Hi,

I need a clarification on how to identify a Germanium Diodes spec which doesn't have any markings on that except a green band.
It is in RF tuning assembly's signal reception device.
Seems to a rectifier for RF signal.
Its a clear glass type material made with orange colour at both side lead insertion and a green colour band at on end.

Thanks.

 

At a guess, it will look a lot like a 1N34.

 

Could also be a voltage-variable capacitor diode use to tune the LC network. How do you know it is Germanium? Did you forward bias it and measure the forward drop? Look at your circuit again. If the diode is reversed biased there then it is almost certainly a VVC.

 

It's been labelled as CR1, Ge on the PCB, that's why i guess its a Germanium.It's been connected in series with a ceramic capacitor C1 at anode and inductor L1 at cathode. RF been fed to the circuit in series through C1. Signal leads through L1, in series to circuit.Any suggestion?

 

Can you attach the circuit or that part of it?
IOW, show us the schematic.

 

here's the schematic

 

The best way I know to test them is out of circuit, using a DMM in the diode mode. A germaninum diode will have about .25 volts forward drop as opposed to a silicon with .6.

The schematic certainly looks like an R.F. detector. Germanium diodes are preferred in this application specifially BECAUSE of their lower forward drop.

eric

 

ok, thanks so far.but once I found out its a Ge diode, then how bout the specs? like Vmax and aplications.. etc.

 

See post #2.

 

I wonder if it could be a 1N35 (orange green=35). Sort of a long shot,

 

Hi beenther,Thanks.Is it a point contact diode, or similar? Hi Ron H ,1N35 is similar to 1N34 but 22.5mA rate, where the latter is 50mA rate. Correct me if I'm wrong. If that's the case, can use either depends on the application needs?

 

Hi beenther,Thanks.Is it a point contact diode, or similar? Hi Ron H ,1N35 is similar to 1N34 but 22.5mA rate, where the latter is 50mA rate. Correct me if I'm wrong. If that's the case, can use either depends on the application needs?

"Rate" is not a property of diodes.
I looked at the American Microsemi specs for 1N34 and 1N35, and they don't make a lot of sense.
What is "output current"?
Why does V(FM) Max = 1V at a few milliamps?
These are rhetorical questions, at least for you, so don't try to answer them.
I don't know the answer to your questions, but it wouldn't hurt to try 1N34, which should be readily available.

 

"Rate" is not a property of diodes.
I looked at the American Microsemi specs for 1N34 and 1N35, and they don't make a lot of sense.
What is "output current"?
Why does V(FM) Max = 1V at a few milliamps?
These are rhetorical questions, at least for you, so don't try to answer them.
I don't know the answer to your questions, but it wouldn't hurt to try 1N34, which should be readily available.

Hi, I don't really get wat u mean, may be I'm wrong with my question.Anyway, i measure the forward drop V, 3.6mV on my DMM.I've attached the image of it.Thanks

 

At what current did you measure the 3.6mV drop?

And is that 3.6mV just one way? (meaning, is the diode not shorted?)

 

I measure as suggested in previous post, taken out diode form circuit, using diode continuity test mode in DMM.
and apologize for the error. It's not 3.6mV but 0.36V.