**this instructable will walk you through the process of turning a portable antique radio into a cool looking Hi-Fi bluetooth speaker. it takes into account that you have experience in soldering, working with basic electronics, and enough mechanical dexterity to be able to take things apart and put them back together successfully.**
i realize not every builder is tech savvy so here's a quickie on bluetooth. bluetooth is a wireless data transfer protocol that uses the same radio frequencies used by 2.4ghz wireless internet (wi-fi) connections. it doesn't work on a network, it connects devices directly to each other and is short range only. 10 feet is about average coverage for bluetooth devices. a bluetooth speaker must be "paired" to a device in order to work. it can be a bluetooth capable cellphone, ipod, computer, or other music playing device. for pairing instructions see the manual to your device.
while normally i prefer to restore most antique radios that come my way, there's a significant under-appreciation for antique tube portables. with few exceptions, most don't bring much in the collector market and their isnt much love for them. i think they look quite cool. some, like the Delco model i used, are wrapped in tweed. what jazz lover doesn't dig tweed?!?!?
my goal was to take this cool tweed covered AM radio, and re-purpose it into something that would look right amongst my other vintage gear yet serve a modern day purpose. i had been wanting a portable bluetooth sound box of some sort for a while and those panzy little extendo speakers didn't suit my taste. i wanted something a bit cooler looking. that's what led to this project!
so, onto the build out!
Step 1: what you'll need for the build
at minimum, you'll need a working bluetooth speaker with good battery life and a suitable portable radio. this would be bare minimum though and i recommend a few more items.
for my build out i decided i wanted long battery life and improved audio. for the battery i used a 3.7v lithium extended capacity phone battery. this battery spec'd out at 3500mAh versus the 500mAh battery that was part of my donor bluetooth speaker. this should give me about 10hrs playtime between charges at reasonable volume. the stock bluetooth speaker battery was good for maybe 2hrs or so.
for the speaker, i used a driver yanked from an old surround system. this speaker had a high compliance cloth roll surround. this will give me more low end and fuller sound. foam surround speakers are much more common but all eventually fail due to foam rot. i'm not a fan of foam surround speakers for this reason. i recommend going with anything other than a foam surround driver.
why not re-use the original radio speaker?
you can, but chances are it wont last very long and it will sound squawky. it was designed for half a watt or less of audio and not really meant for full range music. save yourself twice the work and just get a replacement speaker. even the cheapest bluetooth speaker amps easily put out more power than the old radio speaker can handle.
in pic 2 you see some of the items i laid out for this project. i ended up not using the stand alone charger but all the other stuff got used in this project.
a word about donor radios..
while most portable tube radios don't get much love in the collector world, early transistor portables do. there were some lunchbox sized early transistor portables that at first glance may look like an old tube radio. these are obscure and hard to come by as they were really expensive in their day. if you do find one, don't hack it. sell it off on ebay and you should have enough cash to buy two or three tube portables.
if you find a zenith transoceanic tube portable, those are valuable as well. the very early ones from before WW2 can bring hundreds of dollars on ebay. don't hack a zenith transoceanic!