Radio Cage
The Radio Cage is a voltage controlled radio reciever patched through a VCA/Ring Modulator and a Voltage Controlled Filter. The module also has a Voltage Controlled LFO.
The radio (mono) recieves AM, FM and Shortwave bands in both US and international frequencies.
The radio, VCA, and VCF can also each be used independently:
A radio direct out is available.
By turning the radio volume down at the mixer and using the EXT IN as input the VCA/VCF can be used seperately from the radio.
By using the FILTER BYPASS switch the VCA and VCF are unpatched. The VCA output is available at the OUT and its input is at EXT IN. Using the filter INPUT, the VCF is independent with output available from one of the 3 VCF outputs (LP, HP, BP). This also allows you to change the order of the patch to Radio -> VCF ->VCA.
Build notes
Construction is a panel PCB and a component PCB
Some resistors and a capacitor are on the panel PCB
The banana jack holes are plated but are not an electrical connection. Solder small wires to the trace pads from the jacks
IMPORTANT: The module needs to run on +/-12V. The AS3360 VCA chip can't be powered by -15V
Current build is Version 1.0
Download the schematic here: Radio Cage schematic
Download the BOM: Radio Cage BOM
Download part placement: Radio Cage part placement
Download trimming Instructions: Trimming
The module uses the Skyworks Si4825 chip for the radio. Here's the datasheet for the chip if you'd like more information
Notes
AM Antenna :
The antenna can be mounted internally if your enclosure allows it to work without interference. Space is provided on the component PCB for the antenna. In the prototype build I created footings with hot glue and cable tied the antenna to the board
Otherwise connect the AM antenna by stereo 1/8" jack
Instal capacitor laying down :
The capacitor on the panel PCB should lay down so it fits between boards
Band Switch :
The band switch needs to be fly-wire connected.