Digital dead?

[pommiecj]

I have a dsr-922 receiver coupled with a solid aluminum metal dish 7.5ft.
For two or three years or more it was losing the digital signal in the evening when it got cold. I had been suspecting a problem at the dish for some time and when the funds came available I started throwing parts outside. It didn't work. I was still losing the digital signals and then regaining them in the morning not long after the sun hit the dish. NOW it is not gaining a digital signal at all no matter that it is 60 degrees.

History: I inherited the dish and an old analog GI machine in 95. I had since gotten the DSR-922. The dish was losing paint in significant patches. I scraped it and spray painted it once but that didn't last very long. About six months ago I hand painted it with flat black Rustoleum enamel but the damage was done in that the aluminum makes a nice reflector to the electronics. The electronics still worked but I was wondering if that was my digital problems.

I got a new co-rotor II+ with LNBs (package) from The Satellite Shop adding KU to my setup. The LNBs are DMS International Model BSC211 Extended C-Band LNB and Eagle Aspen 770LSKu for KU. These replaced the original fixed Chapperal feedhorn with dual Cband LNBs, which were NORSAT no model number, Temp=50K Gain=67DB.

With this setup still not working in the cold, I replaced the cable. The original cable has been through the wars with my wife's dogs and been spliced in a few places.

Now, with pristine cables and a new feedhorn and LNB's I was still getting the digital fade at night and NOW, seemingly permanently. I have been reading about the capacitor issues and was wondering if these symptoms seem indicative of that. I didn't think so at first because of the temperature nature of the problem symptoms. I am now at a point where I think there is a physical (pointing) problem at the dish or the DSR-922 is dying (dead).

I have the cover off the DSR-922 but I don't know what I'm really looking for in the capacitors to see if that is the problem. My dish is in the middle of a dog yard which explains the cable issues (now suspended above their reach) but I was wondering if the dish might be out of alignment due to canine activity or if the dish might be warping in the cold and recovering in the sun. Anything before I throw money at a new DSR-922.

Thanks,
Chris

 

[tdti1]

Sounds like a bad lnb, are both c/ku having issues?

 

[Hermitman]

This sounds like a busted or rusted-through weld on the dish mount. Or maybe a worn or broken attaching bolt. Definitely sound mechanical and not electronic. Maybe you could have someone lightly shake the dish while you look at the dish mount and attaching hardware and see if anything's busted. If you have a button-hook feedhorn mount, maybe a cracked weld on the mounting tube. I'd look at hardware first. Good luck.

 

[turbosat]

If the dogs are big enough or the dish is low enough to the ground, they might have bumped it a few times, knocking it out of alignment. Might be a good idea to try getting the dish tracking the arc as well as possible again, esp since its a smaller dish-it can't afford to lose much signal!
Far as the caps, I haven't heard the 922 having problems with those, I have read about other electronics in past years that suffered from a massive "bad batch" of capacitors that was released on the world, had one computer motherboard die last fall from those. If you look at the boards to see, they will appear like little coffee-cans with the ends raised up, swelled to near popping, or visibly leaking juice out on the circuit board. Time for some PCB repair if you find any that are suspect.
Never heard of a problem with losing channels when cool, usually the other way around.

 

[photoman76]

What digital channels are you watching that aren't working? How is your analog reception? I think you may have an alignment problem and are receiving a marginal digital signal at best.

 

[gpat]

take some detailed pics to post on here.
Have you tried hooking the DSR 922 right at the
dish with only a few ft of leads?
If you locate it to a sat first before you disconnect
all you have to reconnect at the dish for temporary trial is the coax.
Be sure and power down before you dis connect anything.

 

[pommiecj]

Digital mostly dead........

I went out to the dish yesterday following some of your suggestions. I didn't have a whole lot of time so it only got the once over. Standing under the dish so I could see the mount, I grabbed the bottom of the dish to see if there was play anywhere. While everything wiggled a little bit, the only joint I saw with play was the top bearing for the polar axis. The mount I have is much heftier than my neighbors (his dish is now defunct but was a 6' mesh dish probably a lot lighter than mine.)

