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AA5 hum
fenbach
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Posts: 138
Threads: 27
Joined: Dec 2016
City: portland, OR
#17

03-23-2019, 06:54 PM
has me baffled too, tom. the first electrolytic filter cap is 100uf. I tried doubling that. didn't help one bit. I don't see any hum on the scope after the 2nd or 3rd filter cap. but swapping out the transformer effectively eliminated the hum. go figure. for what it's worth, the replacement transformer is an old R/S audio transformer with various taps, for both input wattage and output impedance. I got the best sound quality with 0.62 watts in and 8 ohms out.
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Messages In This Thread
AA5 hum - by fenbach - 10-18-2018, 10:02 PM
RE: AA5 hum - by Radioroslyn - 10-18-2018, 10:28 PM
RE: AA5 hum - by Jayce - 10-18-2018, 11:05 PM
RE: AA5 hum - by Chas - 10-18-2018, 11:09 PM
RE: AA5 hum - by fenbach - 10-19-2018, 07:18 PM
RE: AA5 hum - by fenbach - 10-19-2018, 07:20 PM
RE: AA5 hum - by Chas - 10-19-2018, 11:04 PM
RE: AA5 hum - by gregb - 10-20-2018, 11:04 PM
RE: AA5 hum - by David - 11-04-2018, 02:20 PM
RE: AA5 hum - by Jayce - 11-04-2018, 08:24 PM
RE: AA5 hum - by 35Z5 - 11-05-2018, 08:57 AM
RE: AA5 hum - by morzh - 11-05-2018, 09:48 AM
RE: AA5 hum - by Squire - 11-08-2018, 12:12 AM
RE: AA5 hum - by fenbach - 03-16-2019, 10:12 PM
RE: AA5 hum - by Arran - 03-16-2019, 10:49 PM
RE: AA5 hum - by 35Z5 - 03-17-2019, 04:55 PM
RE: AA5 hum - by fenbach - 03-23-2019, 06:54 PM



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  1. The PHILCO Phorum
  2. Various and Sundry Categories
  3. Other Radios (Non-Philco)