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Satellite Problems

S

spinjector

Hi all,

This morning I was told of a satellite problem we've been having in the mornings at about 8AM EST - repeatedly. There was some confusion because everyone thought it was sunfade, but I was like...umm no kids, that only happens in the EVENINGS. lol

It's happening to both our XDS and Max, so it's not one box - it's either the power supply/DA, LNB, or something else.

So...

A couple questions:

1) Unless I had a stroke and ended up with day & night reversed in my head, sunfade only occurs in the evenings for the northeast USA, yes..? There are no bizarre atmospheric, cosmological, or metaphysical phenomena that could cause it to happen in the morning..? Maybe...moonfade..?? :)

2) A place I used to work at had problems this time of year with an STL due to atmospheric temperature inversion. Can this happen with AMC-8 on a 12-foot dish..? The elevation is only about 9 degrees.

3) It's been getting colder lately. Since it's happening in the morning, I was thinking perhaps the LNB is starting to get dizzy as it warms up. Or maybe it's just getting ready to bust an artery..? Suggestions..?

Thanks.
 
How long does it last?

If it's a really short-term thing, I'm wondering if a vehicle with a REALLY noisy ignition system is driving by on a regular schedule (delivery truck, employee car, etc.)

I have two sites that are next to golf courses and have sat errors when golf carts get too close.
 
LowPayDJ said:
I'd switch out the LNB.
Click to expand...

I second this. Swap out the LNB and see if it fixes the problem. If you don't have a backup LNB, then tsk tsk tsk, you're just asking for trouble.

I have seen one instance where a bird was trying to build a nest in the feed horn and would cause a problem every morning like clockwork. A rubber snake zip tied to the feed arms solved that problem. So you might just want to observe the dish at the time it's been failing and see if you notice anything out of the ordinary. But odds are its a flaky LNB that is getting mad at the temperature change or the morning dew.
 
Just got back from the roof & no bugs in the horn. Although the installer used good waterproof pro sealed F connectors, he didn't wrap it with butyl tape when he was done. It's been raining a lot, so it's possible water got in there. I'll WD-Fortyfy it for now.

Yes I have three different "backups" from my predecessor, two of them look unused, but I think one is an old one from the Starguide days. I'd put a request in the capex for next year for a dual-LNB rig with bandpass filters and some other "beef-up" goodies, including a "Best Buddy" analyzer.

But...of course it goes to heck before then.

I'll sort out these LNBs and if one's the right piece, I'll swap it in. I only have a three hour window each weekday to do it.

Thanks again.
 
Definitely swap out the LNB's. Had a similar situation where it would start out fine and gradually lose Eb/No numbers though the day. The heat from the sun was messing with the LNB which was on it's way out. Replaced the LNB and have 11's all across the board.
 
1. Get an AWACs filter from microwave filter; they are just up the road in Syracuse:

http://www.microwavefilter.com/

It attaches in front of the LNB; filters out military radar; even if this isn't the present problem you will be hit with this sooner or later.

2. Have heard of radar detectors blanking out KU band, though not likely for C-band;

3. If replacing the LNB doesn't cure the problem, see if you can get a spectrum analyzer & plug an LNB into it. Then just swing it around (don't need a dish) and see if you see a strong signal.
Remember LNB have an output in L band, (from 900 up to around 1500 mhz) and the display will be inverted--lower frequencies will be higher on the display.

Cell sites & the like sometimes have rogue transmitters that spew out garbage across the band, but one would expect this to occur a various times, not just mornings. And don't discount TI in C-band. The old terrestrial microwave channels (MCI/ATT) were interspersed between the channels used by the satellite transponders. Some systems are still in use--they may be used for a data dump each morning at the time your sat reception goes south.
 
1) Unless I had a stroke and ended up with day & night reversed in my head, sunfade only occurs in the evenings for the northeast USA, yes..? There are no bizarre atmospheric, cosmological, or metaphysical phenomena that could cause it to happen in the morning..? Maybe...moonfade..?
Click to expand...
Sunfade can happen at any hour on a generic satellite -- but AMC8 is always going to be in the afternoon / evening because of its location in space.

For fun, I looked it up. If you were trying to look at SPAINSAT (which is off the Atlantic coast of Spain, surprisingly enough) from Schenectady, you would have seen sunfade at about 8am every morning last week.
 
ncradioeng said:
Maybe someone warming up their coffee in the nearby microwave? Don't laugh, I've seen it happen.
Click to expand...

