custom multi lnb for 75e channelmaster

[glover31]

If you look at the setup manual you have in the picture, you will notice that yours has WSNet in the lower right hand corner.

The spot where the Primestar logo would be located can be seen behind other logos on some dishes that was used by other services. Apparently Channel Master used their excess stock to provide them to other companies. But, I have seen some without the logo spot as well, probably re-tooled their molds after the failure of Primestar or they just simply provided them for a reduced price, who knows...

Globecast also used these dishes for their WorldTV service. But I noticed that the feed arm attachment at the bottom was re-tooled on some versions for a different size feed arm. Possibly a later version?

I think SKY used these in the U.K. as well.

There is several different LNB holders originally made for these, but seem very difficult to find now.

For mine I'm hoping to figure out how to make my own, by using electrical conduit and conduit clamps from the hardware store. I remember seeing a post where someone has done that, but I'll have to find it again.

Also thought of trying one of these, but may have to do some modifications to be able to use it: http://www.ebay.com/itm/Multi-Feed-...5-ku-band-LNBs-FTA-5-LNB-Holder-/290908896124

View attachment 111010

i used to have that bracket in the picture. Flimsy. I didn't like it at all.

 

[dsmith0429]

i used to have that bracket in the picture. Flimsy. I didn't like it at all.

That's why I'm going to try and make my own, but use that as a guide... I've noticed quite a few people have simply used electrical conduit and conduit clamps, just have to figure out the best way and place to mount...

Too tied up with work right now, but hope to have a few days soon to work on it...

 

[glover31]

I need to know what my most southern satellite is. I am sitting down doing calculations.

When doing a multi lnbf set up everything becomes reverse. So I am thinking one more of these 1 meter dishes. Set the small dish I have now to 97 west for galaxy 19. One of the one meter dishes to the right and one to the left. The left will pick up the signals from the right and the right dish will pick up the left sats. But I need help finding what the most southern is

 

[catamount]

Your southernmost sat is the same as your longitude. Also, I wouldn't buy any more dishes until you see what the 84E will do. It isn't a one metre. It is .84 metres

 

[glover31]

Your southernmost sat is the same as your longitude. Also, I wouldn't buy any more dishes until you see what the 84E will do. It isn't a one metre. It is .84 metres

78.140 W?
So... C-band would be 78west simon boliver
Ku would be 83west amc 9

That doesn't sound right for some reason. I remember when I did my motorized dish a few years back and it was close to 101 in order to hit all sats. I remember that my most southern sat most different then too but didn't work.

This looks tuff.
the ku sats that look good are 125 103 101 97 95 87 83 72
the cband sats that look good are 103 99 97 95 91 87

SO... I Guess I am thinking of a couple set ups here.
ku cband combo for 87 95 97 103 - the four seperated to two dishes. The remaining 72 83 101 125 ku seperated between the two dishes and maybe a 3rd.

Actually 97 cband might not be worth going after . But I am not even sure what cband would work. I dont know what ones are week or strong.

Also if this 84e dish is not a meter, then that is frustrating as that's how it is advertised.

 

[Titanium]

Curious why you need to calculate your southernmost satellite for a fixed dish install? Aren't you aiming with 97w in the center?

If so, see post #21...

 

[FaT Air]

84e dish is not a meter

It's a meter wide. It will exhibit adjacent rejection = to that of a 'normal' 1 meter dish when aligned with the arc(Skewed) but the gain comparable to a 80 cm dish.
97 & 95 on one dish? Going to have to 'Siamese' two LNBF's for that.

 

[glover31]

Curious why you need to calculate your southernmost satellite for a fixed dish install? Aren't you aiming with 97w in the center?

If so, see post #21...

Great news that you are getting a larger 1m dish! You will have a much better experience.

A Raine and Keith Brannen have provided some great advice and photos. I will just present the similar information slightly different. Between all of our suggestions, you will be successful!

The satellites that you are aiming at are located on the west side of the top of the arc from your location. Your due south satellite is approximately 78w. This means that the LNBFs installed on the West side of the centered 97w LNBF will be lower and the LNBFs on the East side of the centered LNBF will be higher. For the initial aiming, I would keep the dish skew at default level position and adjust the height for each position. You might want to optimize the dish gain be calculating the reflector skew setting at a future time, but for now, it just adds another variable to the LNBF positioning and will make the aiming more difficult. If you wish to continue and try to set the reflector skew, I do not have a way of calculating the reflector skew setting for your reflector. You might try the setting recommended for a DirecTV install for your zip code. Not sure if the setting will remain accurate past the +/-9 satellite offsets that DirecTV uses.

