Svetlana 6550 6550C 6P27P Output Tube NOS-Testing 6AS8 Nonal T60 Tube Four: 34/2240 where new/nominal

Tube Four: 34/2240 where new/nominal is within one standard deviation of 1900

each having four stamped crosses: two upside-down and two right-side up

new in box Realistic (Radio Shack) Gold Clad 6BL8 / ECF80 tube tested to spec on our Paul Hart-calibrated TV7/U

The spine is in fine shape and the book has no loose pages

These matched pair of engraved-base

Svetlana 6550 6550C 6P27P Output Tube NOS-Testing 6AS8 Nonal T60 Tube Four: 34/2240 where new/nominalThis new old stock testing Svetlana 6550C 6P27 perforated plate output tube was tested on our Maxi Matcher 2 with 400 volts on the plates and a bias of 48 volts for shorts, gas and transconductance. There were no shorts or gas. Plate current measured 67. 2 milliamps with a transconductance of 5640 micromhos. (New US made 6550s typically test with plate current from the low 20s to mid 40s with transconductance from 3500 micromhos or so.) It has