GEC, MOV KT66's x 2 used, "Black Bottle" test strong - for vintage valve amplifiers-circa 1950/60's

Quad Set GEC Made in England, KT66 Audio Output Tetrodes - New Old Stock- Rare- circa 1960's

Your bidding on 2 x GEC, "Black Bottle" Valve Company,  KT66 Tetrodes, original, highly sought after Made in England, KT66's, Used, test strong. These original early GEC Valve Co are widely revered for their classic 'valve' sound. GEC "Black Bottle"  KT66's sound wonderful in vintage and more contemporary valve amplifiers. All Tested and guaranteed. 1- inch brown Bakelite bases base. Have been tested on my AVO 163 and guaranteed unconditionally under the following conditions Vf=6.3v, Vg=-15v, Va=250v, Vs=250v, a healthy 'New' tube should indicate Ip=80mA, gm=6.3mA/V. Test results; Tube1) Ip=97mA, gm=6.3mA/V, Tube2) Ip=82mA, gm=6.5 mA/V. Will ship anywhere the world at buyers expense.
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