[Elecraft] Sorta OT - assistive technology assistance

[Ken Winterling]

JR,

Another approach to help your friend is to buy and install an inexpensive,
simple mixer as he can clearly make use of it now.  You can still build a
mixer for the experience.  After taking whatever time is necessary for
designing, building, and debugging in your shop you can try it out at your
friend’s location for a “real world” evaluation by a real “end user”.  His
feedback may give you an opportunity to provide improvements to your design
or tailor it to his specific needs/desires.

Ken
WA2LBI



On Fri, Jan 11, 2019 at 10:57 Walter Underwood <wunder at wunderwood.org>
wrote:

> Since you are dead set on building one from scratch, start here.
>
> https://www.google.com/search?q=audio+mixer+circuit
>
> You'll see a lot of four-channel mixers because quad op-amps are cheap,
> under $1.
>
> This one has the pots before the op amps.
>
> https://www.allaboutcircuits.com/projects/build-an-audio-mixer/
>
> This one has the pots after the op amps.
>
> http://www.theorycircuit.com/audio-mixer-circuit/
>
> I’d be interested in the parts cost after you have chosen a design.
>
> wunder
> K6WRU
> Walter Underwood
> CM87wj
> http://observer.wunderwood.org/ (my blog)
>
> > On Jan 10, 2019, at 11:36 PM, Richards <jrichards at k8jhr.com> wrote:
> >
> > THANK YOU for the several replies to my mixer circuit question - both on
> and off the list.  Unfortunately, few actually answered the original
> question,  most often advising me to abandon the project or mix on a
> computer sound card.
> >
> > First - Thanks, Steve, for your input based on personal experience.
>  While I am familiar with your mixer, Tom prefers a device with stereo
> channels and outputs for both headphones and powered speakers. The model
> under consideration has only two control pots, making it easier to manage.
>  Tom truly appreciates your personal input and direct correspondence off
> list.   He puts a lot of stock in your take.
> >
> > Second - Tom prefers a simple hardware solution.   Locating a manual
> control next to the rig is much easier (for him) to manage, than mixing
> with a computer sound card.   Navigating multiple operating system windows
> is a serious challenge because he cannot see the monitor or use a mouse.
> This is not the preferred method for a contest or snagging rare DX before a
> pileup ensues.  Mixing on a computer would be very inconvenient;  close
> your eyes and try it some day!   It's easy for you to say ... but, not so
> easy for my friend to do.
> >
> > Third -  We can simply purchase a commercial product  (I recommend the
> Rolls MINImix MS22s stereo mixer, with just two pots, and outputs for both
> headphones and speakers)
> >
> > UNFORTUNATELY, THAT DEFEATS THE WHOLE POINT BEHIND MY QUESTION.
> >
> > While I do NOT wish to look a gift horse in the chops, or appear
> ungrateful for the advice received so far;  money is not the object as I
> want to LEARN how this type of circuit works, and do a favor for a friend,
> in one stroke. Advising me to save money and just buy a turn-key,
> off-the-shelf solution hardly fits the HAM RADIO TRADITION of
> experimentation and self-determination,  and teaches me nothing about
> circuit design.   I was hoping to build something MYSELF- earning that
> heady sense of self-satisfaction that accompanies the completion of a
> successful home brew project.  Considering all the experts on this list,
> including world class board certified AES audio man Jim Brown, I figured a
> simple summing circuit would be a snap.
> >
> > I close this thread with a big THANK YOU on behalf of my  ... um ...
> "client,"  whilst I repair to the proverbial drawing board to renew my
> search for a simple summing circuit.
> >
> > Happy trails to all.       JR
> >
> > (We return you to your regular daily programming content)     ;-)
> >
> > -----------------------------------------------------
> >
>
> --

Ken
WA2LBI

Sent from one of my mobile devices