First time installing C-Band dish (8ft)

[stef]

Hi All,

I've been a long time reader of these forums and for years I've always wanted to get a C-band dish (took a while to convince my wife. she says the black-mesh actually looks nicer than my 1.2m KU one!).

I'm at 45.5 latitude so if I calculated right, I need the following:

Latitude 45.5'
Modified Lat. 46.16'
Declination 6.23'
Total 52.39'

I got a Tek2000 8-footer mesh dish and, unless I built it wrong, my declination screw isn't long enough for a 6.23' declination. I bought a long 1/2" SS thread rod which i cut a 7" section that I'll use.

While I wait for a sunny day to switch the screw... I'd like to find which true-south satellite/transponder to use at the top of my arc for tuning/tweaking.

My long. is ~74W so I was wondering if there's any transponders on 72W AMC 3 that I could use for tweaking? If not, what would be the next best sat/tp?

Thanks,

Steph

Edit: I forgot to mention that i do know that lyngsat lists nothing off AMC 3, just want to be sure there's really nothing coming out of that bird... thanks.

 

[FTA4PA]

Hi All,

I've been a long time reader of these forums and for years I've always wanted to get a C-band dish (took a while to convince my wife. she says the black-mesh actually looks nicer than my 1.2m KU one!).

I'm at 45.5 latitude so if I calculated right, I need the following:

Latitude 45.5'
Modified Lat. 46.16'
Declination 6.23'
Total 52.39'

I got a Tek2000 8-footer mesh dish and, unless I built it wrong, my declination screw isn't long enough for a 6.23' declination. I bought a long 1/2" SS thread rod which i cut a 7" section that I'll use.

While I wait for a sunny day to switch the screw... I'd like to find which true-south satellite/transponder to use at the top of my arc for tuning/tweaking.

My long. is ~74W so I was wondering if there's any transponders on 72W AMC 3 that I could use for tweaking? If not, what would be the next best sat/tp?

Thanks,

Steph

Edit: I forgot to mention that i do know that lyngsat lists nothing off AMC 3, just want to be sure there's really nothing coming out of that bird... thanks.

Welcome to Satellite Guys Stef! Glad to hear you were able to convince your other half on a c band dish. She should be pleased with the selection of channels available. I had one of their first 8' mesh dishes when they came out. Can't remember if I used the original declination bolt or added one but here is a picture of it.



I'm just shy of 77W here and remember using 72W when I setup my first c band dish a few years back. Sadly, I don't believe there are any channels there now. There are active channels on 78W @ 3885 V 23000. The signal is not real strong but I was able to lock them with a TEK2000 8' mesh though. From the look of the footprint at Satbeams.com they are even weaker at your location. Best bet is probably 87W 4140 V 29125. Luken mux is a good strong signal and should be fairly easy to find.

 

[stef]

Thanks FTA4PA for the warm welcome.

I was thinking of using washers as well... my only issue was once all installed and during the tweaking phase, it'd be a real pain to adjust the declination.

As long as I get a detectable lump on EBSPro's RF Scan, i'll be happy. I have a C1-PLL (bought years ago to attempt mini-BUD), so hopefully I can see something... it's really more for positional mapping. Tweak @ 78W, then move to 87W (which is a bit far from my true-south/peak arc).

I wasn't too crazy about the lower pivot bracket being straight so I bend it so that it wouldn't put too much pressure on the brass bushing. Having it bent shouldn't cause any alignment issues right?

Sun is supposed to come out tomorrow, hopefully i'll have time to work on it.

Cheers,

Steph

 

[FTA4PA]

Thanks FTA4PA for the warm welcome.

I was thinking of using washers as well... my only issue was once all installed and during the tweaking phase, it'd be a real pain to adjust the declination.

As long as I get a detectable lump on EBSPro's RF Scan, i'll be happy. I have a C1-PLL (bought years ago to attempt mini-BUD), so hopefully I can see something... it's really more for positional mapping. Tweak @ 78W, then move to 87W (which is a bit far from my true-south/peak arc).

I wasn't too crazy about the lower pivot bracket being straight so I bend it so that it wouldn't put too much pressure on the brass bushing. Having it bent shouldn't cause any alignment issues right?

Sun is supposed to come out tomorrow, hopefully i'll have time to work on it.

Cheers,

Steph

Yes, I remember having to disassemble the declination adjustment a few times until I got the best signal. I was going to use two thin nuts between with no washers because two full size ones were too thick but in the end I choose the large washers because they seemed to make things more 'solid'. I kept my lower pivot bracket straight and have had no issues in three years but don't see any real problem with putting a little bend in it. Be sure to grease everything really well with something that can take the cold weather. The C1-PLL is a solid performer. I use them myself and am very pleased with them.

 

[stef]

Ok, so using washers, the closest I could get to my declination angle was less than .5 of a degree. Is that ok or do I need to be dead on?

I also did the string test and my panels are pretty flush (the strings were touching, but not pulling/pushing against each other).

Time for some simple math...

