One boyhood hobby was shortwave listening of both broadcast and ham radio transissions and this did go go to school with me in various of necessity portable forms
This was a very specialized piece of kit designed for us during WW2 for SOE Agents behind German lines that came in two bits, this, the reciever and a transmitter that operated of a large battery as it used miniaturized tubes (Brit Eng: Valves).The Radio portion had a simple Tuned Radio Frequency (aka TRF) design rather then the better Superhet design for space reasons, a socket for the long wire antenna and earphones.
After all you didn't want "Jerry" hearing you!
Dad made a DC convertor that you clipped over the battery connectors so you could run it off the mains.
That hole on the upper right is the coil pack that sets the wavebands it recieves - you had two reversable pairs and because the tuning knob only had a one to a hundred scale you had a graph that converted that to actual frequencies on the inside of the battery unitThat long wire caused ahem "issues" with school grounds staff as it run from the dorm window to the nearest object to clip it on such as a pole or a tree as they seemed to think it was a saftey hazard even though I had a bright marker flag at the far end so it was visable.
One that sometimes came into school was the Soviet made Selena B 212 portable radio that did have extensive shortwave coverage but having its own telescopic antenna had less issues although you'd have the don't leave the pointy bit sticking out lecture.
That had a earphone socket and the ablity to connect to a tape recorder.
The home side of things could never of been in school although it make an appearence in May 1980 was the R 1155 radio reciever that also had a matching transmitter the T1154 and was fitted to the Lancaster aeroplanes and certain ships in a different version.The wavebands are selected from a knob on the left but the selection depended on model you had - mine covered from 75 Khz to 18 mhz, shipping to shortwave via Medium wave broadcast band radio.
It was modified to run off the mains and have a loudspeaker output rather then the leather headset with earphones and microphone built in.
By modern standards the electrical connectors would be condemned ease of reversal and carrying high voltages but, hey, I'm still living!
cc