London ILR Test Transmissions 1973
Although he seems completely unphased, this chap appears to be one of the first voices on Independent Local Radio (before you were allowed to call ILR 'commercial radio'). He is testing transmissions in London on 539m and 417m on AM - and also 95.8 MHz FM.
Back then, of course, AM was the 'lead waveband! FM radios were rarer - certainly in cars. Whilst 95.8 is familiar to this day for commercial radio, the AM wavelengths are not. They were temporary for Capital and LBC respectively. The then regulator, the IBA (which back then owned and maintained the transmitters) could not erect the transmission masts on a proper site so it made hurried arrangements by installing low power transmitters and hanging an aerial between two chimneys at the Lots Road power station.
Little wonder the new commercial stations quickly earnt the label 'Radio Clothesline'. All in all, another hurdle for a new commercial medium struggling to launch in recession and industrial strife.