Hi Robert, Should there be insulators under the two bias diode packs on the rear of the chassis above the driver and final transistor ? The same kind of insulators you put under the driver and final transistor. I am working on one, and it did not have any. thanks, kevin rea lancaster, calif.
The bias diodes need to absorb heat from the final/driver in order to compensate the bias voltage for the final/driver. Insulators for the bias diodes? No. Some heat transfer compound is needed to help them do their designed job - yes.
HaHaa! lol. Someone finally noticed! Funny story next...I had my magnifier headset on when I made that video and couldn't actually see the meter hardly at all - due to the magnification. I noticed that the mA were far too high after I took off the headset and posted the video. I readjusted it down to 35mA. Glad someone actually paid attention and said something
You are welcome mate.😉👍 Nice Video btw. I adjust Bias between 40 and 50ma for the 2166 and 50-60mA for the final 1969 or 2312. A slightly higher bias is not critical and gives sometimes better linearity. 73s Ralf
Hi Robert,
Should there be insulators under the two bias diode packs on the rear of the chassis above the driver and final transistor ?
The same kind of insulators you put under the driver and final transistor.
I am working on one, and it did not have any.
thanks,
kevin rea
lancaster, calif.
The bias diodes need to absorb heat from the final/driver in order to compensate the bias voltage for the final/driver. Insulators for the bias diodes? No. Some heat transfer compound is needed to help them do their designed job - yes.
thank you very much Robert.
When you switch to adjust the bias on the final do you switch to the other test point ?
Yes.
Your meter shows 352, 8mA. Way too much. Should be 35 - 50mA. 73s
HaHaa! lol. Someone finally noticed!
Funny story next...I had my magnifier headset on when I made that video and couldn't actually see the meter hardly at all - due to the magnification. I noticed that the mA were far too high after I took off the headset and posted the video. I readjusted it down to 35mA. Glad someone actually paid attention and said something
You are welcome mate.😉👍
Nice Video btw. I adjust Bias between 40 and 50ma for the 2166 and 50-60mA for the final 1969 or 2312. A slightly higher bias is not critical and gives sometimes better linearity.
73s Ralf