Continuing from where I left off. Mast issues are taken care of. On to Setting up multiple lnbf on this satellite dish. Pictures to come on my next post. Looking for others to post pictures of there multi fixed dish lnbf here.
custom multi lnb for 75e channelmaster
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The multiple LNBFs will not be installed at the same height. The offset LNBFs need to be raised and lowered to follow the arc. The refector reverses the arc. Example: The offset LNBF on the east side of the arm will receive a satellite located to the west of the centered satellite. If the adjacent satellite is a higher elevation angle, the offset LNBF will be positioned at a lower height than the centered LNBF.
You will have best performance if the centered LNBF sits with the center of the feedhorn positioned at the exact height as the center of the original feedhorn. This point wound be 1/2 of the 23mm clamp = 11.5mm above the bottom of the clamp.
You will have best performance if the centered LNBF sits with the center of the feedhorn positioned at the exact height as the center of the original feedhorn. This point wound be 1/2 of the 23mm clamp = 11.5mm above the bottom of the clamp.
I know, your absolutely right. Just not sure how to do it. Yet.... I am in the process of getting ready. I bought a 1/4 inch x 1/8 piece of galvanized steel approximately 24 inches long or more. Thinking of mounting it on the front of the dish arm. horizontal. Then mounting the new lnbf left and right of the center one. So I will replace the center lnbf "universal" with a new standard one. Then mount the remaining four. Two on each side. Total of five. I am hoping to hit. 125, 103, 97 center, 87, 83. Well. 83 if anything is still on it. Last I knew the only three channels on it were moving to cband. So if I am correct, Dish will be a 45 degrees " horizontal", 87 and 83 will not be to the left where they would be if aiming using the center lnbf but to the right.and 103 and 125 would be to the left. The far left. I am wondering if I would even hit it.
You may be able to get satellites with a minimum separation of 4 degrees, but the maximum coverage will likely be 30-40 degrees separation with the edges being significantly attenuated. On the smaller 75cm reflector, I will be surprised if reliable reception will be possible past 30 degrees separation (+15/-15 either side of center.
The North American FSS satellites are operated with a link budget at a lower power and require larger surface area to gather adequate signal. You might be able to lock 121w, but think that will be the limit. 125w will be below threshold.
The North American FSS satellites are operated with a link budget at a lower power and require larger surface area to gather adequate signal. You might be able to lock 121w, but think that will be the limit. 125w will be below threshold.
I've gotten 103, 97 and 87 W on a multi LNB setup on one of my 76cm dishes, with 87 W on the main center LNB. I doubt you'll be able to get 125W along with 103, 97 and 87W, unless 125 is the center LNB, but then you'll not be able to get the others.
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Similar to Danristheman setup - Here's something I worked on last year (thread starts here). There are several examples and links from Satguys members in this thread that proved invaluable. The dish in the photo below is a 1.2m with the center LNBF on 97W and the offset on 103W (when it still had the odd skew).
This is what the LNBF holder looked like when I got done assembling.
This is what the LNBF holder looked like when I got done assembling.
I have posted them somewhere in another thread. There are couple more
But, speaking about self-made multifeed, I can not find easiest way how to do it from cheap galvanized stuff
which is sold in any Home-Depot like shop. 
oh boy. So I was going to upload some pics I took yesterday but I am not able to do so. technical. Maybe tomorrow. But here is the thing........
I replaced the universal lnbf with a standard. This standard lnbf is one of the five I just bought. For some reason it doesn't function near as well as the universal one. At best, and this is with me readjusting and re-tuning the dish, I am getting 53% signal quality. Strength is up in the 70 range. To throw a monkey wrench in to things, I am getting more channels as well. SO..........More channels but less signal quality. REVIN is like 5 in signal quality. Terrible. I had to also re scan all the transponders and channels again. They wouldn't come in just swapping the lnbfs. Universal to standard or vis versa. I think I ran in to this a couple years ago. But I an thinking this lnbf is no where near as good in quality compared to the one I was using.
I replaced the universal lnbf with a standard. This standard lnbf is one of the five I just bought. For some reason it doesn't function near as well as the universal one. At best, and this is with me readjusting and re-tuning the dish, I am getting 53% signal quality. Strength is up in the 70 range. To throw a monkey wrench in to things, I am getting more channels as well. SO..........More channels but less signal quality. REVIN is like 5 in signal quality. Terrible. I had to also re scan all the transponders and channels again. They wouldn't come in just swapping the lnbfs. Universal to standard or vis versa. I think I ran in to this a couple years ago. But I an thinking this lnbf is no where near as good in quality compared to the one I was using.
What a pain... yesterday and night I Finally was making some head way. I am not sure why but with the multiswitch hooked up I am getting better signal strength. As far as any extra lnbf, you were right. Facing the dish I cant pick up any signal going left. Going right, I have to go higher and higher. But... the higher I go I am getting constant strong signal. I cant tell what I am aiming at. I keep blind scanning making micro adjustments. I start getting a couple h or v then nothing. I am thinking the dish will have to be perfectly horizontal. I think it is but it was getting dark. I am also of the opinion that I am only likely to get a sat from left and right only.
Some pics I took a couple days ago.
The lnbf in my hand is the universal I was initially using.
Here are some photos from an earlier setup (2009) on my 75e Star Choice dish (see below for current configuration).
