[Heath] Replacement Capacitor Needed

[G3OOU at aol.com]

Hi Doug
 
I think that you are referring to C59 across the high voltage secondary of  
mains transformer T-1. This capacitor must have a voltage rating in excess 
of  1.414 times the rms voltage across it plus an allowance for the mains 
supply to  rise to its maximum tolerance and then some additional contingency. 
The  1600v rating seems very reasonable to me.
 
You can get high voltage ceramic capacitors and use two or three in  
parallel to make the total capacitance required.
 
I assume that the original capacitor was intended to reduce spikes from the 
 mains as it is a large value and probably the wrong type of construction 
for  high frequency RF decoupling.
 
73

Bob

Bob F Burns G3OOU,  G-QRP 6907, @BobFBurns
Crystal Palace Radio & Electronics Club: _www.g3oou.co.uk_ 
(http://www.g3oou.co.uk/) 
Technical web site: _www.qsl.net/g3oou  

 
In a message dated 25/10/2017 01:30:10 GMT Standard Time,  
dkdavies3 at gmail.com writes:

I need to replace a buffer capacitor in the power supply  rectifier circuit 
in an old HW-10 Shawnee I'm trying to restore.  It is a  paper cap, oil 
filled and the value is 0.047uf @1600 volts.  I can find a  0.047uf one but 
nothing rated at 1600 volts.  Is this a critical value or  can I replace it 
with a polypropylene one rated at 650 volts?  


Doug
VE7DRF



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