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CHIEFTAIN valve radio 1950's.
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Return to top of page · Post #: 16 · Written at 2:05:28 PM on 10 January 2022.
	Johnny Location: Hobart, TAS Member since 31 July 2016 Member #: 1959 Postcount: 563
I have not got a circuit in front of me, but it sounds like the audio coupling capacitor. 1S5 being a detector/audio pre amp. And the 3V4 being the audio output valve. It would not be a electrolytic, I would use a 0.01 as suggested, which is only 1800pF the difference. I assume its between pin 5 and 6 of the valves mentioned. JJ

Return to top of page · Post #: 17 · Written at 7:51:12 PM on 10 January 2022.
	BringBackTheValve Location: Linton, VIC Member since 30 December 2016 Member #: 2028 Postcount: 472


Return to top of page · Post #: 18 · Written at 8:04:20 PM on 10 January 2022.
	BringBackTheValve Location: Linton, VIC Member since 30 December 2016 Member #: 2028 Postcount: 472
Keep in mind mechanical vibrations from tapping the cap will be transmitted into the detector and output valves via wiring and valve pins.

Return to top of page · Post #: 19 · Written at 9:37:00 PM on 10 January 2022.
	Ian Robertson Location: Belrose, NSW Member since 31 December 2015 Member #: 1844 Postcount: 2476
Microphonics are common in battery valves. Probably not significant. Check that you can get a "burp" when touching the "hot" end of the volume control with a screwdriver. If so, it's time to start measuring voltages voltages in the earlier stages. Your "new" 1R5 may be bad! They rarely survive a drop, even in the cardboard packet. A very delicate little valve.

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