[Amps] peak voltage rating for load cap

Peter Voelpel dj7ww at t-online.de
Sat Aug 19 09:29:38 EDT 2017

Let´s say the SWR is 3 then the load might be 150 ohms.
The peak voltage across the load capacitor will be 775V at 2KW.
That is sqrt3 higher then at SWR1.


-----Original Message-----
From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of Joe Subich,

That will give you average (RMS) voltage with SWR = 1:1.  For peak
voltage, multiply by 1.414 (peak voltage of a sine wave):  316 * 1.414
= 447 V.

> Your 1200V capacitor will do the job with adequate headroom., when
> your system is all tuned and matched.
Multiply the peak voltage by the SWR for worst case peak voltage if
the voltage node occurs on the capacitor - 316 * 1.414 * 3 = 1340V.
A 1200 volt rated capacitor will be marginal in a *system* allowing
for a maximum SWR of 3:1 at 2 KW - it will be barely adequate when
the system is designed for 1500 W (1166 V).

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