Incomplete project We are not sure but guessing it to be an audio/speech amplifier/compressor for higher audio gain to your transmitter ???? Has 1/4" jack and plug (in and out?) has a bypass switch too. Has heathkit DX-100 transformers on a chasis with various other parts as shown. History unknown- came from a hamfest. Wiring looks fairly complete except the "threshold" pot looks to either never been put in or was scavenged. Includes 3 Heathkit transformers: 54-31 power 51-23 audio 46-11 choke all look to have been painted grey but could be repainted or cleaned off back to black color underneath. Nice ceramic socket All sold as is, all sales final, however we will guarantee the power transformer to be good as it is the most valuable component. Buy it for the transformers or buy it to figure out and complete it.