[Hallicrafters] The Law of Smoke

[Jim Tripp]

After reading Rich's "observations" (below), I have spent much time
dwelling on the behavior of smoke. As a result of this I have
postulated a formula governing "The Law of Smoke" and I think it
should be taught right along with Ohms Law, Kirkoff's Laws, etc.  I am
amazed it has been neglected this long.  Hopefully this formula will
allow us to study this phenomena in much greater detail in the future.

I suggest the following formula:

The Law of Smoke:  S = kP x T

Where:
S = smoke expressed in cubic feet per minute P = power dissipated in
watts T = time since the component was installed, in seconds.
k = the coefficient of the medium involved in cfm/watt-seconds

We can see from this formula that the longer a component has been
installed the more likely it is to expel smoke. Equivalently, the more
power the unit dissipates then its greater propensity to expel smoke.

Our only saving grace is the factor "k". We are obligated to select
components with the smallest k-factor possible.  For example, glass
has a very small k-factor and is highly unlikely to emit smoke.
However, paper has a very high k-factor and is almost sure to emit
smoke given an adequate amount of power and time.

Now that we have this formula, it is our obligation to determine if
"S" is greater in a Hallicrafters then it is in a Collins. 

I think it has empirically been proven that radios with a large number
of paper capacitors emit smoke more frequently then those that have
had their paper caps replaced with Mylar capacitors.

I would like to express my sincere thanks to my colleague, Rich
Oliver, for his invaluable research in this area.

QED

Jim/wa6dij, Professor at Large, Department of Science Nonsense.


-----Original Message-----
From: Rich Oliver [mailto:Rich.Oliver at lowell.edu]
Sent: Thursday, September 15, 2005 12:39 PM
To: Jim Tripp
Cc: hallicrafters at mailman.qth.net
Subject: Re: [Hallicrafters] daffynitions

Jim,

One fact that is often overlooked is that all electronic devices run
on smoke.  When you let the smoke out they stop working.  Reloading
smoke into dead devices is generally beyond our capabilities (except
Gary Brown?) so we usually settle for replacement parts with a full
charge of smoke.  "Black Beauties", carbon comp resistors and such are
slightly porous so the smoke leaks out slowly over time, then the last
bit of smoke comes out all at once.  Tubes are trickier because the
smoke stays inside the glass envelope and you have to open the
envelope to check for smoke.  I have checked all my tubes and I'm
happy to report that no smoke leaked out of any of them - now I just
need stuff the vacuum back in and put them back together.  Gary - need
some help here!

Most electronics text books just gloss over the critical role of smoke
if they mention it at all.  It is also generally ignored in school
courses even though the astute student will nearly always encounter it
in electronics labs.  For some reason the instructors just sit back
and allow the student to make the connection by himself.

*COUGH*

Cheers, Rich