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Old 02-24-2017, 06:25 PM
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Hagstar Hagstar is offline
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Join Date: Jan 2016
Location: Vermont
Posts: 107
I do have a vexing issue still with the AGC that I don't understand. Originally I had no AGC voltage at all. After changing the two AGC diodes and both gate and amp transistors I do have voltage of 3-6 volts depending on AGC control setting. BUT there's an 8 volt zener that spills voltage into the tuner AGC line and I never get voltage that high. A high signal input from the test equip. increases voltage from 5.5 to 6 volts, that's it. BUT the schematic calls for around 5.5 normal with signal so I'm not sure what's right. The service manual for similar models says I should be able to get 2-14 volts....

Pulses controlling the AGC gate from the coil on the new flyback are weak on the positive side through the diode but strong on the negative side....
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Last edited by Hagstar; 02-24-2017 at 08:49 PM.
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