx Volts

with Q1 in circuit, jumper B open and VR1 at THE OTHER end of it's rotation, what is the measured DC offset voltage at the output? xx.xxx Volts


with Q1 in circuit, jumper B CLOSED and KEEPING VR1 at THE OTHER end of it's rotation, what is the measured DC offset voltage at the output? xx.xxx Volts

with Q1 in circuit, jumper B CLOSED and turning VR1 BACK to the original end of it's rotation, what is the measured DC offset voltage at the output? xx.xxx Volts

These five voltage readings give me a fighting chance at figuring things out.

The next step would be POSTING PICTURES where I can POINT at the measurement points for taking power off resistance readings.

Just to reiterate - any resistance - also called ohms - readings MUST be done with the power off and power supply voltages decayed (by time) to sub 1 volt levels.
 
Ok markthefixer i am very sorry i appoligize , been dealing with a death in the family.Lot going on and close to loosing my mind last friday i finally got a minute and retested all resistors and trans on gwh-109 ,moved on to caps and found c1 completly open and c3 half of what it should be .Now these were brand new from mouser,replaced both caps c1 c3 reconnected cut jumper wire and bingo everything is normal ,im sorry i have not checked on thread so i didnt see your reply ,
 
Back
Top Bottom