View Single Post
  #3   Report Post  
Posted to sci.electronics.repair
[email protected] etpm@whidbey.com is offline
external usenet poster
 
Posts: 2,163
Default How Do I Make a PCB Shock Resistant?

On Wed, 17 Jun 2015 05:37:33 -0700 (PDT), Matthew Connor
wrote:

Good morning, all. I'm brand new to hands-on electronic repair so please pardon any silly questions.

I recently acquired a Geiger counter manufactured in 1962 and I am rebuilding it. The PCB is 4" x 4" and 0.062" thick. The part of the chassis to which it mounts has four steel legs that protrude 1.45" perpendicular to the plane of the chassis. The four corners of the PCB screw onto these steel legs.

I would like to know some options for making the PCB more shock resistant should the unit ever get dropped. Is there any such thing as, say, shock-resistant washers that could go over the four screws and sit between the PCB and the steel legs to which it's mounted? Or is there a better way?

Any suggestions geared towards a newbie would be greatly appreciated. Thanks, all!

Kindly,

Matthew Connor

If the PCB was free from damage caused by shock when you got it then I
would suggest that it was probably built robuslty enough already
considering that it has survived for 53 years. Certainly if you are
exposed to radiation strong enough to cause you to drop the thing you
won't be living long enough to care if it broke when dropped. What
radiation source are you going to use to test it? Many if not most
smoke detectors have a little Americium that irradiates the air in a
little chamber. Removing the cover allows this radiation to, well,
radiate into the local environment and is a pretty good source to see
if your counter works at all. Another common source for radiation are
the 2% thoriated tungstenTIG welding electrodes. They will not make
your counter click as often as the smoke detector source though. The
mantles for Coleman type lanterns also used to have thoria in them
though I think another rare earth is now being used. Once you know
your counter is working it is fun to see what else in your environment
is more radioactive than the general background radiation. Certain
rocks may be more radioactive as well as concrete. Some green
glassware and some glazes on ceramics are radioactive.
Eric