Can you walk me through how this is determined? Is there an "offset dish for dummies" book? The info I've come up with doesn't explain things clearly. I need to be spoon fed more. But I'll set it for 14.6 since my true south elevation is suppose to be 41.9 (this is my latitude to 1 decimal place). So, 41.9-27.3=14.6. I don't know how accurate this adjustment needs to be to pull in a C-band signal though. Hopefully, it's close enough.
new 1.2 meter dish and 12 footer
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Can you walk me through how this is determined? Is there an "offset dish for dummies" book? The info I've come up with doesn't explain things clearly. I need to be spoon fed more. But I'll set it for 14.6 since my true south elevation is suppose to be 41.9 (this is my latitude to 1 decimal place). So, 41.9-27.3=14.6. I don't know how accurate this adjustment needs to be to pull in a C-band signal though. Hopefully, it's close enough.
It's all there, I believe. Just read carefully.
This means that at elevation 41.5, you hit the beam towards the satellite-arc, at due south!
But as you have an offset dish, the dish face 'aims' lower than the beam:
BTW Don't mix up axis elevation for the motor,
and total elevation for the dish and beam.
I don't understand zilch from your sentence:
Greetz,
A33
I don't know where you got that figure for modified axis elevation.
You're talking a "foreign language" now. I'll have to get some in-depth info to understand what you just wrote.
My understanding is if there were a satellite at true south the elevation would be 41.9 degrees while the elevation for 103W is 41.6 degrees (according to dishpointer.com). So, the offset dish should be set to 41.9-27.3=14.6 for true south? Regardless, would 0.4 degree difference between my calculation and yours make that big of a difference?
I (in post #18) got it from you, post #15.
Where did you get the value 42.7 from, yourself? (It would be correct, for modified latitude angle at LAT=42.0, so I gladly used it.)
You'd better. Understanding that the axis has an elevation due south, and that the satellite beam and dish have another elevation due south, is rather important.
You could read the old COOPs CSD magazine, april 1981 page 3, but don't forget to FIRST read the erratums in june 1981 page 3, or you might get confused even more....
The top of the arc is pretty flat.
In dishpointer.com, choose Motorized Systems, True south/north, and you'll find 41.6 arc elevation for LAT=41.9, or 41.5 arc elevation for LAT=42.0
I hope this helps a bit.
Greetz,
A33
42.7 came from a couple of charts. I actually calculated it from the tables to get as precise as I can get for my latitude of 41.8775. The charts had figures for latitudes 41 and 43.
I went with 41.6. The inclinometer showed 14.3. I couldn't get a hit on 103W but it looks like I'm getting something on 101W but I couldn't get a solid lock on any of the transponders. One transponder was jumping between 0 and 3 C/N. Lifting the dish lip up or pushing down made no difference and adjusting the feedhorn didn't help either. I suppose I can try moving the mount east or west after it cools down a bit. The XR-3 Sat ID function identified it as 101W the first time but subsequent ID searches came up with 105W and 123W. I'm reasonably certain that it's 101W considering the antenna is pointed east of true south (true south determined from solar noon). Anyway, I won't leave a solid dish on my lawn again since the metal got so hot that it burned the grass underneath.
Go for the FETV mux (Lesea) on 99w. IF you can't get that rock solid on a 1.2m that's well tuned, you might as well give up trying on any other satellite. That mux is easy to get.
Looks like an 18" actuator is inadequate. Can't get east of 95W. Not sure about how far I can get to the west but it doesn't look like it'll get anywhere near 121W. Doesn't sound like it'll get west of 115W. Jury is still out on whether or not the 1.2 meter will be acceptable for C-band.
I replaced the 18" actuator with a 36" and can see more of the arc now. So far I have 91W to 101W programmed in. Of course, not all services get scanned in. I did have a bad C1W-PLL that wouldn't change polarity - not sure how old it is but maybe 2 or 3 years. I need to do some more tweaking but we're going to be in the low 100's for the next 4 or 5 days.
