[TowerTalk] Inner conductor migration in Heliax(TM)

[Steve Maki]

I've handled many hundreds of reels of Heliax over decades, and never
worried much about that warning, which has more to do with creating egg 
shaped cable (from the weight of the upper layers) than to center 
conductor migration. Heliax is very robust. Measure the impedance if 
you'd like, but I'd bet that it's still perfect if it's been kept dry.

-Steve K8LX

On 4/12/2016 2:33 PM, David Aslin G3WGN wrote:
> Hi all, Looking for the TT brains trust to help me out with this
> issue: I have two drums of LDF4-50 and one of LDF5-50 which have been
> stored on their sides for around 10 years.  This disobeys one of the
> prime directives, since Andrew/Commscope say they MUST be stored with
> the drums vertical.  My understanding is that the horizontal storage
> may lead to inner conductor migration. QUESTIONS: How can I determine
> whether migration has occurred; if so to what extent; and what extent
> should cause me to avoid using the cable for the 50m/165ft+ runs to
> my HF towers?
>
> Of course, if there is gross migration, a continuity check from inner
> to outer would reveal a short, but would a TDR or other method reveal
> performance degradation from lesser amounts of migration? 73, David
> G3WGN  M6O