Quantity   Component name
2 × XR2206 function generator kit These inexpensive kits are available for ~$6-$9 on eBay, Ali Express and elsewhere
1 × 15 watt stereo amplifier board. Also available for cheap on eBay and elsewhere. The bigger the CRT, the more watts required
1 × Cathode-ray tube display This can be a small television, computer monitor, security monitor.