It would be interesting to hear a summary of what you can receive on C-band with the small dish.
Sent from my SM-G950W using the SatelliteGuys app!
Sent from my SM-G950W using the SatelliteGuys app!
I wish there was a simple way without naming all services that I've been able to scan. The ones of primary interest are Univision on 91W and Azteca on 97W. Interesting that I can get Azteca on 97W but not 99W. The Azteca feed is only 9 dB C/N on 97W and I don't know if I can squeeze any more out of that - I'd like to see it above 10 dB. It does seem like the transponders are weaker on 99W for some reason even though I'm in the center of the footprint. And I get FETV and a couple others on 99W - but not the PR feeds on 4156. Anyway, I do get Heroes East and west on 101W even though the east feed is weaker than the west feed. I couldn't get Decades on 101W. So far I haven't been able to get any FTA feeds west of 101W yet.
I'm preparing here for a mini-BUD test. I just need the USPS to deliver my LNBF that has been in transit for 2 1/2 weeks. Any influence you have with USPS would be appreciated.
Attached image is an example of how I plan to document my testing for my own records. I can screen capture lyngsat then edit it lightly with my received SQ % readings.
Attached image is an example of how I plan to document my testing for my own records. I can screen capture lyngsat then edit it lightly with my received SQ % readings.
It looks like this dish isn't going to work out for me on C-band. I hadn't changed anything but now I can't get Azteca on 97W or H&I on 101W. They were coming in OK last night but not now. I tried some fine tuning but still nothing. Maybe the haze from the wildfires causing that much of a problem? Time for plan B.
Have you tried asjusting the scaler? Moving it up and down the feedhorn?
Also rotating the LNB in the holder?
Yes. They had little effect. Just a few tenths of a dB. I have another LNB but I don't know if it's a good one. I'll try that tomorrow.
Looks like it's temperature related. The signals are back. We're back under 80 degrees after a high of 97. I guess that heatsink on the LNBF can't handle the job. Tomorrows forecast is in the low 100's. Hopefully, my remaining LNBF will fare better. Stay tuned.
Nothing to do with the heat sink thermal dissipation qualities on a LNBF. 
Physics 101... Thermal noise increases and the atmosphere attenuates and depolarizes during the day and especially during the summer months. Also may be experiencing a slight attenuation by particulates ((ie. smoke and ash drifting across the continent). SNR improves during the cold season.
Physics 101... Thermal noise increases and the atmosphere attenuates and depolarizes during the day and especially during the summer months. Also may be experiencing a slight attenuation by particulates ((ie. smoke and ash drifting across the continent). SNR improves during the cold season.
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Adjusting the LNBF fore/aft in the clamp and the scalar FD position will result in MAJOR gains and attenuation. Shifting the feed fore/aft will result in severe attenuation and complete loss of the signal as the convergence point is moved outside of or deeper onto the feed opening. The scalar position typically will optimize and provide several dB variation, especially if there is adjacent satellite or terrestrial noise present.
Please post several photos which show the feedhorn position/angle, support leg placement and scalar setting. I've noted that the installer often assembles the GSP 1.2 dish with incorrect feed support arm placement when using the optional metal 65mm feed clamp assembly.
Please post several photos which show the feedhorn position/angle, support leg placement and scalar setting. I've noted that the installer often assembles the GSP 1.2 dish with incorrect feed support arm placement when using the optional metal 65mm feed clamp assembly.
After adjusting the feed in/out and polarity for maximum C/N, there was no room to move the scaler. I got 8.2 dB C/N @ -32 dBm signal strength for 3809H on 97W as measured with an XR-3.
I've attached a couple of photos. 1.2 meter is looking at 97W.
Attachments
Why is the dish rotated?
Is that the correct LNB bracket from SatelliteAV?
Is that the correct LNB bracket from SatelliteAV?
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