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AES type of Battery Eliminator has hum in B+
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Hello All,
I have built a battery eliminator using the most popular AES K101a. Using plans and all the AES parts  ordered from their parts list, except for the Q2 transistor, obtained from eBay.  Not wanting to have the circuitry on a board, I instead built this project on perf boards and placed it inside an antique jewelry box.  This power supply seems to work well and hold up to its voltage duties and regulation.  The problem is, it provides a pretty good 60 cycle hum.  In studying their only DC filter tank, a 50 UF electrolytic and no inductors so its not surprising to me to hear hum in the B+
 I noticed that many collectors have built this exact battery eliminator and it is a much discussed subject in the forums.  I have searched about the hum though and come up with nothing.  So I am wondering how other people's projects worked in regard to a DC ripple and if anyone has ever modified it from the original design to eliminate hum?
  I am planning to provide a more sophisticated filter structure, like 2 filter condensers and a choke.  If anyone has any ideas I would like to hear.
Bruce B


Messages In This Thread
AES type of Battery Eliminator has hum in B+ - by Bruce B - 03-30-2025, 09:27 PM
SMPS for tube radios - by toptip - 12-06-2025, 09:22 PM



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