Re-Radio: July 2016

I've been refurbishing old radios for a while, turning them into Bluetooth speakers. I buy non-working radios and old radio cases, take the insides out, and refit them with a Bluetooth receiver and amplifier and new speakers.

I gave my daughter one, my wife one (the I helped my son make), a friend of my daughter's one, and I use one in my garage to listen to when my son and I work out. There's another in our bedroom and two more completed but not currently being used sitting in the living room on a table. Gifts maybe? Dunno. I haven't quite decided what I want to do with them.

Both my daughter and her friend kept telling me I should make a blog about it and how cool all their friends think their "radios"are.

So....

One of my recent acquisitions is this Admiral Model YG743. I got it off eBay for around $25 including shipping. I set that as my limit when I do my searches.

It's in pretty good shape, but it does have a chip out of the plastic edge on the left side which I failed to notice when I ordered it. I need to look closer at the photos.

Front and front top down views:

Here's a rear and rear top-down views:

It's pretty dirty, so the first step is to take it apart and clean it. Here it is with the back off. You can see the wire attached to the antenna. Lots of dirt/dust!

I snip the antenna wire so I can take the back completely off. I need to pull off the two knobs on the front so I can remove the circuit board. There's a screw holding the circuit board on behind one of the knobs!

Once the screw is removed, I snip the speaker wires and remove the circuit board.

I don't need the speakers - they are old, poor quality, and not able to handle the 25 watts per channel amplifier I'm going to use. They would sound awful.

Here's the radio with all the insides removed. You can see how dirty everything is.

Next step is getting it all cleaned up. Just a simple case of spraying it with a hose and wiping it out. I spray the circuit board too: the radio doesn't work so I don't care about getting the circuits and components wet. DO NOT get the compressed fiber board back wet, as it will swell; just wipe it down with a damp rag.

Water and a toothbrush, all you need.

All cleaned up and drying in the sun.

I don't need the electrical cord, so I snip it off. I might need the radio-side plug though; it plugs into the circuit board and helps hold the back on. I won't know for sure until I start putting the new speakers and amp in and see how everything fits, so for now I leave it.

I don't need the antenna though, so I take that off. You can see the back side of the plug there that I'm talking about.

No more antenna!

The new speakers go in next. These are 4-inch speaker I picked up either at the local flea market or Goodwill for around $3 - $5 for the set. Every few weekends, I hit up the local flea market and Goodwill for their speaker offerings. I buy old speakers, take them apart and remove the actual speakers from the enclosure. Four-inch speakers are pretty easy to find, although I have had to order them off Amazon in the past.

With this particular pair, I have no idea what the ohms and max wattage is. Just have to see how it sounds once I get them hooked up.

Speakers in! I had to use washers on the top edge to hold them.

Adding the wires to the speakers. I stripped the ends and attached them to the speaker posts. I have a bunch of speaker wires with post attachments.

Handy-dandy wire strippers.

Wires attached.

With the speakers in, it's time to put the circuit board back. The knobs on the front need the circuit board to stay on; it's either that or use some rubber o-rings to hold the knobs in place. When possible, I use the old board, as the knobs are sturdier when attached to the original equipment.

I pulled out the tubes to make more room. Board back in.

I was lucky that it just fit. You can see below that if the speaker stuck up any more, I'd have had to do some tinkering. I would have had to loosen the bottom of the speaker and slide the corner under. Pretty minor compared to some of the things I've had to do to get everything to fit.

Here's the power supply. It puts out 12 volts at 3 amps, that means it will put out a max of 36 watts (volts x amps = watts). I cut off the plug to attach it to the Bluetooth receiver/amp and feed the wire through a hole in the back board. I tied a knot so it wouldn't pull against the connections.

The Bluetooth receiver is integrated with an amplifier that puts out a max of 50 watts (25 x 2). The power supply above is the most powerful I've found that is still a "wall wart". To get anything more powerful than 3 amps, it's ends up being like a laptop computer power supply with a separate converter box. I prefer the "wall wart" as it is more compact.

Here's the Bluetooth receiver and amp.