Valvo RPY 86 , 87 , 88 , 89

Valvo was/is one of Philips' brand-names.

From a 1985 Mullard (another Philips brand) Quick Reference Guide:- No mention of RPY86 or 88, but '87 & '89 wavelength range 1.0 - 15 micrometres One lead connected only to envelope/case The adjacent lead (at 90 degrees) - Source The opposite lead (at 180 degrees) - Drain

No mention of supply voltage.

'87 - sensitive area 2mm X 1mm, responsivity 500V/W, noise power 1*10^-9 '89 - 2mm X 2mm, 250V/W, 2*10^-9 Both - frequency range 0.1Hz - 1kHz

Perhaps a Philips website, or even Google, would find more ...