hello
to be sure is to test as near as possible of the antenna less than one
meter. And afterwards to use the coaxial cable. Depending of the nature and
the length of your cable, you may find very different results! With the
transmitter and the coaxial and the antenna, you test the whole system, not
only your antenna. You can verify this by adding a length of cable and keep
all other parameters identical.
73
F6CNG Olivier
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Le jeu. 16 avr. 2020 ¨¤ 09:06, <s_peter@...> a ¨¦crit :
The Setup is 300W output on 144.300Mhz.The Antenna is 11El.long YAGI on
144 Mhz with Gamma Match and aprox.11m.long RG213 coax (8*¦Ë*0.66).
Measured on the coax in the shack.
The SWR with SWR Meter is 1.06 in the range 143.900Mhz-144.600Mhz.Below
and above this range SWR start to rised quick.
nanoVNA-H v.3.3 blu PCB is calibrated perfect - 2 x RG316 cm cables
SO259 to SMA from eBay, SOLT SO259 verifyed (forget for bad
calibration).On the Screenshot Min SWR and the best Return loss are on
142.000 Mhz. ??? .On 142 Mhz the SWR is incredibly high with the SWR Meter!!
IF I retune the Gamma for min SWR on 144.300Mhz and best Return loss with
only nanoVNA...they are: SWR 1.65 (cant achieve less) and Ret.loss -12 db
->Realy bad, but the Screen shot is prety good -:) ...clear hollow
Is that due to the coax in the path ?? Any sugestions ....
