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Old October 8th 07, 08:44 PM posted to rec.radio.amateur.boatanchors
Chuck Harris Chuck Harris is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 270
Default Tantalum capacitor value?

Hank Zoeller wrote:
I need to replace some capacitors in a boat anchor receiver. These
caps are across the power supply rails on a logic circuit board. They
are marked "227 +10K". My interpretation of that is 220 MF. at 10 VDC
with a 10% tolerance. Does my interpretation sound correct?

Any suggestions for a replacement? If I use tantalums will I be doing
this again in 20 years?

Thanks,


Tantalums are quite reliable if you choose them correctly.

The usual causes of short life are the magnitude of applied voltage, and
charge/discharge current. As a rule of thumb, pick a capacitor that has a
voltage rating that is a minimum of 2 times the maximum voltage the capacitor
will ever see, and you should be ok.

High charge and discharge currents can sometimes be solved by using a series
resistor between the source that you are filtering, and the capacitor that
is doing the filtering.

Applying reverse polarity will cause an extremely short life.

-Chuck