[Elecraft] K2: KPA 100 Capacitor Specification?

[Geoffrey Mackenzie-Kennedy]

John,

If the voltage rating of these relay coil bypass caps is somehow being 
exceeded in your shipboard installation causing the caps to fail, and if you 
cannot find suitable higher DC voltage rated leaded replacements, you might 
like to consider using SMD (chip) capacitors instead.

AVX include in their product line of multilayer ceramic SMD capacitors for 
low frequency use, as opposed to microwave rated devices, .01uF  100 VDC 
caps in both 0805 and 1206 sizes, and 0.015 uF caps rated at 500 and 600 VDC 
in 1206 packages.

I have no financial interest in AVX, but do use their microwave rated 
capacitors.

73,
Geoff
GM4ESD


Don Wilhelm wrote on Friday, April 03, 2009 at 3:29 PM.

> John,
>
> I have never found one of those caps shorted, and I believe the DC
> rating on them is 50 volts, so they should have an adequate safety
> margin since they are used in a 12 volt DC circuit.
> I have trouble imagining a condition that would cause them to fail, but
> then I recall that your 'shipboard' operation is unusual and may
> introduce 'perils' that I cannot imagine.
> There would be no harm in replacing those capacitors with 100 volt caps
> *if* you can get them to fit physically.  You may have to solder them
> flat against the bottom of the board.  The other problem is that 100
> volt caps may be difficult to procure with 0.1 inch lead spacing and you
> may have to get creative to substitute caps with 0.2 inch lead spacing.
>
> 73,
> Don W3FPR