> Since I wrote my original message, I found some additional 59-SP coax
> that was purchased a year ago. It exhibits the same 64-ohm impedance.
> From this, there appears to be a more fundamental problem and not an
> isolated batch problem.
I'd say the effective diameter of the stranded center conductor is a
bit larger than the solid center conductor and they did not change the
density of the dielectric to compensate. That's nothing more than a
basic design error and goes to quality control.
73,
... Joe, W4TV
On 2015-02-15 8:04 PM, charlie carroll wrote:
Jim:
I'm not that far away from thinking the same thing. However, I want to
call the distributor tomorrow and see what they say. They're well known
in the ham community with a pretty good reputation.
Since I wrote my original message, I found some additional 59-SP coax
that was purchased a year ago. It exhibits the same 64-ohm impedance.
From this, there appears to be a more fundamental problem and not an
isolated batch problem.
FWIW, I'm using the VNWA from DG8SAQ and ZPlot from AC6LA. Great tools!
73 charlie, k1xx
On 2/15/2015 7:52 PM, Jim Brown wrote:
I'd say that you have lousy coax from a cheapo manufacturer with poor
quality control, and toss it in the trash.
73, Jim K9YC
On Sun,2/15/2015 3:11 PM, charlie carroll wrote:
I have some rg-59 that I want to use for phasing a couple antennas in a
low-power environment. The 2 cables are marked as:
S.I.W TYPE RG-59/U-SP-95 MADE IN U.S.A
and
S.I.W TYPE RG-59/U-P-95 MADE IN U.S.A
I am looking for the manufacturer's data sheet to understand the
differences and characteristics of the cables. The cable marked "SP"
actually has a stranded center conductor while the other is a solid
center conductor.
The big difference, however, is the impedance of the cable. The "SP"
measures in the 63-65 ohm range with a VNWA, depending on which of
several I measure. The solid-center version measures about 71 ohms on a
single sample. The velocity factor is in the .64 to .66 range on all
cables.
Is there anyone that can point me to some data?
73 charlie, k1xx
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