How to Add Alexa, Amazon Dot, Google Home, Apple Homepod Smartspeaker to Old Vintage Antique Tube Radio
How to Add Alexa, Amazon Dot, Google Home, Apple Homepod Smartspeaker to Old Vintage Antique Tube Radio
Smartspeaker technology is a great way to upcycle and repurpose your old antique vacuum tube radio for modern uses. You can use smart speaker to order pizza, select a music playlist, find a stock price, or find out the airspeed velocity of an unladen swallow.
Any old radio will do.
I repeat.
Any old radio will do.
(Yes, I'm sure)
As an example, this General Electric GE Model 574 is a perfect candidate for this type of upgrade. Plus, any modifications can be undone later on, more or less, as technology advances, and/or other technologies emerge.
This radio model makes for an easy conversion because it has a cardboard backing board, metal chassis featuring point-to-point wiring, and it sounds great.
You should disassemble the chassis, clock, from the radio cabinet and clean thoroughly. Make sure filter capacitors, passives, tubes all check out. I will not be covering how to perform radio repair in this article. I am assuming you are starting with a working radio.
This particular radio model has a RCA jack in back but I find the jack depth is not sufficient for modern plugs. So, the plug doesn't stay plugged in. For this reason, I prefer to install a direct connection from the internal circuit to the Bluetooth receiver.
Basically, the Bluetooth receiver signal is fed into the amplifier circuit before the amplifier stage. This way you can still modulate the audio volume coming from the radio as well as from the Smart speaker itself.
Remove the wire that connects to the right lead of the potentiometer (shaft pointing towards you). There should be only three leads.
Solder a wire to the right most tab. I use a red wire because this is where the signal comes out whether it be radio playing mode or Smartspeaker playing mode.
I solder a black wire to the wires that were originally connected to the right most tab of the potentiometer.
I run these wires through the chassis to the top.
You will need to cut a hole for DPDT toggle switch. The hole for the switch is probably the only change that is not reversible. It is for that reason, I prefer to upgrade radios with a cardboard backing board.
After you install the switch, you connect the red wire to the center tab of the DPDT toggle switch. The black wire connects one of the end tabs. The switch position that closes this circuit is for playing the radio.
The other tab of the DPDT switch connects to the Smartspeaker input via cable that has two male 3.5mm plugs. Clip off one end of the cable and remove approx 2" sheathing. There should be three wires; red, black, white.
Strip the red, black, and white inner insulation about 1". Connect red and black wires of cable to the other remaining tab of DPDT switch. Color of wires in 3.5mm cables may vary. Sometimes, the three wire colors are yellow, red, and green. Regardless of color, one wire is the cable ground wire and the other two are cable signal wires. The cable end has three sections. The outer sections are for signal connection. The inner section that is closest to the plug is the cable ground. Solder the cable ground wire to the ground of the radio. A .01 uF capacitor between cable signal tab and ground would be a good idea to isolate transient potentially damaging voltages from ruining your Smart speaker and/or radio.
Wrap the wire nut so it doesn't flop around.
Reassemble carefully so loose wires are not interfering with any mechanical operations and not touching any tubes.
Connect 3.5mm cable plug into Smartspeaker jack. Pair with your wifi and you're all set!
It is true the Smartspeaker device is external to the radio and is powered separately through a smart charger as opposed to the radio mains power. Incorporating the Smartspeaker into the radio chassis, and connecting Smartspeaker power through a transformer is easy to do, but I find there are problems with interference.