Today just for fun I measured my K9AY system from the shack end of the coax
using an MFJ-259B
The loops are fed with RG6 from the antenna to a junction point in the yard
where the RG6 interconnects with RG58 which runs into the shack and terminates
on the Loop controller.(WX0B)
Total feedline lengthapprox 120ft.
Here's what I see:
Minimum SWR 1.2:1 at 2.8 Mhz
Resonance Mode on MFJ
X=0 at 2.0Mhz
R=58 X=26 at 1.83 Mhz SWR 1.6
Max Match Efficiency 99% at 2.8Mhz
MAtch Efficiency 93% at 1.83Mhz
At 1.83 Mhz min SWR (1.5) occurs with Terminating resistor switch in position 1
At 2.8 Mhz min SWR (1.2) occurs with Terminating resistor switch at position 8
So what am I seeing here?....should I be seeing loop resonance closer to 1.8
Mhz? Shouldn't best efficiency match be closer to the 160M band? Does it
matter that the best match is 1 Mhz away from where I want to operate?
The loops appear to be working but becasue the K9AY is only about 50ft from my
tower and 160M Inv L there is some distortion of the pattern but would that
proximity impact on loop measurement that i am seeing.?
Can anyone enlighten me?
73 Frank VO1HP
www.vo1hp.ca
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