tuner - feedline - antenna question ?
"
The solution is 4.9 dB.
snip
If anyone wants to challenge the 4.9 dB solution, they can impeach my
reference "Reference Data for Radio Engineers," (various editions). I
can supply other references that have been named in this group too,
but I would suggest with tackling one authority at a time.
73's
Richard Clark, KB7QHC
I have to admit to an error in my analysis of the problem, I made a mistake
with the attenuation of the line.
Re analysing with the correct values gives me the following:
Loss 4.78dB
S11 -5.25dB
Vswr as seen by the source 3.41:1
I think these values are close enough to Richard's answers to make little
difference. I have not got Reference Data for Radio Engineers to hand, but
it may be a graphical solution that could account for the slight
discrepancy. My figures were obtained using Ansoft Designer RF Cad package.
The error crept in because I did the analysis by using 5.35m of coax at 300m
to get the 5.35 wavelengths, and forgot to scale the attenuation value for
the coax.
73
Jeff
|