In any case, I had put the DSR922 back together (I was checking the Caps - no bubbled or dry caps) but then had to go out. When I came back I notice the DC light was lit. Wahoo! That was last night.

This morning, again, no DC light but I hadn't seen the DC light in over a week. The dish is currently parked at G1-3 for guide updates (auto-move). I normally watch the Denver channels on W1-500's or the discovery series on
C3-500's. When digital does not work, I watch Cspan on C3 and C4. I got the KU LNB so I could eventually get SciFi which moved on me (now I hear it's moving back to C ).

Back to the dish, I will try to post some pictures asap. The polar mount is two king pin with grease zirks. I will try to load them up with grease too though if the bearing is worn it will only help temporarily. The bottom pin has an adjustment screw that I could tweak to see if I can readjust to the clarke (rip) belt. If the top pin is worn, my guess is it is tracking just below the clarke belt which is enough to bring in the analogs (CSpans, preachers and peddlers - CPP channels) pretty well.

When I do get the digitals, they pixel at or below around 30 quality; when all is well they park at around 60 in quality.

I'll get some pictures as soon as I find my camera. It's around here somewhere...I know it is!!

BTW, I do have some big dogs but they are not big enough to touch the dish itself. Most are Shelties but we have two Borzoi (Russian Wolfhounds). It's the Borzoi who like to chew on the cables!!:

Chris

 

[truckracer]

You may need to take the receiver and a small tv out to the dish and hook up the motor, servo, and lnb cables. Tune to the digital channels you are having trouble with, then slightly lift up and down on the dish to see if you are getting or losing signal. How is C-span coming in? Is it free of sparklies?

Check all your coax connections for corrosion. If you see any-change the ends.

Be sure to check that your feed horn is tight in the scalar ring and the scalar ring is tight on the buttonhook or feed supports.

If your dish is a button hook type (with the single tube coming from the center) that supports the feed horn, be sure it has not "sagged" down. Measure the distance from three edges of the dish to the edge of the scalar ring and you should get the same measurements.

Do side to side measurements and then one measurement from the scalar to the bottom edge of the dish.

Here is a great link to tuning a dish-http://www.geo-orbit.org/sizepgs/tuningp4.html#anchor801578

Keep us posted.

Do you have a free to air receiver? Those seem to be easier to tune with because the signal meter on the 922's react a little slow to dish adjustments.

 

[zaxxon]

If you havn't already check all of your connections, did they get wet?????

The next thing is new LNB's, they are cheap, yours may be good but at least you will have some spares

good luck

Shalom

 

[pommiecj]

If you havn't already check all of your connections, did they get wet?????

The next thing is new LNB's, they are cheap, yours may be good but at least you will have some spares

good luck

Shalom

I figured the LNBs that I would get bundled with the Co-Rotor II would not be the best on the market and I was concerned about that. But they do seem to work well, when they work.

My connections are all brand new that I installed with the new ribbon cable.
Thanks

 

[pommiecj]

Attached (hopefully I did this right) are pics.
309 - Picture from my deck focus on G1
310 - Picture from my deck focus on W1
311 - Rear view of mount
312 - Side view of mount
313 - Top king pin of polar mount (with play)
314 - Bottom king pin of polar mount
315 - Adjust screw at bottom king pin

Digital down this AM, was up when I got up to take these pics at 5p.....I work at home.

hr

 

[pommiecj]

Still going on

It has been getting worse and I'm beginning to think it is the receiver and NOT the dish but I am not sure.

I just played with the dish....again.....

It is a 90 inch dish with an 18 inch depth.

with F = D**/16(d) = 90**/16(18) = 8100/288 = 28.125 inches

I adjusted the feed horn to this distance from the center of the dish. I am assuming that this measurement is more critical than the placement of the ring. Given the length of the support arms, focal distance causes the scalar ring to come to the 38 position on the feedhorn scale. According to the f/D ratio = 28.125/90 = 31.25 this position gives a narrower field.

