Yet again! No horizontal on ses 1 at 101

[tiredold]

I replaced the LNB with a Titanium dual (incredible), new coax, realigned feedhorn. Everything worked great!! Signal 91, quality 84 (on horizontals) 40 on verticals. That is until I noticed today. Two recievers. One shows nothing on horizantals, the other shows 91, but both show 0 on quality. Everything is good on satellites on either side. Rescanned, cursed, everything I can think of. No joy. I would appreciate any help.
Jeff

 

[arlo]

Shoot me a satellite that you get with different signal levels on H & V transponders.
Give me the frequencies and polarities. Where abouts do you live?
Can you switch to display decibels? If not, no biggie

 

[Conway]

I do know if you are upgrading from a C1PLL the 0 skew arrow is opposite.

 

[tiredold]

I am in Toronto Ontario Canada. Upgrading from a BCE dual output? Before all transponders came in at 91% strength. Now some of them are fluctuating from 40% to 90%. But what has me stumped is 91% strength and 0% quality. 5G? Every other satellite works as it should.

 

[mikekohl]

I am in Toronto Ontario Canada. Upgrading from a BCE dual output? Before all transponders came in at 91% strength. Now some of them are fluctuating from 40% to 90%. But what has me stumped is 91% strength and 0% quality. 5G? Every other satellite works as it should.

Your 91% strength reading confirms that you are operating the system, but not really much more than that. If you have a similar reading on the other polarity, but have a fair to good Quality reading, that is where you should be adjusting and monitoring. Quality reading often differs between H and V, so peak one of them for highest reading and then go to the opposite polarity on a transponder assigned to it.
Balance back and forth until both have something more. Fine tune dish up and down as well as left and right to get highest reading on your strongest side. Once there, go back to optimizing each polarity separately until they are fairly balanced in level. Good luck!

Mike

 

[tiredold]

How would I fine tune the polarity? Change the skew of the LNBF? I tweaked the east-west quite well. The sats on either side work really well. Tonight the verticals are pixelating and breaking up as well. Same problem I had before changing everything.

 

[arlo]

Better hurry. Warm weather is adios. I live 90 miles south of Buf.
Before everyone gripes. The photo attached is the jig I use. Nuttin' fancy. 2 paint can tops that telescope into each other with a wrap or so of tape to take up the slack. And the dimples in the center to poke a few holes and stick a dowel in. You could use a measured and cut fiberglass driveway marker stick. I used wood. And. It's RF transparent.

When I setup a big dish. Paramount. Aim the lnb at the dead knutz center of the dish. Make absolutely sure that the dowel does not protrude into the lnb anywhere close to the probes inside.

Everything works around getting as best of a signal with the lnb aimed at the dish center. Do what is needed to your aim to get the best possible signal. Even if you have to move the lnb around a touch to get the first hint of a signal to let you know you're close to an aim. Tweak the dish position until the lnb is aimed as close to dead center.

Mike says it! You tune to a horizontal (or vertical) transponder. Get get your signal strong as you can.
In/out a bit with the lnb. Left/right on the skew. As strong of a signal as you can get. Snug the 3 bolts a little. Do not crush the lnb waveguide throat. Watch your signal as you snug it up. It will waver. Do what you need to do to keep the signal high. Sharpie the lnb and scalar (super fine point) so you have a reference mark.
If the lnb is sloppy in the fixture. Try a few wraps of aluminum hvac duct tape. Helps shore it up and the screws something to dig into.

Switch to the opposite polarity on a transponder. How's your signal? Lightly loosen a holder bolt and without moving the lnb in or out. Turn it in the holder/scalar left ot right and see if your signal increases. Peak it. Snug it down again.
Pay attention to your sharpie mark. You only want to turn the lnb. And again. Watch the signal when you snug the perimeter bolts/screws. BTW. I file the ends of the stainless screws on mine flat. Less tendency to walk he waveguide.

Switch back to the other transponder (opposite polarity). Make a tik mark with the marker where it currently is.
Then lightly loosen the lnb and see if turning it left/right a tiny bit increases the signal.
Since you're in the unknown land I'll give a few transponders on 101 you can use that seem to have close to equal signal strengths.

