[137033] in North American Network Operators' Group
Re: US Warships jamming Lebanon Internet
daemon@ATHENA.MIT.EDU (TR Shaw)
Tue Feb 8 08:47:16 2011
From: TR Shaw <tshaw@oitc.com>
Date: Tue, 8 Feb 2011 08:46:31 -0500
In-Reply-To: <201102081434.38609.denys@visp.net.lb>
To: Denys Fedoryshchenko <denys@visp.net.lb>,
North American Network Operators Group <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
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
>>>>>=20
>>>>> interference. Putting foil (yes i try almost everything) near LNB
>>>>> doesn't affect interference level too.
>>>>=20
>>>> Can you get access to some kind of spectrum analyser kit to see =
what
>>>> the kind of interference is?
>>>>=20
>>>>=20
>>>>=20
>>>> Adrian
>>>=20
>>> 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.
>>>=20
>>> Here is snapshot of carrier spectrum with anomaly:
>>> http//www.nuclearcat.com/PICTURES/interference.jpg
>>=20
>> And does this interference similarly screw up being able to RX data =
from
>> the transponder whilst in Europe?
>>=20
>> (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=20
> today.
>=20
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=92s interference =85 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
=20
