Initial Testing Of Norsat C-Band LNB 3420

[Christopher Cromwell]

It has barely warmed up enough outside for me to begin my next C-Band project. Never one to be called a "Settler", I'm testing two Norsat 3420 LNB's bolted to a Chaparral 2 in 1 Feedhorn; that's affixed to my motorized 1.2M dish using a metal Geosatpro LNBF Clamp. I'm still in the initial testing stages using my Manhattan 1997 receiver, and so far it is performing better than originally expected. It has been very cloudy, stormy and rainy here for the past week, but somehow the signals are still coming in between 54%-65% quality on various channels and satellites. I figured the feedhorn would be too short to use on this dish, and the signals would be very low to none initially. I still have to take pics and run more tests with other receivers.

Initial tests on the 1997 receiver show that I do NOT have to set individual polarity Sats as long as I am using a Polarity Multiswitch from Geosatpro. I can leave the setting on 13/18V and it will blind scan both polarities as before. I have blind scanned two satellites and both polarities come in with lots of channels. I want to wait for a clear sunny day to finally blind scan for real results.

Yes, the whole LNBF apparatus sags down the 1.2M dish with the extra weight, so you have to compensate by raising your dish elevation while checking your meter(s). It's best to have two individual meters for each LNB Polarity to make sure both are being dialed in at the same time correctly; the batteries will drain quickly however. The Satlink meters will show a low Signal Quality reading at first, which had me concerned, but later the TV showed a much different signal strength. I will probably have more tweaking to do in the near future.

Let me know if your interested in what I find, and I will make a new thread later on as time allows. If not, it's no big deal.

 

[Jason S]

Very interesting project. Do you have any photos of the setup?

 

[Christopher Cromwell]

Very interesting project. Do you have any photos of the setup?

Hey Jason! I have a few pics taken so far of the items I used. I haven't had time yet to take pics of my 1.2M dish with the Norsat LNB'S assembled or screen shots of the signal readings. I meant to take pics of my dish earlier today, but got busy with tweaking, experimenting and fine tuning; before having to go to work. It was a very rainy cloudy day, the Signal Quality went down a percent or two on some channels, but still watchable. Some channels wouldn't come in at all, but that could be the weather or something else. These LNB'S seem to bring the signal IN, even two degrees away.

 

[Christopher Cromwell]

These are the pics I took so far. After I take more pics, I will start a new thread and put everything there.

 

[Mr Tony]

Why not leave it in the same thread so we can all follow along?

 

[Christopher Cromwell]

Why not leave it in the same thread so we can all follow along?

Ok, I definitely could do that too. I was thinking of the same thing, but I didn't want to get anyone all upset for making one long thread about several different things going on. I am hoping Spongella might find this thread interesting too, if he finds it.

 

[mmewrench]

Ok, I definitely could do that too. I was thinking of the same thing, but I didn't want to get anyone all upset for making one long thread about several different things going on. I am hoping Spongella might find this thread interesting too, if he finds it.

Are you powering the lnbs with the manhattan? I use norsat plls on my BUD and they are power hungry (3420s are pll). I found that they work best with 20 volts DC. You may have better results using power inserters for each lnb. Add them after the switch because the current will toast a switch in short order. I'm using a 3120 but 3420 is similar, and I can lock a signal with 10% quality or less in some cases.

 

[Christopher Cromwell]

Are you powering the lnbs with the manhattan? I use norsat plls on my BUD and they are power hungry (3420s are pll). I found that they work best with 20 volts DC. You may have better results using power inserters for each lnb. Add them after the switch because the current will toast a switch in short order. I'm using a 3120 but 3420 is similar, and I can lock a signal with 10% quality or less in some cases.

Currently with the initial tests, the Manhattan 1997 is powering both LNBs, polarity switch and dish motor without any external power source. I was at first preparing a way to run external power in case I needed it, but it seems to do fine on its own so far. I don't plan to run the motor much, its usually parked on 58W for NHK World. This may not always be the case for other low current receivers like the Manhattan 1933, but I haven't gotten that far yet. I bought two Norsat 3120 LNB's I was going to use first, but figured the 3420's would perform a tad better with my 1.2M dish. I might sell the 3120 LNB'S on Ebay sometime later. I kept forgetting to mention earlier that these are PLL LNB'S which why I wanted them so bad. I will agree with you that an external power source might be recommended however.

 

[danristheman]

Keep up the good work Chris can't wait for the final results.

 

[Christopher Cromwell]

I got home late Saturday afternoon and immediately went to work on my C-Band project. It was a clear sunny warm day for once in weeks. I spent most of the time trying to make sure I had the signals as even as possible for both polarities adjusting the Dish Elevation. I thought I had it lined up perfect earlier, but it seems the elevation might now be a little too high, as 58W doesn't come in too good at all like it used to. I guess I should have left well enough alone on that. :-/ I will have to work on it more when I have another sunny warm day off. After I readjust the Dish Elevation and double check the signals again, I will move on with testing other receivers and blind scans.

