[NLRS] [BC'ers] How to troubleshoot a flaky feedline?

[David Palm]

John,

I did try it with another feedline last night and all was fine, so it's
definitely this one.  I'll probably deploy a spare for the contest while I
figure out what to do with this one.

Thanks for all the good feedback!

73,

David  W9HQ


On Thu, Sep 12, 2019 at 1:21 PM Jon Platt <w0zq at aol.com> wrote:

> The concern with testing with DC voltages via an ohmmeter is that it will
> not necessarily detect if there is water contamination.  If you have
> terminated the end of the coax with a known 50 ohm load and the SWR in the
> shack on 144 MHz is not 1:1 then the feedline probably has water in it (and
> or a critter has chewed on it).
>
> Another trick that I have done in the past is to temporarily steal the
> feedline from a different antenna just to confirm that the 2m antenna is
> indeed ok.  If the SWR is good on the 2nd feedline, then the first feedline
> is bad, again most likely water in it.
>
> Is the suspect feedline 9913 or LMR400 ?
>
> 73, Jon
>
>
> -----Original Message-----
> From: David Palm <thepalmhq at gmail.com>
> Cc: NLRS List <nlrs at mailman.qth.net>; Badger Contesters List <
> badgercontesters at mailman.qth.net>
> Sent: Thu, Sep 12, 2019 12:50 pm
> Subject: Re: [NLRS] [BC'ers] How to troubleshoot a flaky feedline?
>
> Jeff,
>
> I just checked it and a DC continuity test shows 50 ohms.  So that would
> indicate compromised coax, I presume?  Surprising, since the waterproofing
> seemed really tight when I pulled it off, but of course looks could be
> deceiving.  If this is the cause, is it enough just to cut this back a
> couple of feet or so on the tower side and put on a new connector?
>
> Thanks and 73,
>
> David  W9HQ
>
>