RCA Number Type 38 #38 Vacuum Tube Valve Engraved Base Shoulder Shape NOS NIB 1st Quarter BW01 They have engraved / hot-stamped

They have engraved / hot-stamped bases

This matched pair of RCA black plate 5763 tubes were tested on our Paul Hart-calibrated TV7/U for shorts

It has 93S6 provenance/date codes

These four US-made 7A7 tubes tested as follows on our Paul Hart-calibrated TV7/U where minimum (65%) is 44 and 100% is 68:

Transconductance measured (From left to right): 41

RCA Number Type 38 #38 Vacuum Tube Valve Engraved Base Shoulder Shape NOS NIB 1st Quarter BW01 They have engraved / hot-stampedThis new old stock, new in box RCA number type #38 tube tested to spec on our Paul Hart calibrated TV7 U. BECAUSE OF THE BIZARRE, INTRUSIVE AND DRACONIAN GERMAN PACKAGING REGULATIONS AND THE SEVERE FINES AND PRIVACY INTRUSIONS ASSOCIATED WITH THEM WE NO LONGER SHIP TO GERMAN ADDRESSES. WE WILL HAPPILY SEND YOUR PACKAGE TO A NEIGHBORING COUNTRY OR MAKE SUITABLE ARRANGEMENTS. IN 2021 WE PURCHASED 150,000 VACUUM TUBES. IF IT'S NOT LISTED, WE PROBABLY