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Old 01-12-2008, 06:20   #6
mvs sarma
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Join Date: Apr 2007
Location: Hyderabad, India
Posts: 220
Quote:
Originally Posted by Digger
Today, for the first time I enjoyed Beethoven' s 9th from DW on the Morphy Richards in the livingroom with the built-in telescopic antenna running on 230 VAC with the AC power supply which came with the receiver!

If you take a hammer and chisel, break the cover of the AC supply apart, solder 4 pcs of 10 nF capacitors across the rectifier diodes, then it works! All the horrible buzz and noise from the power adapter disappears!

Later in the evening I heard AIR Khampur, Langenberg and RAI on 846 kHz without problems. Why can't they think of this at the manufacturers???? A lousy AC adapter ruins the reception totally...
You have rightly pointed. In fact we used capacitors across each diode,instead of searching where to keep, as it depended on characteristics of diodes.
These LOUSY ones and their manufacturers aim at cheapness, and nothing more.The Transformers become too hot as they would use low quantity and/or quality of core.

May I add another point that most adopters or wall warts what ever they are called, can well have regulators inside (linear though, as switching supplies are detrimental for radio Rx use.) and give a good stabilization and as on date adding a regulator for say 250 or 500mA load is not costly and it would help for good health of most equipment.

They can better stop making orthodox unregulated junk.
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Regards,
Sarma
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Elektor SDR 5/07- Elektor Preselektor - Miniwhip Antenna of PA0RDT
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