Wednesday, 20 June 2007

This is how E25 sounds on 6140 kHz, with NO RAI present!

Great luck today!

I got E25 on 6140 kHz this morning (0817z) calling "955 21" in USB mode. The frequency was clear from RAI thus giving me a chance for a signal measurement! So E25 was S7 max on 6140.

You can listen the transmission here.

Less than an hour later, at 0901z, E25 sent a message to "570". Signal was in USB, RAI-free but with some QRN. Signal was S5-S7.

Here is the message:

2313 3178 0588 1355 7091 0895 9354 8088 8008 5284
9852 1744 5259

This is the full transmission! I deliberately detune my radio to check if it was an AM transmission or LSB-suppressed. Also you can hear the switchover from the guy calling "570" to the guy sending the message.

And yes, more action followed!

At 0916z a stronger carrier appeared, and it wasn't RAI! Music followed, in AM mode, peaking S9+ but most of the times it fluctuated around S8. So this must be another transmitter on the same frequency!

Music continued and at 0930z an OM started calling "405 425" and then "405" only, under the music! The message was:

8920 8053 9788 0251 0753 8751 1008 0448 4098 8715
5405 7539

Listen what actually happened! Again, an other guy announced the message.

The music session ended at 1021z.

I'm almost sure these was two different transmissions on the same frequency. Today's observations are of great importance, if you also take account the occurrence of another test transmission from at least 0710z (as reported by Mike on E2k Group) until 0816z with a S9+ to S9++ here and S9 at 0710z in UK at 0710z.

I was extremely lucky today; being in my shack to note down signal strengths in a RAI-free frequency :-) instead of the usual record-and-check-later procedure which means no signal strength measurements!

Monday, 11 June 2007

Two simultaneous E25 transmissions on 9450 kHz

E25 is active on 6140 kHz -- messages are sent in almost daily basis, but I have to recover them from unattended recordings with a lot of RAI QRM. Anyway, one exciting thing happened today on 9450 kHz:

At 1144z there was an OM calling "788 63 62 61 59 52 785 50 46 45" in USB mode and in relatively low signal strength, an AM carrier appeared (very strong) and another OM started calling "788 52 59 61 62 63 785 45 46 50 60"!

This is a recording from the weak signal just before the AM carrier appeared (USB mode).

And this is a recording featuring both guys (USB mode, a couple of minutes later).

The always-exciting world of E25 continues to surprise me...

Sunday, 3 June 2007

E25 uses Windows

Listen the Windows OS startup sound and some background chat when the E25 transmission on 9450 kHz, AM mode, began at 0957z. Now (1015z) they're still playing "Inte Omri". Recording made in USB mode to avoid splatter from Radio China International on 9440 kHz (my AM filters are not so tight...)

Friday, 1 June 2007

New edition of rfax is available

A new edition of the rfax.pdf HF-Fax list by NOAA is available. I haven't thoroughly compared it with the previous one, but seems to have the latest info regarding JMH. On the other hand, no further info about Rome Meteo, which I'm not sure if it is still on air.

Sunday, 27 May 2007

E25: New frequency found!

Yesterday Mr. DXer alerted Enigma2000 for the existence of a second E25 frequency, namely 6140 kHz. A message to 880 sent at ~0700z.

And yes, it's true! E25 appeared at 0700z calling "880", under RAI Radio. They sent the same message as yesterday in English:

4621 4401 2895 8976 9541 1828 2294 2785 0932 4621

A bit different format, this time first and last groups are the same, and I wonder if the group containing the group count and serial is the second one: 4401: 44 → 44 is the serial? 01 → 10 is the group count? For the moment, it seems to be. More messages needed to clarify the situation.

ID 880 is entirely new to me; and in contrast to other 8xx IDs, the message was in English.

Listen to E25 under RAI, message to 880.

The moment I'm writing this, 0801z, E25 calls "200 8" (a control message to Agent 200)! This ID heard only once back in 12/3/2005 at 1250z! Wow! A whole new world under RAI....

Listen to E25 calling "200 8".

Saturday, 19 May 2007

E25 live & playback transmission

At 1007z today, carrier and a 1000 Hz tone appeared, and an OM started calling "315", a rather rare ID. Then a 13-group message followed in AM mode:

g13
3284 6390 4131 2962 0255 9232 9142 4133 8427 7405
2188 6390 7695

After the "End of message, end of transmission", the OM started calling again "315" at 1019z! The song "Arouh Le Min" heard at 1026z and then again the OM called "315" and the whole message delivery procedure was repeated. Here is the whole transmission. Signal was lower than usual.

After a little research, I proved that the operators decided to playback the message session. They did it again for Agent 315 in the past. I created a 2-channel audio file, putting in the Left channel the initial message and in the Right channel what I believed to be a playback. If the resulting stereo file sounded without echoes (=timing differences), the second repeat was indeed a playback. Only propagation differences should be present. Here is a short sample of the resulting stereo file. Do you notice any timing differences? I don't.

Second transmission:

E25 appeared again at 1126z, with the song "Arouh Le Min", calling "555" and sending the 13-group message:

g12
9150 9121 3911 4428 3360 2388 1821 8231 9908 8180
7623 3911

(listen!)

A typical message which follows the guidelines of my article in Enigma2000 Newsletter #39. The transmission was in AM mode, with a stronger signal.

Friday, 18 May 2007

E25: AM or not AM?

A brief "control" transmission from my favorite Enigma, E25, occurred today at 1143z. An OM started calling "785 58 788 45 46 50 52". The transmission was in AM mode.

Next, I'll show you the spectrograms from these transmissions: While recording, I switched to USB and detuned the radio for 1-2 kHz to see if both sidebands are present. Today we had...

The 1000 Hz horizontal line is the carrier, both sidebands present. (Audio)

Yesterday it was another story... LSB-suppressed, a couple of problems during startup, and a brief musical segment just before they QRT. The "control" message was "788 45 46 50 52 58 " also sent at 1143z.

The 2000 Hz line (and a 1000 Hz bit during re-tuning) is the carrier, only USB present. (Audio)

I hope this visual/audio representation was useful. I wonder when E25 operators will settle in a fixed mode and a fixed schedule...