RCA 35x schematic question

Thread Starter

neospam

Joined Jan 13, 2020
110
Not sure if this is the right area to post this? what does the symbol that looks like a battery mean in the red circle? Says bias for gain data. I know some old radios have a small coin batteries in circuit for bias. the radio I am working on does not. appreciate if someone could explain the symbol in the circuit. thks
 

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Irving

Joined Jan 30, 2016
1,126
i dont think its a component. i think its a test measurement judging by the info about bias alongside. This is the Auto Gain Control (AGC) feedback and I suspect what its telling us is that the gain data (other measurements tabulated elsewhere) are taken when that is at -3v (or is forced to be -3v for testing other elements).
 

Thread Starter

neospam

Joined Jan 13, 2020
110
i dont think its a component. i think its a test measurement judging by the info about bias alongside. This is the Auto Gain Control (AGC) feedback and I suspect what its telling us is that the gain data (other measurements tabulated elsewhere) are taken when that is at -3v (or is forced to be -3v for testing other elements).
hi, thank you.. I think you are right. never seen this and was not sure. learning, working on a old radio that seems to have been worked on many times and did not work. thks
 
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