[Elecraft] Internal K3 SWR vs Extermal SWR Meter

[Joel Black]

Mark,

You will get lots of responses to this. 99.9% of the folks on the 
Elecraft are more experienced and smarter than me.

I have a similar situation with a WM-2 wattmeter and my KX3. Here's how 
I stopped worrying about it:

1. I realized that I have to bypass the ATU in the KX3 to get a "good" 
reading on the WM-2.
2. Even after doing #1, I still have a 2W discrepancy between the KX3 
and the WM-2 (i.e. 5 W on the KX3 reads as 7 W on the WM-2). It varies 
at different bands and output power.
3. In my experience, wattmeters vary greatly and there is a deviation 
percentage that I think must be taken into account. I don't know what 
that amount is either. :)
4. When I use one, I am looking at an external wattmeter with a needle 
to get an instantaneous reading on reflected power. The needle is large 
and visible and I keep the meter in REV when I use it. This leads to an 
experience I had several years ago in a class on SCADA radios. The 
discussion of the Bird 43 wattmeter came up:

I was once told that a Bird 43 wattmeter has about a 10 - 20% error rate 
(I forget the exact number). I told the guy I didn't care as long as it 
was the same inaccuracy when looking in both directions. I was looking 
for a *ratio*, not necessarily an output power. He looked at me like I 
was purple and had three eyes.

I try to simplify things. The purists and the engineers out there will 
in all likelihood disagree with what I've said. I am sure there are 
instances where what I say will not or cannot work. In my casual 
operation as an amateur for 20 years, this has worked for me. In my 
professional career as a telecomm tech doing PMs and trouble-shooting on 
37, 450, and 900 MHz radios for almost as long, this has worked.

As with anything else I may say, this is just my experience. Your 
mileage may vary greatly...

73,
Joel - W4JBB

On 11/17/13, 11:01 AM, pastormg2 at verizon.net wrote:
> Good Morning, this is Mark Griffin and my call is KB3Z. I am having some real issues when it comes to getting a reliable SWR reading between my K3 and an external Wavenode Meter. I hooked up my hexbeam directly to the input Antenna 1 Connector of my K3 and got the following SWR readings in the SSB portion of the band.
>
> 20 Meters:1.1
> 17 Meters: 1.1
> 15 Meters: 1.8
> 12 Meters 2.7
> 10 Meters:1.4
>
> Yes, I know that 12 meters is high for some reason! But I than hooked up my antenna to the Wavenode coupler and then to the my Antenna 1 connector and notice the differences between the K3 and the Wavenode.
>
>                    K3                                  Wavenode
> 20 Meters 1.1                                    1.6
> 17 Meters 1.1                                    1.4
> 15 Meters 1.8                                    2.3
> 12 Meters 2.7                                    1.9
> 10 Meters 1.4                                    1.7
>
> Is anyone else out there experiencing the same issues between their K3 SWR and an external meter? Perhaps the wavenode coupler isn't good but I am so confused that I don't know what to do. Any assistance would be much appreciated.  Mark Griffin, KB3Z
>
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