Any ideas on this 4 pin vactorol, think it says VTL JA2
(https://s14.postimg.org/w55rg66tp/61875_D0_A-6_F4_E-4297-9_A36-_C3_A21_B078941.jpg) (https://postimg.org/image/w55rg66tp/)
(https://s14.postimg.org/syb7wk1t9/92_B11_CBE-0556-4_BE5-_BEDA-42_A24_F6_B2_D73.jpg) (https://postimg.org/image/syb7wk1t9/)
(https://s14.postimg.org/81ezrvw2l/F03_C8591-5_C98-48_D9-810_A-8343771_ECF44.jpg) (https://postimg.org/image/81ezrvw2l/)
I know vactech is the company that came up with the term "Vactrol" back in the late 60s, so I'd wager thats a seriously old school representative. Can't find much on the specifics of that part though.
edit: Could be a "VTL-9A2", based on an incandescent lamp. PDF is a bit blurry but would suggest an off resistance of 10meg, on resistance of ...60 ohms? That seems off, but again, hard to read data sheet.
http://datasheet.datasheetarchive.com/originals/distributors/Datasheets-111/DSAP0026836.pdf
Neat, if he is correct and it is incandesscent then it should probably get hot while it's operational.
I experemented with 3mm incandescent lights instead of leds and gave up on it cause they got way to hot.
Must be VTL9A2 then