Mullard 61SV Vacuum Tube Photo Tube NOS NIB 6550 This is a late-40s pressing

This is a late-40s pressing with some scratches and moderate surface noise

These tubes have anode radiators for cooler operation and longer tube life

46 and 54 where minimum (65%) is 45

Tube Two: 22

new in box Trigon UCH81 tube tested to spec on our Paul Hart-calibrated TV7/U

Mullard 61SV Vacuum Tube Photo Tube NOS NIB 6550 This is a late-40s pressingThis new old stock, new in box Mullard 61SV IR sensitive lead Sulphide photoconductive cell tested to spec on our Paul Hart calibrated TV7 U. It has 93S6 provenance date codes. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY SISTER SITE "LOWTECHTWOO" AND OR CALL OR TEXT US AT 202 372 6931 IF YOU DO NOT SEE WHAT YOU NEED OR HAVE ANY QUESTIONS. 1. MOST FORMS OF SHIPPING EXCEPT MEDIA MAIL ARE