[Elecraft] KPA500 SWR Calibration

[Bob McGraw K4TAX]

I've been doing a bit of looking at SWR indications.  The numbers are 
factually frightful.   With 100 watts forward power and 0.25 watts 
reflected the SWR is 1.1:1.    And with 500 watts forward and 1.25 watts 
reflected the SWR is still 1.1:1.    I believe that says 0.25% of the 
power is being reflected.   But I ask, what is the SWR at the antenna 
feed point?  It is certainly higher than at the transmitter due to feed 
line losses.

In using 100 ft of RG-213 at 14 MHz, the matched line loss is 0.780 
dB.   With a 1.1:1 SWR the total loss goes up by 0.001 dB and the SWR at 
the Load is 1.12:1 where Z = 48.25 -j4.63 ohms.

All of this is just "killer math" and makes absolutely no difference 
except to the operator that expects an SWR of 1.0:1 all the time.

73

Bob, K4TAX


> http://elecraft.365791.n2.nabble.com/K3-SWR-Numerical-Indication-td7643839.html#a7643944 
>
>
>