Don't fight aiming your lnb on a prime focus dish that is not aimed directly at a satellite. It takes a lot of time.
Then you can work on your tracking with elevation/declination. Just got done doing the finals on mine. I get the elusive 115 I looked for like Pluto. It's weak. But I snagged it.


TP SNR

4005V 84%
4020H 89%
4030V 76%
4048V 83%
4060H 77%
4080V 80%
4100H 81%
4120V 80%
4140H 65%
4160V 87%
4180H 90%


....."happy hunting, mr. vick!"

 

[tiredold]

Thank you, very interesting. But I thought this was not necessary for a LNBF. I will try going up again. It was a little tweaking with the LNBF that got the horizontals. I think the LNBF may have moved in the holder. I think 101 is super fussy. It takes me 2 days to drag the cherry picker into position. I just put it back on the trailer.

 

[arlo]

Well I was questioning if 101 was a bit "fussy" also. Which made me go back and check it all out before the snow flies and my fingers freeze off.
Seems like I can skim across 97, 99, 103, 105 and past with real good signals. 101 on the other hand appeared like It's arc ( I don't remember....wait. Just pulled up my tracking drawing) is just a touch higher in the sky than the others. Just a touch. But still. So right now I can get 58W-127W. With 61, 84W being very weak as well as 115.
For me there's a "dead man's land" from 61-84. If anyone reads this in the Rochester/State College PA area and catches signals on sats in between, That would be cool to know.

Not sure what you consider unnecessary. I zoomed way in and see you have a buttonhook feed. Like me. Dead center on the dish center. Scalar first and then the lnbf. Importante'. Variances like the stick-out of the lnbf throat from the scalar.
Yeah. I know. The numbers. f/D. Good starting point and an absolute probably with rim strut mounted scalars.
If you can attain high signals and the lnbf throat is sticking out around 1/2"-3/4". Good starting place.
Sorry. Those stamped numbers on the lnbf and all the calculations. Get the best focus on your dish and then check stick out. Then adjust the scalar to compensate. AvE on youtube is famous for saying 'focus, you f***'.

Hellyeah. Skew angle is super important. Tight focus. Make Sharpie marks. Alternate between equal strength transponders. Split the difference from turning the lnbf cw/ccw to get the highest signal from each tp.
And yeah. Tightening the perimeter screws on thin walled feeds effects signal. Just tightening them can cause the feed to "walk" just a bit and lower signal levels. Don't know what else to say. Maybe I shouldn't.

 

[clucas]

If I remember correctly, there was a post about the METV mux and shortly after that I lost it too. The solution that worked for me was to move the feedhorn closer to the dish in spite of what the calculations indicated. There was no adverse effect on the other transponders so I left it there. Can’t hurt to try.

 

[arlo]

Oh. No. Have you ever owned or used a telescope? Well, in essence you have a radiotelescope. And just like an optical telescope. There is a focus adjustment. In our case it's the distance of the feedhorn throat from the dish where microwaves from the satellites out there in space are reflected in a tight spot. Instead of the retinas of your eyes to focus light on. The metal probes in the feedhorn are the target. In layman's terms.
I've told you how it needs to be done. Numbers are to get you close. There is no focus rack for an eyepiece like on an optical telescope. Or "real" camera for that fact with a focusing barrel on the lenses. Your hands and eyes looking at a signal meter tell you when you get the strongest signal. If you've been going by numbers in a pamphlet, you're doing it all wrong. All I really can say.
A dish up in the ethers is going to be difficult to tune. Like yours. Very difficult.
Strongest signal with the lnbf aimed at the dish center.
Turn the actuator a touch E or W to find strongest signal.
Adjust elevation/declination to get a stronger signal.
Tweak the lnbf again. Find the center of rotation (skew) where H & V signals are equal for equal strength transponders. Snug it all up.
Check dish tracking. Use the graphic chart posted here to figure out how to correct mis-tracking across the arc.
Once you get the lnbf focused. It stays there. Everything else goes around getting the dish to track satellites as close as you can. Trust me.
There are a few "inclined orbit" satellites that don't play very nice.The rest? They track very well with the polar mount.
METV? On 101 4180? At 90% it's blasting in here with Hogan and Klink going at it.

