{"product_id":"1-tested-1920s-gold-seal-gsx-20-tube-6-volt-hy-mu-equivalent-daven-mu-20","title":"(1) Tested 1920s Gold Seal GSX-20 Tube 6 Volt Hy Mu Equivalent Daven MU-20","description":"\u003cdiv style=\"text-align: center;\"\u003e\n\u003cmeta charset=\"utf-8\"\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cspan style=\"font-family: Arial;\"\u003e(1) Tested 1920s Gold Seal GSX-20 \"Hy Mu\" (High Gain) Triode Tube.\u003c\/span\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cspan style=\"font-family: Arial;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cspan style=\"font-family: Arial;\"\u003ePlease note that the this is \u003ci\u003e\u003cstrong\u003eNOT\u003c\/strong\u003e\u003c\/i\u003e a type 20 tube. The '20' refers to the gain rating.\u003c\/span\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cspan style=\"font-family: Arial;\"\u003eThis is a very specialized and rare 6 volt resistance coupled high gain tube similar to a Daven MU-20 tube.\u003c\/span\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan\u003eEarly shaped glass envelope with the both original labels still present (front and back).\u003c\/span\u003e\u003cspan\u003e\u003cspan style=\"font-family: Arial;\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cspan style=\"font-family: Arial;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan\u003e\u003cspan style=\"font-family: Arial;\"\u003eSince no known test settings exist for this particular tube it was tested with the settings for a type 40 tube with the filament setting at 6 volts and a bias of 32. This gives a general idea of its strength and condition but is far from perfectly accurate - see test results below.\u003c\/span\u003e\u003c\/span\u003e\u003cspan\u003e\u003cspan style=\"font-family: Arial;\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\u003cspan\u003eTested on a calibrated Hickok TV-10 military tube tester\u003cb\u003e\u003c\/b\u003e with \u003cb\u003eno shorts\u003c\/b\u003e and \u003cb\u003eno leaks\u003c\/b\u003e with the following results:\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eGm Test = 575 micromhos\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eMinimum pass\/good = 125\u003c\/span\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cb\u003e~ Please view all 5 photos ~\u003c\/b\u003e\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Classic Currents","offers":[{"title":"Default Title","offer_id":48327019528447,"sku":null,"price":134.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0788\/5999\/3343\/files\/IMG_0389.jpg?v=1774377356","url":"https:\/\/classiccurrents.com\/products\/1-tested-1920s-gold-seal-gsx-20-tube-6-volt-hy-mu-equivalent-daven-mu-20","provider":"Classic Currents","version":"1.0","type":"link"}