Topband: Non-resonant receive antennas

[Richard Jaeger]

John,

My experience mirrors your comments.  In the mornings to JA and VK on 160M, the signals are usually best on my end-fire loop arrays, 
but around SR there is often a rapid shift to my inverted L transmitting antenna.  The signals may or may not hold up on the loops.
I guess I should try a low dipole and see what happens.

Dick, K4IQJ ..


On Dec 19, 2014, at 1:43 AM, John Kaufmann wrote:

> A few years ago, I put up a low, non-resonant dipole, about 150 feet long
> and 10 feet high for use as an auxiliary receiving antenna on 160.  My main
> receiving antenna was and still is an array of short verticals.  What I
> found at my W1 location after I installed the dipole is similar to what N5IA
> described at XZ0A.  
> 
> If the band was open before my local sunrise (not always the case!), the
> verticals would always outperform the dipole by a large amount.  However, as
> soon as we hit sunrise, the dipole would suddenly start equaling and then
> outperforming the verticals.  The transition would take place in a matter of
> a few short minutes.  Past sunrise, DX signals would drop into the noise on
> the verticals but would continue to hang in on the dipole.  The dipole would
> sometimes extend the opening for me by 5 to 15 minutes, allowing me to make
> some contacts (mainly JA and VK, if the band was open in those directions)
> that would not have been possible with the vertical array.  Sometimes the DX
> would be virtually inaudible on the verticals but Q5, although not strong,
> on the dipole.
> 
> What is rather interesting, however, is that in the winter seasons of
> 2012-2013 and 2013-2014, this dipole advantage became non-existent.  The
> dipole was never even close to the verticals, either before or after
> sunrise.  It caused me to go outside a number of times to see if the dipole
> had fallen down, but that was never the case.  Evidently the propagation
> mechanisms at work around sunrise have changed from a few years ago, at
> least at my QTH.  So far in the 2014-2015 season, the dipole has still not
> provided any receiving advantage around sunrise.
> 
> I generally don't operate much around local sunset, but I have never seen
> any dipole advantage at sunset.  
> 
> 73, John W1FV
> 
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband