I usually like to build stuff when I can, but I have to agree with the others who suggested a commercial mixer. They are cheap and work well. I recently bought a small behringer USB mixer for under 50 bucks for a project at work. It acts as a USB sound card, so you can mix audio to or from the PC with other sources. You can adjust levels, equalization, and position (left/right) for each source. I doubt one could homebrew an equivalent unit any cheaper. Good luck with your project! I’m sure your friend will appreciate it.
On Wed, Jan 9, 2019 at 5:30 PM Don Wilhelm <donw...@embarqmail.com> wrote: > James, > > There was a homebrew headphone mixer in the ARRL Handbook sometime back > - simple, with op-amps to isolate the sources. > > However with the advent of 2 to 5 input mixers being available in the > $20 to $60 range (see Amazon), it seems foolish to consider building > your own - drilling the enclosure for the potentiometers and jacks, > building the board, mounting things, etc. will take more time and effort > than is reasonable unless you really like doing those things - and it > will likely cost more than buying one already built. > > The nice thing about a mixer is that you have control over the level of > each input as well as an overall output volume control. > > 73, > Don W3FPR > > On 1/9/2019 6:03 PM, Richards wrote: > > Good Day. > > > > Background: > > > > I am assisting a blind ham who also suffers some hearing loss. I > > suggested using headphones to attenuate ambient environmental noise as > > he operates. The rub is, he needs to hear both his receiver AND his > > computer (which provides audible feedback when logging contacts and > > performing other duties.) > > > > Question: > > > > Can anyone suggest a simple passive (or active) mixer circuit schema I > > can build for him to safely mix audio signals from his transceiver > > headphone jack with audio signals from his computer sound card headphone > > jack? > > > > Discussion: > > > > While there are multiple commercially produced simple and complex mixing > > products in the marketplace, I would prefer to build an inexpensive, > > small footprint solution we can easily incorporate in his station to > > minimize clutter and the number of cables, jacks, and controls -- he > > contends with plenty of that already. I suppose one solution might be > > a simple Y-adapter cable, but that seems too easy and I wonder whether > > we should isolate the signals and/or grounds in some way? (e.g., I do > > not wish to cause any "Pin-1" grounding issues, and etc.) > > > > Any traction? Can anyone point me to an appropriate circuit schematic > > or other resource? I don 't mind doing homework, and while I enjoy > > building stuff and I am familiar with the basic concepts involved, I > > could use a leg up on this project, especially to keep it simple and > > easy to build and implement. Please reply off list if this question is > > too far off topic, although I suspect there are many hams who might be > > interested in the result, besides similarly situated disabled operators. > > > > Thank you - James - K8JHR - > > --------------------------------------- > > > > > > > > > > ______________________________________________________________ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:Elecraft@mailman.qth.net > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > Message delivered to donw...@embarqmail.com > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to dave.w...@gmail.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
