KYOTO News FAX 16969.1 kHz 23:00utc

KA7U

I receive this FAX but it is odd in that it appears to have more than one page of information printed on the page. Is there a special decoder that does 2 page FAX in one transmission?
Ron
KA7U

G8JNJ

Hi Ron,

From memory you won't get clean faxes from the Japanese stations who are using 60rpm with the KiWi decoder, but I believe they transmit English news at 19:00 utc using 120rpm which looks good.

Regards,

Martin - G8JNJ

elitedata

that looks like an two page interlaced fax.
similar to how CRT television operates.

G8JNJ

In old Fax machines the image was placed on a drum which rotated as the image was scanned. Most HF Faxes are scanned with a standard drum speed of 120rpm.

The Japanese pages are scanned at half of this speed 60rpm, possibly because of the structure of the Japanese characters and the layout of the page.

Because the drum speed is twice the actual speed, there is a gap between each scan line, which give the interlaced effect.

It would seem that the KiWi Fax decoder overwrites the first image with the second one due to some sync / end of image signal that is misinterpreted due to the speed mismatch.

Regards,

Martin - G8JNJ

benson

Over at Techzone ( https://goughlui.com/2019/01/13/radio-radiofax-hf-fax-reception-on-kiwisdr-with-kiwifax-py/ ) there is series of blog posts with a lot of current info about HF fax reception in general , active frequencies and slant corrections.

The author indeed shows that Kyodo as last HF fax news agency still transmits faxes at 60 lpm. Also he confirmed that BMF Taiwan has stopped its HF service long time ago and a good candidate for replacement in the Asia/Pacific drop down list would be XSG Shanghai.

He also made some mods to kiwifax.py in order to let it run continuously for DX station capture, suppress the log file and add some drift corrections for non GPS Kiwi nodes.

Regards, Ben

KA7U

Thanks guys for the information. 120 lines versus 60 lines, I get it. I will need to try kiwifax.py .
Ron
KA7U

jks

In v1.318/319 there is support for multiple LPM settings. And the preset for JJC/JSC now selects 60 LPM and was tested (see below). XSG now replaces BMF. And JFC/JFW/JFX has been added per mt-utility.blogspot.com/2010/02/1800-utc-8658-utc-fax-confirmed-jfx.html (I had a successful reception on 16907.5) The frequency for HSW64 was fixed.

A speculative entry was added for GM-11F Ukraine (see: mt-utility.blogspot.com/2009/12/so-who-is-gm-11f.html)
That post is 10 years old. Since 1430Z is 0230 am for me could someone try listening at that time and see if GM-11F is still on the air?



Attachments:
https://forum.kiwisdr.com/uploads/Uploader/3d/c831a3a0669ae6949915e0f653e38b.png

benson

GMF-11F Ukraine wefax no joy.

I used directkiwi (https://github.com/llinkz/directKiwi) to look for possible transmissions today. This very useful Python program created by linkz seems actually not so well known among Kiwi users. By using the audio sockets only it can switch rapidly between Kiwi nodes just by clicking on the node symbol displayed on a world map GUI. Great tool for quickly checking the actual area of propagation of a transmitter as well.

Not surprisingly no trace of these transmissions around 1430 UTC anymore when I checked and the reference is probably too old.

Attachments:
https://forum.kiwisdr.com/uploads/Uploader/8d/fb703cc1f7629375a7a096a9e27aa1.png

G8JNJ

I've also not heard anything from GMF-11F.

It's also not been listed (that I can find) in recent ITU or IARU intruder watch (7090 kHz is in the 40 meter amateur band) bulletins, so it's unlikely, but very occasionally stuff like this does spring up again when they find another Kopek to feed the electricity meter down the back of the sofa.

Regards,

Martin - G8JNJ