[Elecraft] 1N4007 diode question?

Tue Apr 8 11:48:01 2003

May it not be a matter that the DESIGN of the 1N4007 relates to the application properly or best, while the actual comparative MEASUREMENTS or FAILURE RATE would be difficult to come by in a casual examination?

Or said another way, use 1N4004 if you want, but YMMV...or it may not, depending on whether you have stroked the Blarney Stone recently.

73, Guy.

> 
> From: "Ron D'Eau Claire" <[email protected]>
> Date: 2003/04/07 Mon PM 11:26:03 EDT
> To: "'Don Brown'" <[email protected]>,  <[email protected]>
> Subject: RE: [Elecraft] 1N4007 diode question?
> 
> I've used a great many silicon diodes as RF switches. That use goes way back
> before PIN diodes. All one needs is sufficient bias to keep the diode either
> conducting or not conducting, as you desire. 
> 
> Isn't the unique feature of a PIN diode its ability to act as a variable
> resistor to RF as the bias is varied, rather than rectifying he RF? That
> capability isn't used in a simple T/R switch like, say, in the KPA100. 
> 
> I just did a quick check and came up with the "CQ Antenna Roundup" book
> published in 1963 (FORTY years ago!) in which Don Stoner, W6TNS and L.A.
> Earnshaw, ZL1AAX describe the use of silicon diodes as RF switches with
> examples in a variety of applications. They were using early silicon power
> rectifiers in this application.
> 
> Ron AC7AC
> K2 # 1289
> 
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> On Behalf Of Don Brown
> 
> ...My curiosity got me to thinking so an experiment was in order. I went out
> and bread boarded a circuit. It looks like the entire family of 1n4000
> exhibit the PIN characteristics. I tried the 1n4001, 1n4002 and 1n4007 at
> different frequencies from 3 to 40 mHz at 5 volts Pk to Pk and they all work
> the same with a switching current of about 8 ma. Just for grins I tried a
> 1n4148 and it does not work at all. It rectifies the RF as you would expect.
> The 1n4007 passes the RF without distorting it at all.
> 
> There are several articles on the web that mention that the 1n4007 is the
> only one in the series that will work as a PIN diode but my tests seem to
> discount that. So will a 1n4005 diode work in place of the 1n4007 in the K2
> possibly, but I would still go back and use the proper part if possible.
> 
> Don Brown
> KD5NDB
> 
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73, Guy
K2AV