 

[tiredold]

Here is something to think about!! I retweaked everything. After a conversation with Brian (thanks again) I learned the sensitivity of skew on an LNBF. I changed the skew and now the vertical and horizontal have 72% quality. But 4180 H was still not locking in, even with 69% quality. It was late, so I went to bed. In the morning, there was 4180 H at 72% and clear as a bell. Held good until the evening when it broke up. Checked again around 4 am and everything good. Has held for 3 days now. THEN IT REMINDED ME. About 20 years ago, Bell only had a couple of HD channels. They would work great, until (mainly in the evening) I would lose them. I had a Bell dish 500 equivalent (82 and 91 on the same dish). Signal strength was steady at 98%. After several tech support calls, I got to level 3 support. They asked me to come in and bring my data. It turns out that my dish is fine, BUT I am 2 miles from Downsview airport. A "decomishoned" airport that now is home to Bombardier (maker of the Canada Regional Jet). At night they take the recently completed jets out to the runway and start the up and do engine tests. They also take them up for a test flight. THAT is when they fire up their radar!(and only then). It turns out that my Bell dish would have its signal "blinded" by the overiding radar signal and then would have to reacquire and lock the bell signal again. Kind of like looking into high beam headlights and then "seeing" other cars again. I changed to a narrow beam commercial dish for each of 82 and 91 (shielding out the radar sweep) and it has never happened again. Signals on 103 and 105 are to perfect to make me further question 101 alignment. I am going to watch things (pun intended) and put a specturm analyzer (I have to dig it out ) next time it goes wonky. If you have any opinions, please let me know. Thanks again.

 

[arlo]

You sparked a memory from when I lived in Athens in the 70's. I stocked shelves after school at the Exchange to save up money to piece together a stereo. I didn't make much only working a few hours a day and on weekends. Dad, a USAF CMSGT, kept picking my brains. How much I've saved, what I had my mind on getting at the time. It seemed like I saved every cent forever. There's a cool other story. Bottom line, I got it! Finally.
We lived right off base above a boat builder. The epoxy resin smell was overwhelming when they were building.
The airport radar was in visible range in red and white turning perpetually. I hooked up the dipole antenna that came with the receiver to see if anything was on FM. Every single time the antenna would spin in my direction. Yu could hear the transponder pulses in the speakers. *Bzzt*...........*Bzzt*. It was cool. Only one FM station there back then. And bouzouki music ain't nuttin' to write home about.
But. I looked quickly at the aircraft and airport radio frequency and transponder allocations. Radio altimeters creep into the c band spectrum. I guess there may be ku and ka emissions also. But still.

What happens if you were to put a little tension on a couple of the guy wires coming from your feed to rim? Signal change? I sounds like you have 103 and 105 tweaked well. What about 99?
Also. Did you strictly adhere with the f/D scale on the lnb in relation to the scalar position? What is the "stick out" of the lnb throat from the scalar ribs? If it's not around 1/2"-3/4" (more like flush with it). I'd pull the scalar back a touch and then focus the lnbf again. And I mean focus it for best signal and screw the scales. See what happens.
I'm surprised you didn't realize that skew was paramount in getting a good signal and signal balance between H &V transponders with close to equal reception strength.

Over on Rick's a fellow questioned 101 signal strengths. I've just finished tweaking my dish to track the arc and getting a twin lnb orthomode feed aligned for the best I can. I posted the signals I get on it. It was in a light drizzle and heavily overcast and misty. Today it was worse and I lost a few tenths dB. On a clear starry night I could probably gain at least a whole dB or more.
Also. Just because. Not very wise to try to tune a feed to a misaligned dish. I point my feed exactly at the dish center. Grab a signal. Align the dish to get the best signal there. Then do the feed tweaks. A good test for you with a buttonhook is to try to give it a little swing on the mount to see if your signal rises.