On Wed, 14 May 2008 12:03:57 -0700, Jitt wrote:


The page is scanned from the 1964 Radio Amateurs handbook,
and contains data for several old transistors besides CK722.
If it is of interest, I'll post a cut section containing the
line of interest.

snip

First the line...

Both came through ok on this server. Thanks for the help.

The 180mW dissipation is the 25degC ambient extrapolation using the
4mW derating to zero power at 70degC ambient from the 1955 tentative
data. I don't believe that later figures were actually published, as
point contact devices were quickly superceded in industry.
Manufacturers didn't use ambient deratings for long - shifting to case
temperatures PDQ.

At 50deg ambient, that becomes the 80mW rating given on the 1955
tentative data sheet.

RL