Those fractional dB numbers, which are for 100 ft of cable, add up when
the coax gets long. The run to my SteppIR is 350 ft, and I use it on 6M.
That's why I scrounged the used 7/8-in hard line to feed it.
I'm using Belden 8213 on my high (135 ft) 80/40 dipoles. The closer
match of 75 ohm cable to those antennas (approximately 85 ohms feedpoint
Z) through 160 ft of coax saves me fractional dB, and more at the band
edges.
The important point here is that every engineering problem is DIFFERENT.
One size does not fit all. I'm using Commscope 3227 (#14 solid copper
center, shield like LMR400) for the 200 ft lines to my 160M slopers.
73, Jim K9YC
On Wed,2/18/2015 10:47 PM, Roger (K8RI) on TT wrote:
How often can the difference between the following even be detected?
It is after all, only o.5 db. 1 db can just barely be detected under
ideal conditions. If this is the standard 9913, I either gave away,
or threw out nearly 1500 feet of nearly new 9913.
LMR400 0.7 dB
RG213 1.2 dB
9913 0.7 dB
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