4 RCA Cunningham Number Type 27 #27 Vacuum Tubes Lot Of Four

4 RCA Cunningham Number Type 27 #27 Vacuum Tubes Lot Of FourThese four RCA and Cunningham number type 27 tubes tested as low goodand good on our Paul Hart calibrated TV7 U. Transconductance readings are 25, 27, 32 and 36 where minimum (65%) is 25. 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

excellent flashing and copper support rods

rectangular mica spacers and anode radiators for cooler tube operation and longer life

This matched pair of Sylvania gray glass 12BY7 / 12BY7A tubes was tested on our Paul Hart-calibrated TV7/U for shorts

Transconductance measured (From left to right): 46 and 48 where minimum (65%) is 30

goal post getters

This performance was recorded in 1961 in Soviet-occupied Hungary

They have shoulder / ST bottles

8 milliamps' plate current and measured 2060 micromhos

they were forwarded to West Germany

on our Paul Hart-calibrated TV7/U where minimum is 23 and 100% is 35

new in box matched pair of Sylvania gray glass 7C5 tubse was tested on our Maxi-Matcher 2 with 400 volts on the plates and a bias of -36 volt for shorts

This lot of thirteen US-made 7F7 tested poorly and/or unevenly on our Paul Hart-calibrated TV7/U