Do BUDs die?

[trinidex]

I've got a 14ft prime focus mesh dish with a Chaparl dual (fixed) polarity feedhorn and 2 LNBs - there is also a positioner, but I've long forgotten who made that!

I use it for G5 a lot, CNN, TNT and TBS mostly.

Over the past few months the PQ has been degrading, lots of sparkles. I've used the positioner to nudge the dish but nothing seems to improve the PQ, only make it worse.

Recently I changed both LNBs, but that made no difference.

Just this morning, in desperation, I took a TV, receiver et al down to the dish and tried peaking it but to no avail. - I used a new run of RG6 from the LNBs.

I tried adjusting the skew of the feedhorn, although that has been fixed since installation, I manhandled the dish, but nothing helped.

In a final move of madness, I released the bolts that hold the dish on its pole, there was a terryifying 'creak' as the dish moved, almost out of relief!

Anyway, now I have nothing, well not nothing, outside, if I push the dish right and hold it, a picture comes in, but it is still bad, and then when I tighten and let go, picture is gone.

So back to my question, do dishes (BUDs in particular) fail?

Or am I looking in completely the wrong place.

P.S. The wife is gonna be sooo mad tonight!!!

 

[tdti1]

You should always mark the pole before making a polar axis adjustment, mesh dishes lose there shape over the years, but it would be noticed more on ku-band, what lnb did you put on? the Norsat 8115 is a good one, the dish and feed may be off, this can cause issues, get your digitals going strong thats the important thing these days.

If you have a lnb offset in the receiver play with that on analog, also fine tune the freq and it should eliminate most if not all the sparkles.

You can open the bolts and move the dish on the pole one way and the other and bump it east west slightly once you get the pic clear enough try locking it up with out moving, then you can go inside and play, it really sounds like a receive site issue due to poor alignment or lnb settings, the tuner in your receiver may not be that great also, don't feel bad, even professional receive sites have some sparkles some times, it's kind of funny, you can see it some times when the original feed was analog and you are watching it on digital cable or pizza and notice sparkles haha, I see it on dvb feeds to at times and a few time on DC channels.

 

[trinidex]

Thank you for your thoughts tdti! - and encouragment - need that right now!

The LNBs are DMS International BSC211 Extended C-Band LNBs
LO: 5150 MHz
In: 3.4-4.2 GHz
Out: 950-1750 MHz
Noise: 13K
Gain: 65dB

Regarding your comment about the digitals, recently I've not been able to get those at all!

Something just occured to me...is it possible to mount an LNB upside down?
The original LNBs had 8 screw holes, the new ones only have 4 (on the left/right edges) looking at one in my hand I notice the 'mouth' isn't centered. Presuembly, if it were upside down, it would not receive all of the signal?

Thank you

 

[tdti1]

For c-band no anyway is good, for ku-band you will need to make sure you place it on good as it can go 4 ways but 2 will work.

If the dish is not damaged or warped then you should be fine, centring the feed and proper placement is very important, the reflector alingment is also very important, your lnb is not one I personally would recommend but it should work fine as long as the dish is set correctly.

What receivers are you using?.

 

[Corrado]

It's possible the 14' dish may have settled a bit into the ground allowing it to be out of alignment. Does it still track the arc? Is the pipe still plumb? Is the mesh damaged? Anything change in the line of sight over the years? Trees, buildings, etc.

While next to the dish with the small TV, try to push or pull a bit to see if the signal improves

When loosening and relocating post bolts the dish will probably settle back into depressions made in the pipe. Unless a strong windstorm twisted it on the post I would leave those alone.

 

[trinidex]

As far as I can tell the dish isn't warped - the mesh has seen better days - a couple (no more) of the panels don't fit into the slots exactly like they did when it was new. This affects only one side of a panel, and instead of being in a slot, it is laying on top of the slot.

We've been very lucky with obstructions, we don't have any!

I'm using a HTS Tracker 70 Series (with timers!!!) I also have a DSR920 which I use more on X4

The dish is mounted on a concrete block (purpose made), there are steel rods, to which there has been some corrosion.

The more I read comments & suggestions it may be exactly that - the dish may have settled/shifted sufficiently to cause this problem.

Whats bugging me is, seemingly no matter which way I twist or pull the picture never gets better only worse.

Back outside we go

 

[tdti1]

Remember to bump east and west every twist, as long as you can get it back to where it was your should be ok for now, I would recommend a tech with spectrum analyser for alingment, since you already moved it on the post you will need to try to set it back to where it was, there should be indents in the post already and I hope it's not hard for you to find them.

 

[trinidex]

On the road to recovery...

I went back outside armed with everything remotley satellite dish related and set to work.

I inspected thedish more closley this time, and spotted a bolt that had corroded and was hanging out of the hole it was supposed to be fastened through - this hole, it turns out, helps connect the back of the dish to the mounting plate that is connected to the main mount!

I popped in a new bolt & nut and tightened it up. Then, I connected up the TV & rcvr, and BOOM, I had TV!!!

It's not perfect, but its better than it has been, mainly white sparkles, can't seem to do anything to get rid of them, don't want to do too much incase I bodge it up again.

Talking of spectrum analysers - I have a 'Canary' which is labelled a 'Spectrum Analyzzzer' so named because it emits a (sometimes annoying) chirp/whistle/scream which gets louder and higher pitched the better the signal. This works well for my Ku DCII stuff, but I can't get it to do anything for VC2+ Analogue - strange or normal?

 

[turbosat]

I'd still check that pole for plumb, put your level on 4 places around the pipe to make sure it hasn't shifted. We are in such a record drought here, the ground is so dry that is the first thing
I think of now, when I have problems. Had to re=plant a 12' back in the early summer just because of the cracking shifting ground.

 

[trinidex]

Forgive my ignorance, I'd like to check the pole, and I'd also like to check the LNB arm.

How can I make sure the ploe is straight n'true? Can I use a spirit level vertically on the pole?

Also, how can I check the LNB arm is pointing dead centre?

Since its been back up and running, I've noticed CNN (Tr 5) is pretty damn good, very few sparkles, but on HBO and TNT they are more pronounced, white only though

Thanks you guys!

 

[sksatellite]

Forgive my ignorance, I'd like to check the pole, and I'd also like to check the LNB arm.

How can I make sure the ploe is straight n'true? Can I use a spirit level vertically on the pole?

Also, how can I check the LNB arm is pointing dead centre?

Since its been back up and running, I've noticed CNN (Tr 5) is pretty damn good, very few sparkles, but on HBO and TNT they are more pronounced, white only though

Thanks you guys!

Try adjust the focal distant from the feedhorn to center of dish. or rotate the whole feed a bit depending where you at to the left or right.

 

[turbosat]

take your 2' level and hold it up against the pole (vertically of course) check the bubble. then just do it on 4 places around the pole. A tiny bit off won't prob hurt much, half a bubble might cause trouble with ku and tracking the arc. Hopefully it won't be the pole, most likely you just got some sagging and lost the arc.

 

[tdti1]

Take a look at the feed make sure it's set up right, once you have it set skew bump and offset the lnb to the best reception, if you still have sparkles go out and push the dish slightly up and then down see if anyway gets better.

Read this site for great info Footprints by Dish Size - Adjusting the Polar Mount for Prime Focus Antenna - C/Ku-Band Satellite Systems - Tuning, Tracking, Azimuth, Elevation, Declination Angles, F/D Ratio, Focal Distance, Inclinometer, LNB/Feedhorn Assembly, Actuator Assembly, C