HeathKit SB-303 Diode Specs

Discussion in 'Radio Circuits, Repair & Performance' started by W8RLC, Jan 22, 2020.

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  1. W8RLC

    W8RLC Ham Member QRZ Page

    "Perhaps I am misreading this, but doesn't the two drops of D14, bias the drops of Q22BE and Q24BE for a linear output."

    Yes, but as mentioned in the parts list it does provide some insight into the specs for the Stabistor.

    "P.S - The SW-717 manual shows the 56-61 as a 1 mA, 1.3V stabistor."
  2. W8RLC

    W8RLC Ham Member QRZ Page

    I just want to report the the 1N4830 is working well in the SB-303. The S-Meter there is no drift in the S-Meter at all.

    Thanks to all for the help.
  3. W8RLC

    W8RLC Ham Member QRZ Page

    The receiver rebuild is coming along. So far I have found several of the mica capacitors in the front-end to be out of tolerance so much that I could not get the circuits to peak during alignment. Replacing the caps resolved the issue.

    I updated the power supply to incorporate an EMI filter and modern IEC AC line cord socket. Also the circuit breaker and switch have been moved to the line side (hot) of the AC. The EMI filter is mounted just above AC Socket and towards the center of the rear panel.


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