[Elecraft] SWR Readings:Differences

[Don Wilhelm]

Mark,

Any transmission line will have an impedance transformation unless it is 
terminated in its characteristic impedance.
The other factor may be that you have some common mode current on the 
coax shield - that can skew SWR readings.

73,
Don W3FPR

On 9/2/2014 8:06 PM, pastormg2 at verizon.net wrote:
> Good Evening,
> This is Mark Griffin, KB3Z and I have some questions regarding the SWR readings I get at my tower versus what I get on my K3. I will give the SWR readings that I got at my tower for a 40 meter rotatable dipole at 55 feet.
>
> Tower:
>
> 7000  2.2
> 7025  1.8
> 7050  1.5
> 7075  1.3
> 7100  1.0
> 7125  1.1
> 7150  1.3
> 7175  1.6
> 7200  2.0
> 7225  2.2
>
> K3 Readings:
>
> 7000  3.5
>
> 7025  3.2
>
> 7050  2.9
>
> 7075  2.6
>
> 7100  2.4
>
> 7125  2.3
>
> 7150  2.4
>
> 7175  2.5
>
> 7200  2.6
> 7225  2.9
>
> What would cause such a big difference. The cable run from my antenna switch on the tower to my K3 is only an additional 75 feet. I am using RG-213 cable. Is there anyway that I can test the SWR reading that my K3 is giving me?
>
> Mark Griffin, KB3Z
>
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