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MODIFIED END FED 155 FT AND 9 TO 1 UNUN

 

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*

*Here is my? "MODIFIED"? 155 FT END-FED? wire WITH?? 9:1?? UNUN (Palomar Engineering) ? and? T-network? CLC tuner in shack*

*Lowest? SWR? set to around 7100 kHz? with a RETURN LOSS? of about?? +25dB ? (plotted as a negative to match SWR graph)
*

*Set up to tune easily on the digi end of fickle forty meters - ready for the Sunday MidAtlantic NBEMS on 7068 kHz at 10 AM EST*

*Can anyone explain the crazy? PHASE? graph with the dual phase changes?
*

*de k3eui*

wVV0ITjpskp6CHtZ.jpg
END FED 155 ft 9to1 UNUN and antenna tuner in shack.jpg

 

Barry,

The phase is just wrapping around 180 degrees.? Not to worry.

Jay KM4EP

On 2/23/2024 11:27 AM, Barry K3EUI wrote:

*
*

*Here is my? "MODIFIED"? 155 FT END-FED? wire WITH?? 9:1?? UNUN (Palomar Engineering) ? and? T-network? CLC tuner in shack*

*Lowest? SWR? set to around 7100 kHz? with a RETURN LOSS? of about?? +25dB ? (plotted as a negative to match SWR graph)
*

*Set up to tune easily on the digi end of fickle forty meters - ready for the Sunday MidAtlantic NBEMS on 7068 kHz at 10 AM EST*

*Can anyone explain the crazy? PHASE? graph with the dual phase changes?
*

*de k3eui*
 

It¡¯s like something make a second resonant point but not a real resonant point as other graphs don¡¯t show it.
Did you try to make the same mesurement without the tuner ?
 

Preferably look at the Smith. The phase jump is only a graphical effect of the fact that the phase passes beyond 180¡ã then below. On the Smith the curve will be continuous.
--
F1AMM
Fran?ois

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