Topband: Soliciting suggestions on our receive antennas for 5X8C

[Bert Barry]

Dave,

Your difficulty may be the result of expecting vertical polarization to 
work well an low geomagnetic latitudes.  In his " Big Gun's Guide to Low 
Band Propagation", the late Bob Brown, NM7M, described how the resonance 
effect of the proximity of 1.8 MHz to the gyrofrequencies of electrons 
in the ionosphere can increase absorbtion of top band signals at low 
geomagnetic latitudes.  Conversely, at high magnetic latitudes the roles 
are reversed.  The gigantic 160m horizontal yagi of OH8X was apparently 
a huge disappointment, probably for this reason.

You might want to try inverted L's or T's, as high as possible.

Bert,  VE3QAA

On 10/02/2013 4:05 AM, Dave wrote:
> Hi All,
>
> My team is currently on DXpedition to Uganda 5X8C
>
> We have erected receive antennas here in 5X with very poor success. W e have used the same antennas at other places with great success.  Please read below and if you can offer some constructive suggestions please reply to me and copy reflector.  Davek4sv at yahoo.com
>
>
> We are experiencing some weird problems with our receive antennas.  We have a beverage about 540 feet long, terminated properly about 5 to 6 feet over the ground.  I have built plenty of these at my house, they all work.  This one here does not.  It hears noise but no signals.  Once In a while you can hears signals.
>
> So put you're receive antenna hat on.  We suspect the ground is the problem.  We are located on the shore of Victoria Lake at a resort.  The soil appears to be sandy but with fresh water lake nearby. 200 feet.  The beverage is in the clear away from large metal objects.
>
> With a 510 ohm termination we measure about 235 ohms when looking across the termination resistor.  Using resistor theory essentially we have two resistances in parallel.  The wire , termination transformer, ground rods and ground are about 500 ohms.  Having not measured this at home I'm not sure if this is too low or too high of resistance.
>
> We erected a Flag 29x14 feet mounted just above the ground.  This is purported to be ground independent.  Our tests last night indicate this antenna is not hearing very well either.
>
> We are soliciting suggestions.  We only have a small amount of wire and other antenna stuff, no Home Depot or Radio Shack around.  Perhaps we can build a ground independent antenna that does not care what it sits on.
>
> We have or can source some wooden poles to make wire radiators.
>
> The 5X8C team thanks you in I
>
>
>
> Thank You in Advance,
>
> Dave Anderson, 5X/K4SV
>
> Sent from my iPad in Uganda
> _________________
> Topband Reflector