Am I calculating this all out right. I moved the feedhorn in the ring to several positions and could only get the DC light to flash but never lock. This was midday at about 80 degrees. When the light was flashing I could only get as high as 54 on the quality reading for G1-3.

Any insight or help would be really appreciated.
Chris

 

[pommiecj]

And the pole is plumb and the analog channels come in like bandits.

One other concern, if I go through to check the VC chip info, the system sometimes says that the VC chip is not found....it seems to work only on VC channels but I recall it used to say that you needed to be on a VC channel, not that the chip could not be found.

Might my VC chip be going and if so could THAT be my issue with the DC channels?

Cchris

 

[sergei]

What kink of reading do you get on different satellites..signal and quality ..analog and digital channels.

 

[pommiecj]

one sat

When I was actively working on the dish I had to stick to one sat, G1. This is because the dish is situated on uneven terrain and getting a ladder to where I can reach the feedhorn is pretty precarious. On G1-3 I was getting anywhere from 1/99 to 42, 44, 46, 47, and as high as 54 but never a lock.

Yesterday afternoon it locked at about 2:30p. Don't know what quality and that was on W1-504 (Denver NBC). The picture was pixelating. I had an appointment so I could not tweak the receiver then.

When I checked it later that evening, about 7p, I tweaked the receiver setting and could only get to the high 40's but the picture was clear. I didn't check the quality again.

About midnight or so we lost the digital lock again.

 

[Radioguy41]

the only joint I saw with play was the top bearing for the polar axis

That's where I would start. Any movement in any of the pivot points will cause alignment problems and it doesn't take much to loose a digital signal. The fact that you did get a green light after wiggling the dish indicates the problem to be mechanical, not electronic in nature.

 

[pommiecj]

Now, therein lies the crux of the issue though.

It didn't come on while I was messing with the dish. I could get a flashing 'D' but never a lock. I had other things to do that day so left the dish and it locked later by itself....and unlocked by itself. It had been at least an hour since I was at the dish and when it's unlocked, no amount of wiggling the dish makes it lock.

I'm wondering now if the dish is warping with the changing temperature. Is this possible with this type of dish? (see the pictures above). As I said it seems to be temperature or at least sun related in that it will not come on until the sun hits the dish.

And, if that's the case, do I have any hope without a new dish?
CJP

 

[Corrado]

I would recheck all cable connectors, especially those outside. I have seen moisture issues change with temperature to cause issues to come and go.

What about insects nesting in the feedhorn? Maybe out in the daylight hours?

How tall are those pine trees visible in pic #3 in front of the dish? Is the line of sight clear? Not that they would change day or night but perhaps affecting a weak signal level.

 

[pommiecj]

I would recheck all cable connectors, especially those outside. I have seen moisture issues change with temperature to cause issues to come and go.

What about insects nesting in the feedhorn? Maybe out in the daylight hours?

How tall are those pine trees visible in pic #3 in front of the dish? Is the line of sight clear? Not that they would change day or night but perhaps affecting a weak signal level.

I was going to replace all my coax connectors mainly because I did not like the ones that came with the new ribbon cable. When I was working at the dish, the connector on the KU LNB came loose and started shorting. My wife thought I was turning the power on and off for the receiver but the shorting was doing it.

If the previous cable was doing temperature based shorting would that have a long term affect on the ability of the receiver to lock on digital? But why only during the day? It's extremely frustrating not having a finite cause in my brain!!

The pine tree are well below arch. There could be TI on the extreme western end of the arch but I think those are below the arch also. All sats have this problem though not just the western ones.

The feedhorn is brand new (4 months) and the cap is secure...no bugs that I can see.

 

[Inno]

Sounds like you've done all the things I'd have done at the dish........is there any way you could get your hands on another receiver to see if you get a lock with it, even temporarily?
I have trouble believing it's the dish itself........can't see it moving that much due to heat/cold.