Mystery SS signal on 243.820

blaze · #1 (**permalink**) 10-03-2012, 11:53 PM

I've noticed a relatively weak, 40KHz or so wide signal centered around 243.820. It appears to be spread spectrum, and has a bearing roughly to the south from Philadelphia. I'm not sure if it's terrestrial or not. It's been there for at least the last few days (when I first looked).

Anyone else see this?

mancow · #2 (**permalink**) 10-04-2012, 12:43 AM

It's a ss signal from one milsats. It's often referred to as water droplets due the sound when monitoring it in ssb mode. I don't know if it ever stops. It seems to always be there.

blaze · #3 (**permalink**) 10-04-2012, 10:15 PM

Ah, I guess one of the Milstar birds then? Thanks

Rt169Radio · #4 (**permalink**) 10-04-2012, 11:02 PM

What kind of radio are you using to listen to it?

mmckenna · #5 (**permalink**) 10-04-2012, 11:27 PM

Very weak here in Northern California, but likely that's because I'm listening to it on a discone. Interesting noise, I hear the "raindrops" on SSB. Kinda cool.

blaze · #6 (**permalink**) 10-05-2012, 1:20 AM

Quote:

Originally Posted by rt169radio

what kind of radio are you using to listen to it?

r&s pr100

blaze · #7 (**permalink**) 10-05-2012, 1:25 AM

Thanks all.

After doing a bit more checking and taking a more careful bearing, I'm now concluding that this is probably Milstar1-F1, at 39W.

After averaging the signal for a while., It seems to be centered at about, 243.8195, and is about 57KHz wide. Definitely spread spectrum.

Here's a spectrum snapshot showing the (instantaneous) signal: http://www.crypto.com/misc/uhf-sats/2438195.jpg