[Elecraft] Internal K3 SWR vs Extermal SWR Meter

[Ron D'Eau Claire]

Mark, the numbers you quoted look pretty typical for SWR meters. They are
*not* precision instruments, nor do they need to be even in commercial
applications. 

Within the range of error you reported, there will be no difference in how
your K3 and antenna work. 

Power measurements are no better. Even a much-admired Bird wattmeter with
freshly calibrated slugs can be off by 20% or more, depending upon several
factors, and I've not seen a freshly calibrated slug since the last time I
worked in a laboratory. 

So it's just as likely the difference you see is the result of external
wattmeter calibration as it is the K3's wattmeter calibration. Any procedure
for "synching" them is just as likely to make one of them less accurate that
it is now. 

I presume that you are using a good 50 ohm dummy load to compare readings
with the KAT3 in bypass, and that you have run the wattmeter calibration
procedure in the K3 Owner's manual.

73, Ron AC7AC


 

-----Original Message-----

John, the problem is that I don't have one of these. But thanks for the
suggestion. One thing I have not tried is hooking up my antenna and external
wattmeter coupler with Antenna 2 instead of Antenna 1. I am anxious to find
out if I get the same readings with #2 as I did with #1. I guess I am rather
perplexed at the thought that there is such a variance between the K3
wattmeter vs an external wattmeter. Especially, when I connected the coupler
to the antenna #1 with a plug and then attached the antenna coax to the
coupler. It's a shame that the K3 does not have a way of synching up the
internal wattmeter with an external wattmeter. Hopefully somebody from
elecraft will read this email and make a comment on it. Thanks to all with
their responses. Mark Griffin, KB3Z
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