ua79

[desperadogear]

what is the expansion of OA in OA79 diode? AM detector diode.. and can we use an ordinary diode in its place for AM detection ? if not why?

 

[Russlk]

What are you talking about? What is a UA79 diode? I never heard of it.

 

[akg]

do u actualy mean OA79 (Ge AM detector diode).?

 

[desperadogear]

i am extremely sorry it is the AM detector diode. It should be OA79.. i was asked this question when i attended an interview for a job. i dint hear properly. pls tell me whats its expansion

 

[Russlk]

The OA79 is a germanium diode, the forward drop is about 0.35 volts. If you mean silicon diode as "ordinary diode", the forward drop of silicon is 0.5 volts, so it will not work as well as a detector.

 

[desperadogear]

thanks russlk

i got the reason why ordinary diode cant be used ... is there any expansion for notation OA??

 

[Nigel Goodwin]

i got the reason why ordinary diode cant be used ... is there any expansion for notation OA??

It's from a VERY, VERY old coding system, that was later replaced by the 'Pre-Electron' system.

'O' means a semiconductor device.

'A' means a diode.

Another option is 'C' for a transistor.

 

[desperadogear]

thanks !!

thanks a lot. that answers my question