[Harc] SWR VS Resonance

[Howard, KB6NN]

Thanks Del.  You taught me well.  Way back when...

On 2/3/2021 12:36 PM, . via Harc wrote:
> Howard
> Resonancs and minimum SWR are, as you said, NOT the same. Also your comment on match boxes is CORRECT.
> The best way to tune an antenna SYSTEM is to use an old fashioned field strength meter. It measures the field strength as it is radiated.
> Meter should be OUTSIDE the "Near Field" effecr
> (I think > 3 wavelengths).
> Practical distance is far away as u can see it, or have smme on "give"  you the readinga.
> SUPER for tuning mobile antennas.
> Used 2 buy 2 mtr mobile antennas, replace antenna part with a piece of welding rod.
> Keyed on 123.5 mhz, read meter, trimmed 1 inch, keyed, read meter - continue until field strength no longer increases.
> Del W6KOZ
> 
> 
> 
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> On Wednesday, February 3, 2021 Howard, KB6NN via Harc <harc at humboldt-arc.org> wrote:
> 
> I have been trying to put into words why a dipole, resonant on a frequency we want to operate on may not show a 1:1 SWR.  From experience I know that such an antenna does not always show a low SWR, and that the placement of the antenna is important (height above ground, nearby objects, etc.) in determining the SWR of an otherwise resonant antenna.
> 
> Also important is the method of feeding the antenna and connecting it to the radio.  I also have been saying that SWR, when measured at the transceiver, is an indication of the match between the radio and the antenna system, not [just] the antenna itself - the antenna system includes anything from the antenna jack on the back of the radio all the way up to and including the antenna itself.
> 
> Another thing I say is that the matchboxes commonly called "antenna tuners" are matchboxes, not antenna tuners  They are impedance matching devices.  If the radio wants a 50 ohm load, the matchbox makes sure that, whatever the actual impedance of the load (antenna system), a match to 50 ohms is obtained.
> 
> I found an article that says it better than I can, and has examples: https://hamradioschool.com/good-swr-and-antenna-resonance/ <https://hamradioschool.com/good-swr-and-antenna-resonance/>
> 
> Thanks for reading,
> Howard
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> KB6NN
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