Monday, 4 August 2008

Athens HF-FAX service improves its transmission quality

The local HF-FAX service, Athens, suffered from bad transmission output (probably too much audio level in an SSB transmitter). See my older post. Nowadays all seems to work fine; the image quality is superb:

8105 kHz USB, 03/08/2008, 1007z

8105 kHz USB, 03/08/2008, 1019z

Both images logged yesterday morning on 8105 kHz USB mode with a +20dB signal. Athens also transmits on 4481 kHz (had an S9 signal). Usually the lowest frequency is better received at my QTH, but if ionosphere permits (relative) local propagation on higher frequencies, the 8 MHz transmission is better, with less multipath distortion (fuzziness of the lines).


Anonymous said...

Thanks for the information. I didn't even realize that there was HF weather FAX transmissions. I just copied one very close to here. It's a good way to check on propagation conditions.

I spent a few hours on your beautiful island years ago when I was stationed a Hellenikon and many of my students were assigned to the base on Crete that I can't get the spelling of right, at the moment.

Simi Valley, CA, USA

Manolis said...

Hello westli,

Nice to see you! Yes, FAX stations are very interesting (for example Kyodo News) and useful (for weather reports).

FAX transmissions are affected by multipath propagation ("spreading" of the lines) and yes, they're nice guides for propagation, for example Australia/N.Zealand. And in my case, Athens is one crude indicator of the MUF, since the 8 MHz transmission is not always as strong as the 4 MHz transmission.