Intermittent xistors are not unusual, I have found but a nasty one to find at times. Glad you found the crook xistor. Here is a fantastic tip to measure a Zener diode: Get an old eye type capacitor tester with variable output test voltage. The old eye type ones have current limiting built in. Place your Zener across the test terminals /leads. Place your voltmeter across the diode. Watch the meter and crank up the test voltage knob. When you see no more change in voltage across the Zener, that is it's regulating voltage. Raising the voltage will make no difference. I have, in my experience, fount this test 99.9% reliable and accurate. If you suspect the diode is intermittent you just monitor it and can either heat or cool it. This test saved me massive time & irritation in troubleshooting. Hope it can help you & your subscribers. It is also a great test for that pile of unknown Zeners you got in a grab bag.
Hi Andy, I’m glad to see you have “finally” got there with the BGA! Thanks for sticking at it and highlighting the issues amp building entails. Looking forward to the sound tests. Those 5881’s were very reasonable, can’t remember how much exactly. : )
I suspect there may be a few more twists & turns. TBH most valve amps aren't as complicated as the BGA, but hope I show how to de-bug. I'll fettle the bugger yet.
Intermittent xistors are not unusual, I have found but a nasty one to find at times. Glad you found the crook xistor.
Here is a fantastic tip to measure a Zener diode: Get an old eye type capacitor tester with variable output test voltage. The old eye type ones have current limiting built in. Place your Zener across the test terminals /leads. Place your voltmeter across the diode. Watch the meter and crank up the test voltage knob. When you see no more change in voltage across the Zener, that is it's regulating voltage. Raising the voltage will make no difference. I have, in my experience, fount this test 99.9% reliable and accurate. If you suspect the diode is intermittent you just monitor it and can either heat or cool it. This test saved me massive time & irritation in troubleshooting. Hope it can help you & your subscribers. It is also a great test for that pile of unknown Zeners you got in a grab bag.
Good tips there. I have a little zener checker which uses the same principle you outline. TFW.
Love the big green amp - seeing it provides a learning opportunity for you and us! Looking forward to hearing it sing for us!
Лампа 6Р4П вместо 6П14П th-cam.com/video/wZ4m76vyKJY/w-d-xo.htmlsi=S21cZ6aM5nj_P455
Me too, hope you picked up a few tips & wotnot, TFW.
Hi Andy, I’m glad to see you have “finally” got there with the BGA! Thanks for sticking at it and highlighting the issues amp building entails. Looking forward to the sound tests.
Those 5881’s were very reasonable, can’t remember how much exactly. : )
I suspect there may be a few more twists & turns. TBH most valve amps aren't as complicated as the BGA, but hope I show how to de-bug. I'll fettle the bugger yet.
Лампа 6Р4П вместо 6П14П th-cam.com/video/wZ4m76vyKJY/w-d-xo.htmlsi=S21cZ6aM5nj_P455
Привет, 6N14N is equivalent to EL84, what is the point please? TFW.