How is a OA79 diode different from the 1n4007 ones?

[abishek]

how is a OA79 diode different from the normal in4007 ones

i think the oa79's are used in detection circuits in am commn...any particular reason why??

 

[throwaway18]

diode oa79

OA79 is a germanium diode. 1n4007 is silicon.

>i think the oa79's are used in detection circuits in am ...any particular reason why??

Possibly because people keep reusing old circuits. The OA79 has been on the market for at least 45 years.

 

[Charles Bronson]

diode silicium detection am

The OA79 is a germanium based diode. This conducts in the forward biased direction at ~0.3Volts. Silicon diodes Conduct in the forward biased direction at ~0.6 or 0.7 volts. If you are wanting to detect weaker signals a germanium diode is a good choice. Nowadays we have good quality low price transistors that can amplify weak signals and the difference between the diodes is not that important in many circuits. Silicon is a very common material so is cheaper than germanium

Modern circuits = Good Pre-Amps = Less detection needed.

Older Circuits = Pre-Amps not so good = Better detection needed.