Tek2000 tech. specs:

Diameter (D): 90"
Focal Length (f): 35.75"
f/D: 0.40

Measured by me:

Diameter (D): 89.5"
Depth (c): 13.25"
Focal Length (f): 35.25"

If I calculate the focal length and f/D ration from D and c, I get the following: f = (D*D) / (16*c) = (89.5*89.5) / (16*13.25) = 8010.25/212 = ~37.75"... f/D = 37.75 / 89.5 = ~0.42

Did I calculate this right? With the above differences, 37.75" (calculated) vs 35.25" (measured), will I have to move my arms to another location? I still haven't started satellite hunting... will probably try after work.

Thanks,

Steph

 

[KE4EST]

to SatelliteGuys!!

Start with what you have and hunt around for awhile. If nothing then, you may have to move your arms. I don't know about the 8 footer but on their 10 footer I had to move the arms down. Fought with it for a couple hours before. Did some simple calculations and decided to move the arms. When I did got a signal almost instantly. Of course I have been doing this for awhile and had a descent Sat meter.

 

[FTA4PA]

Ok, so using washers, the closest I could get to my declination angle was less than .5 of a degree. Is that ok or do I need to be dead on?

I also did the string test and my panels are pretty flush (the strings were touching, but not pulling/pushing against each other).

Time for some simple math...

Tek2000 tech. specs:

Diameter (D): 90"
Focal Length (f): 35.75"
f/D: 0.40

Measured by me:

Diameter (D): 89.5"
Depth (c): 13.25"
Focal Length (f): 35.25"

If I calculate the focal length and f/D ration from D and c, I get the following: f = (D*D) / (16*c) = (89.5*89.5) / (16*13.25) = 8010.25/212 = ~37.75"... f/D = 37.75 / 89.5 = ~0.42

Did I calculate this right? With the above differences, 37.75" (calculated) vs 35.25" (measured), will I have to move my arms to another location? I still haven't started satellite hunting... will probably try after work.

Thanks,

Steph

I believe when I got mine the specs gave a f/d of .40 but after measuring the dish and doing the calculations it was actually .38 so that's what I set it at and it worked. My lnb support arms mounted on the outer rim of the dish but I believe newer models changed the mount point to the face of the reflector. There have been several improvements since these dishes first became available and I'm not so sure the specs are up to date so I wouldn't worry too much about them. Like KE4EST said, give it a shot like it is and see what you get. If needed, you have the calculations already done to correct things. Most important is to not stress yourself out and just have fun - things will come together!

 

[wvman]

I believe when I got mine the specs gave a f/d of .40 but after measuring the dish and doing the calculations it was actually .38 so that's what I set it at and it worked. My lnb support arms mounted on the outer rim of the dish but I believe newer models changed the mount point to the face of the reflector. There have been several improvements since these dishes first became available and I'm not so sure the specs are up to date so I wouldn't worry too much about them. Like KE4EST said, give it a shot like it is and see what you get. If needed, you have the calculations already done to correct things. Most important is to not stress yourself out and just have fun - things will come together!

It would be nice if they went to button hook feeds with a little extra tube sticking out the back of the dish. It would make it easy to tweak the polarity and focal length with the dish pointed at the higher satellites. UFI did that with their fiberglass 1 piece dishes, and even some companies did that with their wire mesh dishes. Takes a lot of the trial and error out of tuning the dish.

Gets to be a pain in the butt running the dish up and down and cuts the need to stand on a step ladder trying to do it. I've seen the printed specs off quite a bit on some dishes over the years. Always took it on myself the do the calculations. Unimesh's quad feed dishes had much larger tube diameters with holes in each end so you could feed the cables inside the tubes. Liked that.

 

[stef]

Well, first attempt at finding a satellite wasn't much of a success.

Without knowing where I'm pointing, the highest TP I could find was 4040 H 34286 and 4100 V 30000... possibly on 91W?

I attached screenshots of EBSPro's BS Mode and SA. TSReader just gives TEI errors...

Tried pulling the dish slightly up/down/left/right, didn't really improve the signal.

Tried moving the LNBF in and out but, again, no change in signal.

Tried rotating the LNBF's skew, I think I lost signal after a certain threshold (probably makes sense since I was looking at an H TP).

As for the RG6 connectors, I use Snap 'n Seal, hopefully it isn't anything other than dish alignment and/or focal length.

Steph

 

[wvman]

Well, first attempt at finding a satellite wasn't much of a success.

Without knowing where I'm pointing, the highest TP I could find was 4040 H 34286 and 4100 V 30000... possibly on 91W?

I attached screenshots of EBSPro's BS Mode and SA. TSReader just gives TEI errors...

Tried pulling the dish slightly up/down/left/right, didn't really improve the signal.

Tried moving the LNBF in and out but, again, no change in signal.

Tried rotating the LNBF's skew, I think I lost signal after a certain threshold (probably makes sense since I was looking at an H TP).

As for the RG6 connectors, I use Snap 'n Seal, hopefully it isn't anything other than dish alignment and/or focal length.

