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Nuvistor · 22nd Aug 2019, 10:01 am

Thanks Lawrence.

The IF amplifier AGC circuit is interesting, well to me any way, the second diode in the UBF89 is connected across the AGC line, in earlier circuits see U195, there was a resistor (10M ohm) from HT to the anode of that diode to allow delayed AGC.

Perhaps Ekco found that although not quite a good a delay circuit they could save the cost of a resistor.

22nd Aug 2019, 10:01 am	#5
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Understanding Ekco U332 schematic. Thanks Lawrence. The IF amplifier AGC circuit is interesting, well to me any way, the second diode in the UBF89 is connected across the AGC line, in earlier circuits see U195, there was a resistor (10M ohm) from HT to the anode of that diode to allow delayed AGC. Perhaps Ekco found that although not quite a good a delay circuit they could save the cost of a resistor. __________________ Frank