If I have the Chaparral Feedhorn turned the wrong way, please let me know. Somehow, the top LNB is functioning as Horizontal and the bottom LNB is functioning as Vertical, which is very weird working backwords. I have made sure the cables from the Polarity Multiswitch are going to the correct LNB. I have never used a Chaparral Feedhorn before, so not entirely sure if I have it set correctly.

However the Manhattan 1997 receiver is still receiving the signals the same way as normal. Here are some pics I took earlier.

 

[Christopher Cromwell]

The more I think about it, the more convinced I am the Feedhorn is skewed around the wrong way; as Eugene at Geosatpro tried telling me over the phone. I will have to fix it later and see how the signals do.

 

[mmewrench]

The more I think about it, the more convinced I am the Feedhorn is skewed around the wrong way; as Eugene at Geosatpro tried telling me over the phone. I will have to fix it later and see how the signals do.

That is an easy fix. Just reverse your switch settings. I haven't used an ortho feed, but it stands to reason that if one lnb is skewed straight up at true south (vert), the other will be horizontal.

This may be a good solution for lnb power. I would use one for each lnb (considering the cost of the lnbs the power inserters are cheap insurance for the lnbs and the receiver).

http://www.ebay.com/itm/151282736424?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

 

[Christopher Cromwell]

That is an easy fix. Just reverse your switch settings. I haven't used an ortho feed, but it stands to reason that if one lnb is skewed straight up at true south (vert), the other will be horizontal.

This may be a good solution for lnb power. I would use one for each lnb (considering the cost of the lnbs the power inserters are cheap insurance for the lnbs and the receiver).

http://www.ebay.com/itm/151282736424?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

Ok, I have reversed the voltage settings, but that didn't seem right either. Eugene at Geosatpro told me that it's not a Disecq Switch so there's no settings to change in the menus; it's all automatically done in the multiswitch itself. He told me I need to rotate or skew the whole Feedhorn around to the left or right 90 degrees, so the polarity lines up correctly; I think he is correct on this, I need to try it. I wasn't quite exactly understanding at first, I thought I had it set right. I will have to work on it later when I have good weather after work. It might make a difference in the signal quality and I have to recheck the dish elevation too.

 

[waylew]

Just swap the wires,either at the switch or the lnb's.The way you have it set now,the top lnb is the horizontal.If you look down the throat of the feed horn,you should see the probe (actually the antenna) of the top lnb is in the horizontal plane - .

 

[Christopher Cromwell]

Just swap the wires,either at the switch or the lnb's.The way you have it set now,the top lnb is the horizontal.If you look down the throat of the feed horn,you should see the probe (actually the antenna) of the top lnb is in the horizontal plane - .

That's actually how I have it set now, I switched the cables around at the multiswitch; so the polarities are working correctly. Just doesn't look right though. :-/ I could just leave it as it is too, just wasn't sure if there would be much of a difference in signal quality messing with it or not. But I do now see what your describing, the feedhorn had a small metal tube inside covered with plastic, theses no documentation telling me what the correct orientation is. I appreciate your help so far.

 

[waylew]

Based on how you have it oriented in your picture.The plastic tube is the vertical probe that transfers the signal down to the bottom lnb,probe I,lnb antenna I.The signal for the top lnb goes straight thru the feed horn to the lnb antenna which, the way it's attached to the feed,is positioned like this -,so horizontal.

 

[Christopher Cromwell]

Based on how you have it oriented in your picture.The plastic tube is the vertical probe that transfers the signal down to the bottom lnb,probe I,lnb antenna I.The signal for the top lnb goes straight thru the feed horn to the lnb antenna which, the way it's attached to the feed,is positioned like this -,so horizontal.

Ok, yes!! You provided me the answer I need! Thumbs up!! -D I kept originally thinking that small metal tube was for horizontal signals, so I do have the LNB'S bolted corectly on. According to my pic, I just have the whole thing rotated upside down! All I have to do is swap the cables back around and rotate the feedhorn until the horizontal LNB is back on top! I can also play with the focal depth of the feedhorn to see if signals improve, since I will have alot more room to do this. The Chaparral website and Google is little to no help. :-/ Couldn't even get Chaparral to answer the #%€(\÷ phone! :-(

 

[waylew]

No,if you rotate 180 to put the bottom on the top you're exactly the same as you are now,polaritywise.If you want to change the polarities of the lnb's you need to turn it 90,so they are side by side not over and under.

 

[Christopher Cromwell]

No,if you rotate 180 to put the bottom on the top you're exactly the same as you are now,polaritywise.If you want to change the polarities of the lnb's you need to turn it 90,so they are side by side not over and under.

Ooops! Ok, gotcha!! :-D That's what Eugene from Geosatpro told me earlier too, he would tell me the same thing. Yes I would be back to being frustrated turning it 180 degrees. Ok, I will turn the feedhorn just 90 degrees so they are side by side. I will still have some room to adjust the focal depth and see how the signals do. I will post new pics of the corrections. I guess I won't need to swap cables back around either.

 

[waylew]

It really doesn't matter which way you have them,as long as whichever lnb is in the vertical plane is connected to the vertical port and the horizontal is hooked to the horiz port.