Thread: motorola 19k2
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Old 02-12-2015, 12:16 AM
EdKozk2 EdKozk2 is offline
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Join Date: Mar 2014
Location: Elkhorn, WI
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Make sure you have your focus control in the fully ccw position when you take your voltage readings on the 12au7 and 6au6 sound I.F tubes.Your cathode supply voltage
on both those tubes is +115vdc and the plate supply voltage is +265. Your cathode resistors of 220 ohms only drop about 1.5 to 2 volts. Check R-60 the 22k resistor connected to pin 5 of V12 and ground, that forms the final leg of your power supply bleeder, 115 volt to ground. An open or way off spec 22k resistor could through the readings off. The sync clipper is a DC coupled to the sync amp. The sam's also notes that the pin voltage readings are between various supply voltage points, e.i. 115 and pin 6 of the 12au7. A shorted capacitor would tend to burn a resistor ,a transformer,and blow itself up even.
Ed
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