Steph

Usually it's something simple. I had a head scratcher last evening. I found a listing showing THIS on 125W. I wanted to move one of my dishes that still has an actuator on it to see if the signal was better than on 99W. The dish I moved was parked on 97W, so I moved it to locate the channel on 125W. I found it, checked the signal level and when I moved it back, I landed on another satellite instead of 97W.

The weird part was that every channel in the 3940 MUX, LAFF, Justice etc, had signal, but no picture. At first, I thought the receiver had a glitch, but it turned out to be on the wrong satellite. I've had that happen with one or two channels, but never an entire MUX. Just one of those weird incidents. In your case, it's easier to see what channels are active on the target satellite, then manually program the channel information in the receiver, and use that channel to tune the dish.

It's easier than using a meter because the channel will pop on when you hit the satellite. I have meters, but I usually program the channel and then locate the satellite. Just a suggestion that works well for me. After you locate it, then you can tweak the dish for best signal. I move the dish in very small increments until I locate the correct satellite, and then make the fine adjustments. Hope that's helpful.

 

[KF4YLM]

I have found false images like that before. I scanned the arc with a spec an, noting positions with signals, then told the STB to go check them out. Turned out, along my Eastern limb, what I thought were low horizon birds were images of higher longitude birds.

Its tough -- nigh near impossible - to make a reflector antenna whose pattern is 100% clean and free of lobes, spillover, etc. It was a good demonstration, above, of how Wiley things can get. I need to do some checks myself to see if there are physical distortion s on my antenna that I can fix and clean up my pattern a bit.

Mine is an old 10' Unimesh Piece Of Salvage.

 

[stef]

Ok, so it turns out my true-south was bad. I moved it by reference to where I think it should be and now I'm getting feeds without TEI errors from 87W.

Attached is the result of my first blindscan from 87W. Can someone have a look and report if it's "ok" for an 8ft? I'm located in the greater Montreal area. I'm unable to lock onto the 3980 V 34000 DVB-S2 5/6 16PSK transponder.

This weekend, I'll plant a stick in front of my dish and monitor the sun's shadow at the proper time to get the best true-south... I'll also play with the LNBF. Hopefully both will result in a bit higher RFLevel.

PS: After years of trying to convince my better half that I *need* a big dish and that an 8ft is probably the best I could squeeze. She said it's nicer than my old 1.2m one and then she said I should have gotten a bigger one!! Doh! Maybe next year...

Cheers,

Steph

 

[stef]

Just a quick update. After I found the 87W satellite, I spend the rest of the evening programming my vbox. Looks like my arc is from 43.1W to 116.8. I might be able to touch a few more eastern birds once I readjust my east-limit on my actuator. West-wise, I think my house is in the way.

All and all, not bad for starters. I still need to really fine-tune it and the LNB.

Steph

 

[stef]

FTA4PA, can I ask you for a favor? Can you measure your Tek2000 8ft LNB support legs? I see that yours were mounted on the panel rim, while mine didn't have any holes on the rim but there were some about 5" inside. Using these didn't get good result so I located them 7" inside which seem to have given me better result but there are some satellites that I have trouble pulling... it could be my elevation/declination angle.

Try measuring from bend to bend (i.e. from the rim edge to the scalar ring edge). If yours and mine are the same length, I might try testing my legs located on the rim (using some metal wire so not to make too many holes on my dish)

Thanks,

 

[bpalone]

I'm not FTA4PA, but I have/had one of their early 8 footers, too. Just measured and about 47 1/8 from where round ends on both ends. Mine had bolted on the outside edge also.

Edit: Did you set the LNB throat where your math indicated? I don't know about the newer 8 footer, but the 10 footer requires some of that math and appropriate adjustments. If you had it set where your math indicated, then would guess skew or still just a bit out of adjustment. That is assuming all measurements were correct and proper math employed.

 

[FTA4PA]

FTA4PA, can I ask you for a favor? Can you measure your Tek2000 8ft LNB support legs? I see that yours were mounted on the panel rim, while mine didn't have any holes on the rim but there were some about 5" inside. Using these didn't get good result so I located them 7" inside which seem to have given me better result but there are some satellites that I have trouble pulling... it could be my elevation/declination angle.

Try measuring from bend to bend (i.e. from the rim edge to the scalar ring edge). If yours and mine are the same length, I might try testing my legs located on the rim (using some metal wire so not to make too many holes on my dish)

Thanks,

Mine have a total length of 49.5 inches tip to tip. From the bend on the rim of the dish to the bend at the scaler is just under 47.25 inches, so very close to what bpalone has on his.

 

[stef]

Thanks. I just measured mine they are 44" from bend to bend so it would make sense that they aren't installed on the rim.

I must have messed up my hole position yesterday when I went from my temporary leg tying (using aluminium wire). I went from a total of 29 TP found on the 14th to 15 today on 116.8W. Yet, I find a total of 20 TP on 107.3W... but that could be because the footprint is strong in easterna Canada.

Ah, the joy of dish tuning... really need to take half a day off and tune it without the kids being around.

 

[luke rizzuto III]

Look at lyngsat.com america between 87and 139 degrees... prly should be a bigger dish