The 1SV308 is covered by this compact 69 KB PDF, filed among schematics. 1SV is the JIS diode designation that Toshiba applies to its varactor range, used where capacitance must change with a control voltage. The name holds only the part number. Read it in any PDF viewer for the package drawing, ratings and capacitance curve before swapping a part in an oscillator or tuner. Match the marking code on the board component first, as similar SMD diodes are easily confused.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.