12BV7 Matched Pair RCA Tubes NOS Test Black and similar items

This new old stock-testing, new in box Matched Pair RCA 12BV7 tubes was tested on my Hickok 800 for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured: Tube One: 6000 (RCA logo stenciled on glass with code BR.) Tube Two: 6000 (RCA logo stenciled on glass with code BR.) New is within half a standard deviation of 6500. Pair have black plates, same code of BR., and top halo getters. Tubes ships via United States Postal Service (USPS) Ground Advantage with tracking for domestic sales: Priority Mail is also an option for you. International sales ship via International Shipping service. Package weighs eight (8) ounces. Combined shipping always welcome on multiple orders. TUBES ARE GUARANTEED GOOD AND IN WORKING ORDER AT SHIPMENT. TRANSIT VIA POST CAN DAMAGE TUBES. THIS IS NO FAULT OF OURS BUT THE THIRD PARTY ENTITY THAT IS DELIVERING ITEM(S) TO YOU, I.E, USPS, UPS, FEDEX, YOUR NATIONAL CARRIER IF INTERNATIONAL, ETC. PLEASE INSURE THEM! WE CANNOT GUARANTEE FAILURES ON YOUR EQUIPMENT AFTER POWER UP AS THERE IS NO WAY TO ASCERTAIN HOW TUBES WILL INTERACT WITH YOUR ELECTRONICS; NOR IS THERE A WAY TO DETERMINE WHETHER THEY MAY HAVE FATAL FLAWS IN TUBES THEMSELVES! THESE ARE USED VACUUM TUBES AND TIME MAY HAVE TAKEN A TOLL ON THEM OVER THE MANY YEARS SINCE THEY WERE MANUFACTURED. WE CAN ONLY TEST FOR THE PARAMETERS MENTIONED ABOVE IN ONE OR MORE OF THE FOLLOWING EQUIPMENT WE USE FOR MEASURING: TV-7/U, JACKSON 648 MAXI MATCHER 2.