Thursday 23 October 2008

Jammers, OTHRs and E10 stuff...

This is the Jammer alone, as recorded today at 0446z on 6840 kHz.

Spectrogram:

Spectrum:

This is an OTHR (Over the Horizon Radar) found today at 0447z on 9130 kHz (another E10 frequency) which is not related (I guess!) with E10...

Pulse:

Spectrogram:

Spectrum:

And this is the Jammer who stops after an PCD2 transmission on 4270 kHz, yesterday at 1900z. (The other noises are just QRM.) The fact that the Jammer stops after the "null" xxx2 E10 transmission may be an indication that the Jammer posses a monitoring station somewhere and checks if he jams an actual message.

Saturday 11 October 2008

Some better images from Honolulu

Yesterday evening I tried again on 11088 kHz and luckily the reception was a bit better! Now you can see a "real" map!

11088.10 USB 1718z TEST TRANSMISSION

Unfortunately the test transmission is a short white chart with a black horizontal line...

11088.10 USB 1734z SIGNIFICANT CLOUD FEATURES

That's better, isn't it? Compare it with the original:


I received two more complete charts until I quit due to excess noise but I think it's unnecessary to upload them now I have at least one good image from them. I'm happy I'm back to HF-FAX DXing, after a long time.

QUESTION: Does anyone of you know if they answer to QSL reports? Any ideas for how to send a proper QSL report? So far I got response only from amateurs, so far no response to a letter sent to Northwood and an e-mail sent to Hamburg...

Thursday 9 October 2008

And yes... Honolulu!

Propagationally speaking, Honolulu is more difficult than Wellington, New Zealand, even if it is closer (13700 km instead of 17400 km).

Yesterday, I had some luck with Honolulu!!! The frequency was 11088.1 kHz USB, starting at ~1723z till ~1834z.

Here is a comparison of my received images to the ones actually sent. Mine are the top (and noisy) ones:

1724z SIGNIFICANT CLOUD FEATURES


1735z CYCLONE DANGER AREA



1755z STREAMLINE ANALYSIS

Despite the noise, I think there is some resemblance with the original images. These are provided by NOAA and I was lucky to find the originals today since they keep only the latest images! I've got Honolulu! What do you think?

More on E10 jamming

This morning I decided to check 6840 and 7690 for any jamming over EZI. Interestingly, the jammer started at 6840 kHz and then decided to jam 7690 kHz, even if there was an EZI2 message.

The recording is from 0627z this morning, on 6840 and 7690 kHz, USB mode.
The first 1min 58 sec is on 6840 kHz. You can hear the YL calling EZI2 just before 0630z. Then at 1min 33sec the jammer stops. I'm still on 6840 kHz. At 1min 53sec you can hear some code and then at ~1min 59sec I switched to 7690 kHz. Hey! The jammer is here now! At 3m 18sec or ~0630z EZI2 starts normally. I switched back to 6840 at 4min 24sec but no jammer there, just CW. Then I switched back to 7690 kHz, till the end of EZI2 transmission, The jammer stopped just few seconds before the YL.