I have had traces on the ends of hardline that looked like calcium or maybe
salt deposits. Slightly off-color, almost invisible, They conduct from
center to shield. It is difficult to scrape them off. They usually will
register as a resistance on an ohm meter. Sometimes resistance is lower at
one end, indicating the path at that end. Might want to cut an inch off to
get rid of the end and start over.
Try an ohm meter on the hardline. Any resistance, even in the megohm range
is bad.
Chuck W5PR
On Sun, Oct 15, 2017 at 5:59 PM, <kr2q@optimum.net> wrote:
> I was wondering why I did not get any follow up emails to my original. I
> had made an additional post,
> but in error, I only hit reply and it never went back to the group. So
> trying again.
>
> As a reminder, I have 160' run of 7 eights Heliax what worked fine all
> last summer, fall, and winter. Last time it
> saw power was at the end of January.
>
> About 6 weeks ago, I turned on radio and shot out 100 watts and found an
> SWR of 3:1. I did all the normal checks and the
> problem is actually the coax. Putting a dummy load at the far end still
> showed 3:1 and when I put the dummy at the jumper
> feeding the near end (in other words, bypassing the coax), the SWR was
> 1:1. I opened up both ends and found no water and
> no moisture. Sorta like the X-files. It's not the antenna, so you don't
> need to know what it is.
>
> Here is my additional post from a month ago.
> de Doug KR2Q
>
> I have multiple responses already. Here is some more information.
>
> I do not have real connectors for 7/8 Heliax. I took a chassis mount
> SO239 and soldered it to the cut end
> (each end) of the heliax. I used copper wire to make the connections.
>
> Therefore, there is no water in the connector because there isn't a
> "connector." I did have them taped up with Scotch 88.
>
> When I opened them up, there was no moisture inside and certainly no
> liquid water.
>
> Both ends were, and are, well above ground (measured in feet), so no, they
> were never sitting in water.
> Each end has a "loop" of RG8 connected to it, so there even if rain were
> to "run down the coax," it would
> or should just drip off the bottom of the RG8 loop...no way to travel up
> hill back to the "connector" with the Heliax.
>
> The connections (wire soldered to the outer conductor and to the center
> conductor) are no longer "shiny" but are electrically sound (DC).
>
> As I said, this has been in use since last Summer, through the fall and
> winter (through Jan 21, 2017) without issue.
>
> As for water ingress, where would that occur? Would the dielectric "suck
> up water?"
>
> I really can't see where the water would come from and if any, "not
> enough" to make that
> much of a difference in the course of ~6 months?
>
> I don't have a TDR and locals who have responded have various MFJ
> analyzers, but not one
> that has TDR capability. But seems that is a good route to follow. Would
> be great to identify
> an impedance bump somewhere.
>
> Yes, at some point, I can cut off the ends and see what happens, but how
> much should I hack off?
>
> Any other thoughts?
>
> Thanks
> de Doug KR2Q
>
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