"David Mills" wrote:
I own a Grundig YB 400 PE short wave radio. I live in New Hampshire in
the Northeast USA. A month a go I was living in a house and was able to
achieve good reception especially with the external antenna that came with
the radio. In particular around 6-7 am Eastern Daylight time..I was able
to
get Radio France and Radio Netherlands. Now I live in an appartment
(building..middle floor of three floors) and the reception is much poorer.
The external antenna that I string up indoors no longer seems to help
much.

What might account for the difference? how best to resolve?

Two possibilities.

1) Shortwave propagation can change from day to day, and month to month.
What frequency band were you listening to? Most shortwave stations simulcast
on several frequencies. On any given day, one frequency may provide better
reception than another.

2) Your apartment building is probably a steel structure. The openings in
the steel lattice may not allow longer wavelengths to pass through.
(Compared to TV and FM, "shortwave" signals actually have a fairly long
wavelength.) How is your AM radio reception in the apartment? AM wavelengths
are even longer than shortwave.

If Number 2 is the culprit (which I suspect it is), you might try dropping a
wire out of a window as an "stealth" antenna. Or listen on the higher
frequency bands.

Art N2AH