Hey, station managers! We want to talk. Give us a shout here to talk about how The Public Radio could fit into your next fund drive!
It's radio monogamy.
Our interaction with FM radio today is simple - we just turn on and off the power. We rarely change stations, and *never* use those seek and scan buttons.
We've gotten rid of all the parts of FM that are now obsolete, leaving only what matters. The Public Radio has all you need - just an antenna and a volume knob.
How it works
Let's get one thing clear: The Public Radio only tunes to one station - your favorite one. When the campaign ends, we'll ask for your station's frequency & call letters, and will tune your Public Radio to that station before it ships.
The Public Radio is secured in place with the Mason jar's screw-on ring. The telescoping antenna screws through the lid, and batteries are accessed by removing the radio and installing them inside.
At the heart of The Public Radio is a Silicon Labs Si4831 FM IC. Its output is passed through a Texas Instruments TPA2005D1 class D amplifier which drives a 4 ohm 1.25” speaker by Dayton Audio. The Public Radio is built on sturdy FR-4 printed circuit board, and houses a couple custom components, including a switched audio taper potentiometer and a seven segment telescoping antenna. The entire assembly is sandwiched together with our stamped stainless steel lid.
We spent a lot of time trying different assembly configurations and hardware specs. If you've got a hankering for details, shoot us a note - we're happy to geek out about it :) You're also welcome to check out our GitHub page, which has open-source versions of our EagleCAD files.
So... Why a Mason jar?
Honestly? It was an accident. At first, we imagined an enclosure with a more contemporary aesthetic. But we needed to evaluate speakers in the meantime, and used a jar and a piece of cardboard as a stand-in. After trying it for an afternoon, we realized that it was just more fun to use something that was *literally* on our shelves.
The standard version of The Public Radio comes with its own 250mL square (ish) Ball jar, but you can swap the hardware out into any wide-mouth jar that you like.
We've been working hard on the Public Radio for the past eighteen months, iterating our designs and building on feedback we received from our beta launch on Grand St. We've gone through seven PCB revisions to date, and have learned a *ton* about FM reception and circuit design in the process.
For the last three months we have researched, designed and ordered a handful of the custom parts necessary to make a small production run of The Public Radio. This includes the radio's custom potentiometer and antenna, both of which we received this June. We've also spent countless hours poring over our bill of materials, searching for ways to drop costs - and have researched & vetted our supply chain along the way.
Some of the radio's hardware components (such as the custom lid) require big setup fees, and we need your help to cover them. Support the project by pre-ordering your own Public Radio and help make this a reality!
Who we are
We're Zach Dunham and Spencer Wright, two childhood friends now living in Brooklyn. We ran around together as kids, and then went on to be hardware design, project management, and audio aficionados. After taking MIT's circuits & electronics class, we started hacking together on weekends, and eventually came up with a fun, compelling idea - that we finally had the skills to complete.
We had *tons* of engineering help from Todd Bailey and Andy Warner. Special thanks to Alexis Arkus-Duntov, Jonathan Bobrow, and Daniel Fishkin for their concepting help, and to Colin Reilly for cinematography.
We also couldn't have gotten this far without the help of our beta testers - thanks to Robert K, Ross W, Kristen S, Elana O, Harry J, Shawn F, Tracy L, Greg A, Ada P, Jacob C, Robert C, Paula P, Janna L, Cheryl R, Linnea J, Saralyn C, Robert L, and Henry L!
Risks and challenges
We're confident with our mechanical and electrical design, but some logistical questions remain. Foremost in our minds is building a system that allows us to tune and then track unique radios to each of our backers as they come off of the production line. It'll be a bit tricky, but our fabrication partners are aware of the issue and have a preliminary plan to deal with it.
We're also anticipating some work in the management of vendors and manufacturers of our custom parts. We have parts coming from about a half dozen suppliers, and tracking their progress and dependencies will be a full-time job. But we've managed jobs of greater complexity before, and ultimately this will not be an impossible task.
Another expense (and logistical hurdle) will be the FCC tests that we're subject to. These will cost a few thousand dollars and will inevitably require a bit of effort and management. But ultimately, our production and testing partners are well-versed in this territory (and the specifications we need to pass are relatively easy), so we feel confident that it won't be a major issue.
We also need to find a clever use for all of the standard Mason jar lids that will come with the Public Radio's jars. We'll probably end up using them to make pickles, and there's always the chance that we ship out jars of those instead of the radios... but we're pretty sure we can keep them straight ;)Learn about accountability on Kickstarter
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