Siemens Ribbed Plate 12AX7 ECC83 Vacuum Tube The Rainbow Strings but that was the fashion

but that was the fashion back in the 1940s

They measured 44 and 48 where minimum (65%) is 30

This hardcover book is in very good condition

new in box Tung-Sol 66BC8 tube tested to spec on our Paul Hart-calibrated TV7/U

Side Four is more like a 6

Siemens Ribbed Plate 12AX7 ECC83 Vacuum Tube The Rainbow Strings but that was the fashionThis Siemens ribbed plate 12AX7 ECC83 dual triode was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas and they measured as follows: It measured a perfectly balanced 44 44 where minimum (65%) is 32 32 and 100% is 49 49. It has copper support rods; 12MM ribbed plates; excellent flashing and an O getter with two rather than one supports. It has the requisite Siemens stamped metal plate just above