Sudipta, It depends. Is it labeled GR80 or is it GR-80? Bob - N0DGN USA On 12/22/2013 8:47 PM, Sudipta Ghose wrote: > Hi all! > Greetings from India. > I need specs for GR80 tubes. I have received some liberal supply. > Wonder if I have any use of them. > 73 > Sudipta Ghose VU3TKG