Configuration (from front of dish) is 72, 79 & 83 (dual sat LNB, 83 is the centre LNB), and 89.
Few measurements which may help in placement of LNBs, 89 was 2 1/4 inches from the centre LNB (underside screw to underside screw) and 72 was 4 1/2 inches from the centre LNB (underside screw to underside screw), so roughly 2 1/4 per six degrees.
With your centre LNB at 97, you should get 103 to the right (facing the dish) and there isn't much else in that direction., and you should get 91 to the left. You might get 85 further out, but that is pushing it and the signals may not be strong enough to get most of the wildfeeds on that sat, especially the DVB-S2 signals. Instead of 91, you could get 87, but at 10 degrees off centre, LPB might not be strong enough, but that you can experiment with to determine. From my experience, getting a sat 4 degrees from another one would be difficult, though not impossible, see the dual sat LNB for 4 degree separation.
Currently my 75e is pointed at 61.5 (no coax connection right now), 72 (15 degrees off-centre, get the NBC mux, but most wild feeds I will not get unless they are strong), 83 & 87, and 93.
Configuration (from front of dish) is 72, 79 & 83 (dual sat LNB, 83 is the centre LNB), and 89.
Few measurements which may help in placement of LNBs, 89 was 2 1/4 inches from the centre LNB (underside screw to underside screw) and 72 was 4 1/2 inches from the centre LNB (underside screw to underside screw), so roughly 2 1/4 per six degrees.
With your centre LNB at 97, you should get 103 to the right (facing the dish) and there isn't much else in that direction., and you should get 91 to the left. You might get 85 further out, but that is pushing it and the signals may not be strong enough to get most of the wildfeeds on that sat, especially the DVB-S2 signals. Instead of 91, you could get 87, but at 10 degrees off centre, LPB might not be strong enough, but that you can experiment with to determine. From my experience, getting a sat 4 degrees from another one would be difficult, though not impossible, see the dual sat LNB for 4 degree separation.
Currently my 75e is pointed at 61.5 (no coax connection right now), 72 (15 degrees off-centre, get the NBC mux, but most wild feeds I will not get unless they are strong), 83 & 87, and 93.
The dish elevation angle will be set for the center LNBF satellite. The dish skew will not be rotated. The skew for each satellite will be set with each LNBF.
What is the zip code for the install location so I can run a satellite position calculator?
Set and optimize for 97w just as if you were installing a single satellite fixed dish. Next, directly connect the coax to a second LNBF and select a strong active transponder on 87w. Handhold the LNBF with proper skew on the West side of the center LNBF and watch the Signal Quality meter for any reading as you SLOWLY move the LNBF left/right/up/down while aimed towards the center of the dish.
I believe the reason no other satellites are being received is that the dish is not properly aligned for optimized reception on the center position. Everything must be perfect for this undersized reflector to work!
What is the zip code for the install location so I can run a satellite position calculator?
Set and optimize for 97w just as if you were installing a single satellite fixed dish. Next, directly connect the coax to a second LNBF and select a strong active transponder on 87w. Handhold the LNBF with proper skew on the West side of the center LNBF and watch the Signal Quality meter for any reading as you SLOWLY move the LNBF left/right/up/down while aimed towards the center of the dish.
I believe the reason no other satellites are being received is that the dish is not properly aligned for optimized reception on the center position. Everything must be perfect for this undersized reflector to work!
Here's one of my 30'' dishes. The LNB in line with the arm is on 87W, then 97W and then 103W. 103W was a real pain. As you can see in the picture, it's crammed right up against the 97W LNB.
I did like Brian suggested, set the dish up for the LNB on the dish LNB arm alone first, as if it were a regular setup for that one sat by itself, in my case here, 87W. Then handheld the other LNBs while connected to and watching my meter to figure out the general area for them.
Playing around with it, the spacing ended up being a lot closer to each other than what I'd thought it would be. In your pictures, it looks like your LNBs are pretty much straight in line horizontally with each other but if you look at my picture you'll see how 87 is on the arm and then 97 is a little higher, then 103 is even a little bit higher than 97, not in a straight line, but a curve mirroring the arc, unless the different shape of your dish makes a difference there.
Your setup looks really nice, a helluva lot neater than mine is!
A Raine, that is one of the advantages of an elliptical dish, you skew the dish so it gives you the arc a bit easier so the raising or lowering of outside LNBs is not so pronounced in relation to the plane of the dish. You can see the difference on my 75e posted above, 72 is higher than the centre LNBs (now 81 is the top of my arc so the dish skew was not much to begin with).
The reason your 97 and 103 LNBs are so close together is probably because they are so far from the centre of the dish the angle of locations are squeezed closer together. On my 80cm dish, there is a gap of about a 1/2 an inch between the outer edges of the two LNBs. Both are on either side of the LNB arm, 97 is flush against it, there is no centre LNB.
The reason your 97 and 103 LNBs are so close together is probably because they are so far from the centre of the dish the angle of locations are squeezed closer together. On my 80cm dish, there is a gap of about a 1/2 an inch between the outer edges of the two LNBs. Both are on either side of the LNB arm, 97 is flush against it, there is no centre LNB.
14739 30 east water st friendship ny . Thank you so much. Also to throw into your number crunching. I am going to buy a bigger dish. 40 " from impakt for c-band. Didn't know if I should put some of the ku lnbfs on that or not.
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