[Hallicrafters] Piesoelectric effect case in point.

[Peter Bertini]

Hello to the group...

I have been very careful in stating that the Piezo effect probably would
cause any noticable problems in boatanchor gear. But, even the manufacturers
acknowledge that it exists, and the reasons:

http://my.execpc.com/~endlr/ceramic.html

Unfortunately this thread has taken so many turns and branches that it is
impossible to follow and know exactly what is being replied to at this
stage; thus I am begging out of further discussions. My only point was that
capacitors have specific electrical traits and one size doesn't fit all.

73 to all, and a Good New Years to everyone.

Pete

On Sun, Jan 2, 2011 at 4:31 PM, Glen Zook <gzook at yahoo.com> wrote:

> There may not be any way that a ceramic disc capacitor can become a
> transducer, but I have, on very rare occasions, heard audio coming from a
> disc ceramic capacitor that has been used for coupling in an audio circuit.
>  Replacing the capacitor, usually with a "poly" type, has cured this
> "problem".
>
> I have also run into an occasional problem where, when "tapped", a disc
> ceramic capacitor did act microphonic and introduced the "sound" into the
> audio chain.  Have run into this on both transmitters and receivers.
>
> Probably, replacing with another ceramic disc might have solved the
> problem.  One that did not have whatever "defect" which caused it to act
> like a speaker.  However, when I do experience this I just replace the disc
> ceramic capacitor with a different type and go on to the next problem.
>
> Glen, K9STH
>
> Website:  http://k9sth.com
>
>
> --- On Sun, 1/2/11, rbethman <rbethman at comcast.net> wrote:
>
> Having just researched ceramic capacitor construction, I don't see ANY way
> that these would have the ability to become a piezo transducer, OR having
> anything to do with these old boatanchors.
>
> You "may" want to do a bit of research also.  They also manufacture "dipped
> ceramic" capacitors.
>
>
>
>