[137027] in North American Network Operators' Group
Re: US Warships jamming Lebanon Internet
daemon@ATHENA.MIT.EDU (TR Shaw)
Tue Feb 8 07:35:48 2011
From: TR Shaw <tshaw@oitc.com>
In-Reply-To: <201102081359.39100.denys@visp.net.lb>
Date: Tue, 8 Feb 2011 07:34:58 -0500
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 6:59 AM, Denys Fedoryshchenko wrote:
> On Tuesday 08 February 2011 01:42:42 George Herbert wrote:
>> On Mon, Feb 7, 2011 at 2:23 PM, Ryan Wilkins <ryan@deadfrog.net> =
wrote:
>>> On Feb 7, 2011, at 4:06 PM, Michael Painter wrote:
>>>> Hi Denys
>>>> I doubt it's intentional jamming since I've had the same problem.
>>>> Aegis radar is very high power in full radiate mode and as such =
creates
>>>> problems for Low Noise Amplifiers listening at 3.4-4.2 GHz. Someone
>>>> needs to talk to Microwave Filter Company.
>>>> http://www.microwavefilter.com/c-band_radar_elimination.htm
>>>>=20
>>>> --Michael
>>>=20
>>> +1 for Microwave Filter. They've helped me out in a couples jams =
before.
>>> They're very responsive and the products are good, too.
>>=20
>> I think people in San Diego and near Norfolk, VA have the same =
problems.
>>=20
>> The C-band frequencies are 2x those of the S-band (4-8 GHz for C, 2-4
>> GHz for S); if the SPY-1 / SPY-1D radar is frequency hopping it may
>> well step on someone's C-band links at twice the radar's basic
>> frequency. Just need a filter to remove actual S-band frequencies
>> from C-band feeds.
> 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=20
> affect interference level too.
>=20
It can come in from other places as well. Inductance via =
unfiltered/poorly-filtered power, poor I/F cabling as well as via other =
sources.=20
Have you tried using a spectrum analyzer to characterize the signal in =
the ether and compare it to what you are seeing in your systems?
Tom
