Re: US Warships jamming Lebanon Internet

[TR Shaw <tshaw () oitc com>]

On Feb 8, 2011, at 7:34 AM, Denys Fedoryshchenko wrote:

> On Tuesday 08 February 2011 14:41:29 Adrian Chadd wrote:
> > On Tue, Feb 08, 2011, Denys Fedoryshchenko wrote:
> > > On Tuesday 08 February 2011 14:18:59 Adrian Chadd wrote:
> > > > On Tue, Feb 08, 2011, Denys Fedoryshchenko wrote:
> > > > > I try to install C-Band bandpass filter, no effect at all, so it is
> > > > > in-band
> > > > >
> > > > > interference. Putting foil (yes i try almost everything) near LNB
> > > > > doesn't affect interference level too.
> > > >
> > > > Can you get access to some kind of spectrum analyser kit to see what
> > > > the kind of interference is?
> > > >
> > > >
> > > >
> > > > Adrian
> > >
> > > Yes, on short (few minutes) sweeps it is clean. During long time run,
> > > with 100 Khz resolution, if we run few hours we can catch anomalies on
> > > the carrier. Important note: this snapshot done on spectrum analyser in
> > > Europe, same transponder, and results similar, so it looks like
> > > interference is on transponder. Issue start to affect us at same time
> > > when people in Lebanon got local interference issues.
> > >
> > > Here is snapshot of carrier spectrum with anomaly:
> > > http//www.nuclearcat.com/PICTURES/interference.jpg
> >
> > And does this interference similarly screw up being able to RX data from
> > the transponder whilst in Europe?
> >
> > (eg, if you stick a modem on RX-only in Europe (ie, no uplink) and then
> > just lock onto the signal and decode whatever happens, do you suffer
> > the same problem?)
> Difficult, in Europe EIRP of transponder is too low, to try.
> By the way interference almost disappeared yesterday, and it's much better 
> today.

BTW, here is some comments on the pict from my office mate...

It doesn't show what the sweep span is ... If it's the full transponder, could be narrow band carriers ... The gain 
slope across the pass band looks like CRAP ... He must have a funky LNB ... If this is one carrier, then obviously 
there’s interference … If the spikes are there, it could be radar or it could be some type of burst TDMA junk ... I 
have articles talking about C Band inband interference in Europe somewhere ... Brian