[TenTec] Low Pass Filter

[Dr. Gerald N. Johnson]

On Tue, 2008-05-20 at 13:29 -0400, ron wrote:
> Rick Denney wrote:
> > As a tuba player, I'm intimately familiar with harmonic resonance (I
> > didn't say "musical", heh). Normal play of a brass instrument requires
> > exciting resonance at some multiple of the fundamental resonant
> > frequency of the bugle.

And the french horn is the most treacherous with common valving for
adjacent notes throughout much of its register. Like the top octave of
the tuba.
> >
> > Sorry for the tangent, but the conceptual parallels between brass
> > instrument acoustics and electromagnetic fields are remarkable, and
> > Dr. Jerry opened the door. The frequency domain, once entered, reveals
> > surprisingly similar scenery.

The parallels between radio and acoustics are far closer than most would
think. Sound propagation down a pipe or in a room is solved by the same
exact differential equations as RF propagating in the same shapes. Sure
the meanings of particle velocity and pressure are replaced by voltage
and current but for the same boundary conditions, the solutions are
exactly the same.
> >
> >   
>  
> Nicely in perspective, Rick.
> any comments from Trombone players??

I've played trombone in public, but I preferred  Bb tuba in those days.
The tuba in my attic is an Eb. I've played trumpet in public, but
probably shouldn't have. I've played french horn in private along with
baritone sax. I've played a few notes on my antique clarinets. I've
played bass drum, snare drum, tympani, triangle, tubular chimes, tam
tam, and bells in public, but for some of those the group performances
would have been improved had I stuck to double bass which is my best
instrument these days. I didn't respond to this thread about filters
last night because I spent the whole evening in rehearsal for a Story
City, Iowa community theater production of Beauty and the Beast which
opens June 4. It was the first time the orchestra and cast worked
together on this production. I think its my 61st musical.

73, Jerry, K0CQ
> 
> (smile)
> 
> Ron
> "the 516 is a keeper"