Me too. The roof of the radio station was even with the break room on the 2nd floor of the law office next door. Our dish was looking at AMC8 which was just off to the side of the window of the break room in front of the law office building. They fired up the microwave and AMC8 disappeared! Took us forever to figure that one out!
 
TomT said:
1. Get an AWACs filter from microwave filter; they are just up the road in Syracuse:

http://www.microwavefilter.com/

It attaches in front of the LNB; filters out military radar; even if this isn't the present problem you will be hit with this sooner or later.

2. Have heard of radar detectors blanking out KU band, though not likely for C-band;

3. If replacing the LNB doesn't cure the problem, see if you can get a spectrum analyzer & plug an LNB into it. Then just swing it around (don't need a dish) and see if you see a strong signal.
Remember LNB have an output in L band, (from 900 up to around 1500 mhz) and the display will be inverted--lower frequencies will be higher on the display.

Cell sites & the like sometimes have rogue transmitters that spew out garbage across the band, but one would expect this to occur a various times, not just mornings. And don't discount TI in C-band. The old terrestrial microwave channels (MCI/ATT) were interspersed between the channels used by the satellite transponders. Some systems are still in use--they may be used for a data dump each morning at the time your sat reception goes south.
Click to expand...

I'll second this one as I ran into it with a roof-mount C-band sat dish that got overloaded by altitude radar on planes coming in on approach approximately the same direction the dish was looking. The garbage looked like big spikes on the spectrum analyzer. The Microwave Filter unit placed between the LNA and the collector fixed the problem. The problem would come and go when that runway heading was being used.
 
So...no more problems. I'm seeing a bit of chatter around broadcast engineering cirecles about some problems that DG had...? Was there something with Cumulus and WW1 too..?
 
WW1 is DG now, but Cumulus satellite is separate animal.

Cumulus still goes to NYC then to the Vernon Valley uplink cluster for a lot of services--they used to use T1 lines out of Dallas. There are sometimes problems due to storms moving through NYC, but wrong time of year for that, and that would normally be an afternoon one-day problem. Don't know is DG or any of the WW1 services go through NY...
 
Dial Global and Westwood One are still two separate satellite services. I don't think they've even merged the NOCs yet.
 
While we are on the subject, I just received notice from Dial Global that they are changing the transponder from 13 to 23 on their Wegener receivers only at 3 AM on 18 October. The notice also says (and this is underlined) "You must not have any filters inline which block transponder 23 (interference filters, etc.). Please verify with your engineer that no such filtering is in place PRIOR to the upgrade."
 
worst one I ever had to deal with was on a rooftop with a wireless ISP collocated there. This wasn't on amc 8 but whatever bird the local state network is on. the ISP fired up a 3.65 ghz wireless link right above the dish, completely trashed it, receiver showed good rf but 10s of thousands of errors. The worst part about it is this went on for close to a month while we fought with the owner of this ISP that claimed he was not interfering and if he was, why don't we change the frequency we are using (downlink was around 3715 mhz, he was around 3670)

Then this guy sold out, the new people put the same link up again but they were at least cooperative, they turned it off within 20 mins of the first phone call and did something different. Now the company I work for as my day job has purchased that company and eliminated almost everything on that rooftop since we already had a tower site downtown and covering the area fine.

The only other problems we have are wind blowing dishes around and somewhat marginal signal off amc8 due to building owner won't allow anything larger than an 8' dish on the roof. I've found that if I go every 2-3 months and tweak the alignment I can keep it working pretty well with 11-12 eb/no on all networks.
 
Thanks everyone, some great ideas here.

I'm going to start with the LNB, and perhaps the bandpass filter too.

- feedhorn/cavity is free of bugs & water

- didn't consider WiMax.

- there's a large cell tower about 700 feet away, 75 degrees to the left of the dish.

- wondering if someone that works here gets dropped off in the morning by a car with noisy ignition system.

- wondering about air traffic/radar

- unlikely to be radar detector, since the dish points out in to the country over an area with few roads, but the i-90 is about a mile away.

- the one microwave we have in the kitchen has half a dozen rooms and two cinderblock walls between it & the dish
 
The issue I keep hearing is the last second of a network spot from the receiver...like it stutters a bit. It's usually just before a local spot begins, but it's annoying as hell! It happens over and over, especially on Premiere programs, and the network denies that there is any problem and that "no other affiliates have made mention of any issue". I really get tired of hearing this same old excuse...there is a problem...we have it recorded on our loggers and can prove it's happening. Anyone else had the same issue?
 
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