[Milsurplus] 1N21's and 1N23's

[WA5CAB at cs.com]

While it is true that newer diodes might be found that have electrical 
characteristics close enough to the 1N21 and 1N23 to replace them without 
significant electrical circuit changes, it should be pointed out that mechanically 
there will be a problem.  If you just go out and buy a handful of axial 
wire lead diodes, they are not going to come anywhere close to fitting the 
holder in the equipment you are trying to fix.  Can adaptors be made - yes or 
probably.  Does the average ham or non-ham collector have either the equipment 
or the ability to make the adaptor - probably not.  The "modern" diodes 
referred to look like 1/4 or 1/2 watt resistors with glass bodies.  The 1N21(*) 
and 1N23(*) look somewhat like .22 Long Rifle rounds (or maybe .25 ACP) 
with the bullet turned down to about 0.1".  The holder is not going to fit an 
axial lead diode with very small flexible leads on each end.

In a message dated 12/14/2009 11:57:50 PM Central Standard Time, 
dennis.monticelli at gmail.com writes: 
> These are point contact (i.e. early Shottkey type) diodes that were 
> graded
> for freq and noise figure.  The 1N21 was Ge and the 1N23 was Si.  Yes, 
> they
> were fragile both electrically and physically hence the lead wrapper used 
> in
> some cases.  You can probably replace them with modern glass encapsulated
> Shottkey diodes.
> 

Robert & Susan Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480