TV7D/U Test SEVEN(7) TUBES RARE 1940's RCA ENG. LAB DEV. 6AS7G Twin Triodes

Description: This eBay Lot sale is for SEVEN(7) VACUUM TUBESTYPE 6AS7G This is a very long description with FULL test resultsplease read it before you buy it now. Always happyto answer any questions fast via eBay 'contact seller'. QUANTITY Six (6) RARE 1940's RCA Engineering Laboratory Development Prototype Military 6AS7G (ST-16+ Glass, 8-pin Octal base) Tubes.+ as a bonus to the buyer we are including a QUANTITY(1) RCA 1952 6AS7G tube just as strongly tested as these 6.So you will receive SEVEN(7) vintage 6AS7G tubes. Why are these 6 of 7 tubes rare? These 6 RCA tubes were prototype 6AS7Gtubes supplied to the US Military for Engineering Laboratory Development,RCA registered the 6ASG7 tube with Data Sheet Nov. 6 1945 and on Jan. 10 1946it was officially registered by Electron Tube registration List 463.All 6 tubes do not have glass etching, no tube type designation or markings on the baseother than the RCA Laboratory development sticker shown in pics. This set of 6tubes were most probably manufactured in 1944 to early 1945. Condition: ALL tested Strong Gm & mA. Clean Pins, Glass and locator, plug in a play condition. Very Lightly Used Military Surplus Engineering Laboratory Development Tubes found out of boxes as shown. TV7D/U Tested Strong Transconductance(Gm)& mA Plate Current emissions against RCA factory data sheet (RCA 6AS7-G). The Single 1952 RCA 6AS7G tube tested NOS+ strong. WE have marked each tube on the glass with the test results in black easily removable sharpeewith water or glass cleaner and paper towel. You will receive a full printed copy of this detaileddescription with details of test results in the box shipped. 6AS7G Twin TRIODE Audio Frequency Power Tubes for your Single Ended or Push-PullAudio Amplifier or Tube type Power Supply.All Tubes tested Strong for Gm & mA. (full test results below) -Made in USA -Thoriated Tungsten Anthracite Black plates-Constructed under Military Specifications for Laboratory Test & Development, designed and improved to be Hard-Waring, long hour life, shock-resistant for mobile and avionic Battlefield use.- 6AS7-G Tube (ST-16 Shaped Glass) : Glass envelope is a little taller than an early RCA 1952 6AS7G (ST-16)(see pics) that you will receive in this tube lot.- Filaments : Vf: 6.3V. If: 2.5 Amperes Current is a low Mu=2 Power Audio Frequency Twin Triode running in Class A1 with lowest THD at 135V Plate Supply Voltage. - The 6AS7-G tube is/was also used as a "Series Regulator in Controlled DC Power Supplies" and as a DC Amplifier at 250V Plate Supply Volts(max) at 13watts max. plate dissipation. - Also used in CRT Scopes and TV Service as a Booster Scanner 525-line 30-frame systems. Our test set : Recent Dan Nelson calibrated (07/24/2023), restored and upgraded TV7D/U with Digital Meter reading Transconductance in uMhos (Gm) and mA (Anode Plate Current). Passed Calibration re-check on 01/06/2024 TV7 TEST SETTINGS: 6AS7 6.3 HY4-5062 100 - C 3 36 Triode #1. 6AS7 6.3 HY1-2035 100 - C 3 36 Triode #2. Test results : NO Shorts, No Leakage, No Gas, No Apparent Micro-Phonics detectedReference: Minimum good TV7 meter reading of 36. Test results shown in pics. Tube 1: ('label inked 'A4475, top spacer inside glass inked '834-6' ') Gm= 75.9 / 74.7 = 3,795 / 3,735 uMhos Transconductance @ 101.5 / 105.6 mA Plate Current emissions Tube 2: ('label inked 'A4476', top spacer inside glass inked '823-6' ) Gm = 75.2 / 75.8 = 3,760 / 3,790 uMhos Transconductance @ 102.5 / 106.9 mA Plate Current emissions Tube 3: ('label inked 'A4471', top spacer inside glass inked '826-6' ) Gm= 77.4 / 78.2 = 3,870 / 3,910 uMhos Transconductance @ 107.0 / 101.3 mA Plate Current emissions Tube 4: (' partial label , top spacer inside glass inked '803-6') Gm= 74.8 / 77.6 = 3,740 / 3,880 uMhos Transconductance @ 113.7 / 113.5 mA Plate Current emissions Tube 5: (' label missing', top spacer inside glass inked '776-6') Gm = 77.3 / 74.6 = 3,865 / 3,730 uMhos Transconductance @ 118.4 / 129.6 mA Plate Current emissions Tube 6: (' label missing', top spacer inside glass inked '808-6') (note - this tube has a small sliver chip of glass inside the tube envelope, but tests strong with no shorts) Gm = 75.9 / 75.8 = 3,795 / 3,790 uMhos Transconductance @ 95.9 / 112.2 mA Plate Current emissions Tube 7: RCA '2 09' 9th week 1952 production version 6AS7G -tested NOS+ Gm = 74.4 / 72.3 = 3,720 / 3,615 uMhos Transconductance @ 135.1 / 138.1 mA Plate Current emissions For Reference: ( see pics for both RCA and Tung-Sol 6AS7-G factory Engineering data sheets)RCA & Tung-Sol Data Sheet Bogey Spec (100% or when Factory New) Typical Operating Characteristics as a Power Audio Amplifier Running in Class A1from RCA Factory = 7000/7000 micromhos @ 125/125 mA +/- 10% RCA Factory Plate matching for 6AS7-G Twin Triodes would pass RCA QA inspectionfor shipment if the plates matched at 10% or less. TV7D/U Settings: (Notes: Minimum Good = 36 = 1,800 uMhos Transconductance ( Gm) ) 6AS7 6.3 HY4-5062 100 - C 3 36 Triode #1. 6AS7 6.3 HY1-2035 100 - C 3 36 Triode #2. with these settings the TV7D/U applies the following voltages to the tube under test:__135_Volts Supply plate, __130_Volts screen, ___-40___Volts bias Control Grid ( bias dial set at 100 )

Price: 199.95 USD

Location: Miami, Florida

End Time: 2024-12-25T15:02:31.000Z

Shipping Cost: N/A USD