On Thu, 07 May 2015 07:53:07 +0100, Jim GM4DHJ ... wrote:

"Brian-Gaff" wrote in message
...
Well says it all. I have a little door phone and after about 6 months
trying to keep the call/bell button has been abandoned in favour of an
old bell push I found in a drawer with a Woolworths price tag on it.
This is wired so it shorts the intercom cable as the original failed
one which consisted of some tacky little push switch on a pcb glued in
with heat glue. the Woolies on is your basic two brass bits sprung
apart and a plastic button to short them together.
Tis worked fine till one of two things happened. Firstly, its not
waterproof and when its really wet, it shorts enough to make the bell
sound or make silly whining noises leaving the amp running with clicks
and groans. Or, the local cold caller or whoever who seems to have
been studying finger karate, squishes it so much the prongs stay
shorted out when the finger is removed.
Most bell pushes seem to still be of this type. I had no idea of the
stringent needs of a bell push in this environment before, so wondered
if anyone else had any bright ideas?
Brian

I gave up replacing my bell push a decade ago because of that
problem....if anybody knows a reliable type though .....

Some DIY with a magnet and a reed switch...I know there may be a current
problem, but that's just another DIY solution. My bell push only has to
take a fraction of an amp...