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
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.
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
>>>> 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
>>>>
>>>> --Michael
>>>
>>> +1 for Microwave Filter. They've helped me out in a couples jams
>>> before. They're very responsive and the products are good, too.
>>
>> I think people in San Diego and near Norfolk, VA have the same problems.
>>
>> 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 interference. Putting foil (yes i try almost everything) near
> LNB doesn't affect interference level too.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.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?
Yes, for sure i did. I am running C-Band at this location not first
years, and know very well how industrial sources looks on spectrum analyser,
and it is easy to triangulate them (i can go up to 9Ghz).
Vessel radars also relatively easy to catch, especially with sound
demodulation.
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?)
Adrian
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
It is PLL LNB, one carrier, we are using full transponder 36 Mhz. There is
almost no other users on this satellite (inclined more than 1.5 degree), and
other carriers center frequency 100Mhz away.
Been there in 2007- different disruptor, though . See:
http://en.wikipedia.org/wiki/Yes_(Israel)#Technical_problems_.28autumn_2007.29
http://www.haaretz.com/print-edition/business/a-nation-steps-up-to-rescue-yes-1.230782
-Hank
Since no one else will, "I blame solar flares!"
Jack
I am monitoring solar activity, getting info from NOAA. No correlation.
denys@visp.net.lb wrote:
Your suspicion may be accurate and accidental. I rented a car in San Diego the other day -- there was a sign warning that the key fob might not work within 5 miles of the port -- San Diego has a major Navy base -- because of interference from shipboard electronics.
--Steve Bellovin, http://www.cs.columbia.edu/~smb
Yes, for sure.
Satellite operator doesn't provide much help, but uplink proposed for us some plan to solve all this issues.
Already we implement temporary solution, and things at least stable now, plus it seems interference is lower somehow few last days.
It is PLL LNB, one carrier, we are using full transponder 36 Mhz.
There is
almost no other users on this satellite (inclined more than 1.5
degree), and
other carriers center frequency 100Mhz away.Since no one else will, "I blame solar flares!"
Jack
I am monitoring solar activity, getting info from NOAA. No correlation.
Have you been able to get any assistance from the uplink/teleport noc
or the satellite operator?Yes, for sure.
Satellite operator doesn't provide much help, but uplink proposed for us some plan to solve all this issues.
Already we implement temporary solution, and things at least stable now, plus it seems interference is lower somehow few last days.
Here is a dumb idea that I have actually seen cause problems :
Is it possible that the declination of the satellite from your location is the same as the Sun right now ? That will cause up to several hours of interruption every mid-day. The clue is that the shadow of the receiver box is in the center of the dish (for prime focus mounts).
You might be surprised how many times this has caught people, so I thought I would mention it.
Regards
Marshall
Your suspicion may be accurate and accidental. I rented a car in San
Diego the other day -- there was a sign warning that the key fob might
not work within 5 miles of the port -- San Diego has a major Navy base
-- because of interference from shipboard electronics.
same time, my phone's gps claimed accuracy to 700m in the 10 miles from
san diego airport. that is not a lot of good for nav. luckily i used
to hang down there in the late '70s and early '80s so kinda knew my way
around.
randy
That sounds like it didn't have a GPS fix at all, and was instead using cell
site proximity location. (I didn't check my phone's GPS; my Garmin unit had
no trouble.)
--Steve Bellovin, http://www.cs.columbia.edu/~smb
Usually we are preparing for solar interference before 1-2 month, and we know exactly when it will stop 
Plus it is happening max 10-15 minutes per day, and i had complete outage for few days.