EMRFD Message Archive 52

Message Date From Subject
52 2006-08-02 07:23:27 Stan 1N400x diodes used as PIN diodes - a question
I have seen the power diodes 1N4005 used as a PIN diode for rx/tx
switch, not sure how well they worked. I was told that all 1N400x
series were not internal the same basic design. (?)

Since this is not a data sheet application for the diode, I wonder if
anyone on the list has experience using the 1N4004 or 1N4007 in a PIN

Thanks, Stan
53 2006-08-02 08:36:24 Michael Harnage Re: 1N400x diodes used as PIN diodes - a question
The 1n4007 will work better. Google "1n4007 pin diode"
for a bunch of info.

73 de w1mt

54 2006-08-02 08:53:37 AJ4AY Re: 1N400x diodes used as PIN diodes - a question



The Elecraft K2 uses 1N4007’s for TR switching on the RF board.


Go to the Elecraft site.  Select Manuals and Downloads.  Select the K2 Appendix B (schematics and block diagram).


Mobile , AL

55 2006-08-02 11:39:43 Stan Re: 1N400x diodes used as PIN diodes - a question
Thanks fellows. The suggestion to google "1n4007 pin diode" was a
good one. A lot of interesting comments. I think I will be safe
and only use the 1n4007.

Now to build me up a couple of T/R switches.

59 2006-08-02 12:09:28 Wes Hayward Re: 1N400x diodes used as PIN diodes - a question
Hi Stan, et al,

I've had a lot of experience with the use of rectifier diodes in PIN
RF switch applications. Section 6.8 is all the result of
measurements. Also, take a look at the 1995 QEX article that is
item #35 on the list of CD articles. That scheme worked well at
powers well beyond the 100 watt level. The diodes were larger than
the 1N4007. But as reported there, the 1N4007 worked well at 100

The guys at Elecraft have done some good work with their system.
The circuit that develops the high voltage needed to back bias the
diodes when "off" is well worth lifting. (I assume Wayne won't be
upset with this suggestion. After all....)

The 1N4007 is a high voltage part while the 1N4001 is only a 50 volt
part. The scheme that produces high breakdown is the same one that
yields long carrier lifetime, which is needed for low IMD. Hence,
the '4007 is going to probably be the preferred switch. I have not
done IMD measurements on the 4001, but IIP3