Yas thanks for that - I did a little unscientific study both in Singapore and Tianjin/Tanggu east China, as where to plonk the probe to best affects.
What was interesting was a new Block of Apartments was slowly rising in height over a year or more period and I could take rough base link groundwave and skywave measurements for this obstructed (dump to ground) path, and for paths that were more open.
The attached was the results. The final location "A" up and outboard and up from the corner of the building was an attempt to reduce the blocking, get some "air" and allow the non probe coax side to get a little length, before it was bonded to the main building frame. This appeared to work ok as we managed to receive Eu stations on 137 and even SM6BHZ on 500kHz from there in Eastern China. Following your tests with great interest
> Date: Wed, 17 Aug 2011 21:32:01 +0900
> From:
[email protected]> To:
[email protected]> Subject: Re:Re: Re:Re: LF: DCF39 in JA
>
> Hi Roelof,
>
> Yes, you are right. Thanks to the advice from Laurence thru Scott,
> I finally set up the Ant No.1 to that location.
>
> Also, here is the comparison between Ant. No.2 and another mini-whip
> extended from my room. Hope the sketch is self-explanatory:
> http://icas.to/idc-136x2-kit/splb/antenna-comp.htm
>
> The another mini-whip was extended 0.5m, 1m, 2m, and 3m off the
> window respectively. The traces were of VOR on 153kHz.
>
> 73,
>
>
> Yas - JA8SCD/1
> Tokyo
>
> --- Roelof Bakker wrote:
> > Hello Yas,
> >
> > I have looked at your nice drawings.
> > Mini-whip no 1 is much more in the clear than no 2.
> >
> > No 2 is close to the tall building next doors.
> > It is not only height that makes the difference, but also the screening from nearby buildings, trees etc.
> >
> > So, it might be interesting to relocate no 2 close to no 1!
> >
> > If at all possible, you could even try to mount it away from the building on a horizontal mast.
> >
> > 73,
> > Roelof Bakker, pa0rdt
> >
> >
>
