The obvious solution was to build a small AM transmitter and modulate the signal with the audio output from my computer. I built a very simple, low-cost, low-power AM transmitter:

Simple AM transmitter schematic

However, I had some self-imposed restrictions to overcome:

1. The receiver could not pick up the low-power transmitter unless the two were right next to each other.
2. A larger antenna would improve reception, but I didn’t want to have a large piece of wire hanging off the back of the radio since I planned on placing it in the living room.
3. Adding an amplifier to the transmitter would improve reception, but would make the circuit more complex; more importantly, I would have to be careful about the FCC’s part 15 rules.
4. I didn’t want to put a computer in the living room – most of the ones that I have laying around are noisy, so it would be best to keep the audio source (computer) in the basement.

I needed a way of relaying (preferably legally, cheaply and simply) the audio from the computer in the basement up to the AM transmitter located just behind the receiver. After considering several possibilities, I finally settled on using a baby monitor set to do the relay. My wife picked up this set from Target, which sells for $20, claims a 600+ foot range and operates on 49MHz:

Safety 1st Baby Monitors

They aren’t Hi-Fi by any means, but neither is the Crosley. Besides, $20 for a TX/RX pair is about as cheap as it gets. The transmitter was easily modified to accept a direct audio line in by replacing the electret microphone with a 20dB attenuator and 1/8″ stereo jack; I simply drilled out the mic hole to accommodate the line input jack:

Relay transmitter with 20dB attenuator

Relay transmitter exterior view

For the receiver, I just replaced the speaker with a 1/8″ line out jack:

Relay receiver with line out jack

Relay receiver exterior view

Initially I tried placing the AM transmitter in the relay receiver enclosure and powering them both from the same 9v wall wart, but this resulted in nothing but heavy static feeding into the AM transmitter. Instead, I enclosed the AM transmitter in a separate case and powered it off an external battery; given that the AM transmitter draws a relatively low 50mA of current, this was an acceptable compromise:

AM transmitter assembled in case

The primary audio source for the transmitter is my PC, but I also wanted to be able to re-transmit CD, cassette and FM radio programs as well. I’m using an old Pioneer SX-2300 stereo to manage the audio sources; the Pioneer, cassette deck and CD player were all pulled from the dumpster:

Transmitting station

Here you can see the audio output of the baby monitor connected to the audio input of the AM transmitter, and the RF output of the AM transmitter connected to the antenna input of the Crosley. Radio, “the way it used to be” (more or less):

Get the Flash Player to see this player.

Cabinet Front View

Cabinet Top View

Inside The Cabinet

Underneath the layer of off-white paint was another layer of baby blue paint; even the knobs and brass had been painted over. After much sanding, and scraping, I finally removed all of the paint from the wood. I was able to chip the paint off the brass with a small screwdriver and then shine it up with brasso. The brass screws for the dial plate had to be replaced, but a replacement set was easily found at Lowe’s. The internal chassis was also cleaned up with a touch of brasso and a can of compressed air.

After applying a couple coats of wood stain and re-affixing the brass dial plate, the cabinet was looking much better:

Cabinet After Wood Finish And Brasso

I found some replacement grille cloth from Antique Radio Grille Cloth. It only cost $7 and was an exact match for the grille cloth that was being replaced (although I don’t believe that it was the original pattern used by Crosley). Per their instructions, I ironed the cloth out, then fixed it in place with spray adhesive and a staple gun. With the grille cloth in place, the internal chassis could be placed back in the cabinet:

Cabinet With New Grille Cloth And Chassis In Place

All that was left now were the knobs, which had to be replaced. Unfortunately, antique radio knobs are not cheap; I found some original replacement knobs for this model radio, but they were selling for $30 a piece and were not a complete set. Instead, I purchased a set of four replica wooden knobs for $5 each from Radio Daze which I think look even better than the original plastic knobs that the set came with. After a quick wipe-down, it was ready for display in living room:

The Crosley 516

Way cooler than it’s faux counterparts (and a fraction of the price)!