Hello Auke,

You may very well be hearing IO-26, ITAMSAT.

IO-26 is currently in MBL mode transmitting PSK at 435.790 MHz +/- Doppler, so it's quite a bit lower than the published/launch frequency of 435.822. It has drifted a good bit!

If you share a footprint with my station, you might very well be hearing some MBL telemetry and/or packets coming from IO-26. Keep tuned for more information in the coming weeks :)

73,

Mark N8MH

Well, I got a chance to listen again and there it was again! I took some better notes this time and even got a recording. There didn't seem to be any telemetry frames transmitted, just the steady AFSK carriers. I picked it up about 1/2 way through the pass. I am 90% sure that these signals are coming from IO-26. the LOS occured precisely at 21:05:39UTC Just as IO-26 met my horizon here in DO-33, and the signal was strongest with my antenna pointed in the direction of that satellite. All this is according to my Orbitron display. The only problem is that the frequency is NOT on any list. I worked out the transmitter frequency to be 435.790MHz, where it was 435.7825 when it disappeared. FO-12 was also in view at the time, just as it was the first time I heard this, but it was in the opposite direction from me. LOS happened to occur at about the same time too, hence my less than 100% sure-ness. FO-12 also happens to have it's beacon set to a more believable 435.795, but again, the signal was stronger in the opposite direction from there. One last thing of note about the reception is that I noticed pronounced fading as if the sat was spinning, which seemed to mirror how AO-16 fades both in severity, and rotational frequency. the fades occur about every 10 seconds, for about 1 second, as observed on my 7 element Sinclair Yagi fixed at horizontal pol and fixed elevation of 20 Deg.

Can anyone here offer any help for me to understand these observations? Is it even possible for a satellite to drift this far off-frequency? Can anyone else confirm or dis-prove that these are coming from, or very near IO-26 IO-26's closest downlink frequency is listed as "Downlink 435.8670 MHz AFSK 1200 BPS" as seen here on AMSAT's page: http://www.amsat.org/amsat-new/satellites/satInfo.php?satID=50&retURL=satellites/all_oscars.phphttp://www.amsat.org/amsat-new/satellites/satInfo.php?satID=50&retURL=sa...

Thanks,

73's Auke de Jong VE6PWN

From: "Auke de Jong, VE6PWN" sparkycivic@shaw.ca To: "AMSAT-BB" amsat-bb@amsat.org Sent: Sunday, February 03, 2008 2:28 PM Subject: [amsat-bb] really strange RX

...

I cannot identify what it was that I just heard: at 20:55, i was bringing my dial up to try and hear IO-26, but I was startled when I came accross another signal several hundred KHz below my destination! I stopped to see if it was juse local noise, and found that it was indeed LEO in origin. I picked it up at about 435.801MHz while rotating the beam from the north to my east. As far as I can tell, there is no satellite using a frequency in that range, on the list found on the AMSAT website under "Satellite Frequencies". The signal seemed to be strongest in the direction of IO26/KO25. judging by the rate of doppler-shift it must probably be either one of those satellites. It also faded out just before IO26/KO25 were near my horizon, given the inaccuracy of my PC clock, they might have been exactly at the horizon. It's been a week since I synchronised my clock, it was 4 seconds behind.

The signal sounded exactly like AO-16 MBL mode before they put it in voice mode. I think I even heard a packet or some form of data transmitted once during this pass.

Is it just a typo where IO26 is actually lower in frequency by about 60KHz? Might it somehow have drifted that far down? Or is it another satellite altogether?

Auke de Jong VE6PWN DO33go Edmonton, AB

Mark L. Hammond [N8MH]