[TowerTalk] Force 12 EF-240 SWR shift

[Richard Thorne]

The hairpin is a good place to start.  The weak point is the ring terminals used to attach the coil to the feed point bolts.  I found the hairpin coil laying near the base of my tower.  The winds here finally one.

I used heavier ring terminals during the repair, so far so good.

Rich - N5ZC

Sent from my iPhone

> On Sep 16, 2019, at 11:58 AM, Ed Sawyer <sawyered at earthlink.net> wrote:
> 
> To be clear, just because the SWR gets better lower in frequency (to a 50
> Ohm input) doesn't mean something has lengthened.  It just means that a
> frequency dependent impedance has shifted lower in frequency to give the
> desired match.
> 
> 
> 
> My guess is that the hairpin coil has started to rust and has added
> resistance but is still connected.  You could test that theory a bit by
> putting a carrier on it for 30 seconds and see if the SWR moves.  Or the
> balun could have a similar defect.
> 
> 
> 
> As KK9A said, if the loading wires disconnected or the hairpin disconnected,
> the response would be typically a higher shift rather than lower.
> 
> 
> 
> Ed  N1UR
> 
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