Here are 3 satellites for aiming based on your zip code 14739:
87w Elevation 40.4, skew +9.5
97w Elevation 37.5 skew +19.5
103w Elevation 35.1, skew +25

• With 97w satellite in the center LNBF position, set the dish elevation to approximately 37.5 degrees. Connect directly to the LNBF and tune the STB to 97w and place on an active transponder. Rotate the LNBF skew to approx. +19.5. Aim/optimize the dish. Blind Scan for channels.
  
• Connect directly to a second LNBF and tune the STB to 87w and place on an active transponder. Rotate the LNBF to +9.5 degrees skew and hold on the West side of the centered LNBF. Slightly lower the LNBF and move slowly left/right while watching the Signal Quality meter. Once the Signal Quality reading is registered, take note of the approximate location and set the clamp to hold the LNBF. Once the clamp is in position, fine tune the LNBF position to optimize the Signal Quality. Blind Scan for channels.
  
• Connect directly to a third LNBF and tune the STB to 103w and place on an active transponder. Rotate the LNBF to +25 degrees skew and hold on the East side of the centered LNBF. Slightly raise the LNBF and move slowly left/right while watching the Signal Quality meter. Once the Signal Quality reading is registered, take note of the approximate location and set the clamp to hold the LNBF. Once the clamp is in position, fine tune the LNBF position to optimize the Signal Quality. Blind Scan for channels.
• Power OFF STB. Install switch. Power on STB. Program the switch setting port for each satellite.

Well... Based on the negative experience of attempting to get more than one sat on the current dish. e74, It is obvious that the e84 is only going to be a little better. I figured I would get several to come in but that one dish being the e84 wasn't going to pull them all in. At least not reliably. I figured It would be easier to use at least two dish's and then the one I already have as a 3rd for a sat that is harder to pull in with just one lnbf designated to that dish. Maybe two. But incorporating cband into the whole project.

Now the reason I need to calculate my southernmost satellite for a fixed dish install "I think" is because, "firstly" If my most southern was center of the arc, then I could set a dish on an angle in this order. Center most southern sat and furthest on the outsides of the dish. So lnbf's furthest apart and dish skewed for both sats to be tuned in. Then all the sats in-between should be easy to tune in when placing extra lnbf's in between the first two.
The same for a second dish. Only using the second most southern sat and then the furthest on the other end of the arc skewing the dish to hit both sats. Then adding additional lnbfs in between.

I think also that the sats will be in opposite places. So the right dish would be for left sats and right dish for left.


I am trying to get away from having to make an odd ball apparatus for each lnbf. This is why I asked about using the direct sat brackets. they are 9 degrees apart and 10 at one end. There is a spot to drill for in between. That would make things 4.5 apart and 5 degrees twice at one end. Not sure what I could do with that. But certainly sounds like the right direction. Mount lnbf single holders to each hole.
My understanding is for ku, that one can essentially take 3 2.4 dishes and pick up everything on the arc. Hell of a lot of lnbf/s.

 

[glover31]

It's a meter wide. It will exhibit adjacent rejection = to that of a 'normal' 1 meter dish when aligned with the arc(Skewed) but the gain comparable to a 80 cm dish.
97 & 95 on one dish? Going to have to 'Siamese' two LNBF's for that.

3 to 4 lnbf's. I hope

 

[Titanium]

Sorry, but I think that this approach to the multi-satellite project is going to bring you a lot of frustration. Skewing the dish and having preset feedhorn distances may work fine for high power DSS satellite reception using circular polarity, but not so easy with lower power linear polarity FSS satellites. If you set the skew angle for the satellite positioned in the middle of the group that you are attempting to receive, then the individual LNBF adjustments will be minimized. The signals from the multiple satellites will be optimized by placing each LNBF at the correct height and skew. It will be very difficult if not impossible to set one skew or elevation and have optimized Signal Quality set for each satellite.

This printout may be helpful for you to visualize the arc, elevations and LNBF setting:
http://geosatfinder.com/Reports/Sat...5,213,211,210,200,182,209,181,189,190,247,227

 

[glover31]

Sorry, but I think that this approach to the multi-satellite project is going to bring you a lot of frustration. Skewing the dish and having preset feedhorn distances may work fine for high power DSS satellite reception using circular polarity, but not so easy with lower power linear polarity FSS satellites. If you set the skew angle for the satellite positioned in the middle of the group that you are attempting to receive, then the individual LNBF adjustments will be minimized. The signals from the multiple satellites will be optimized by placing each LNBF at the correct height and skew. It will be very difficult if not impossible to set one skew or elevation and have optimized Signal Quality set for each satellite.

This printout may be helpful for you to visualize the arc, elevations and LNBF setting:
http://geosatfinder.com/Reports/Sat...5,213,211,210,200,182,209,181,189,190,247,227

Thanks. And just for my saving so I don't stress myself for no reason, what is the most anyone has done on this dish so I am not trying to do more than most have already accomplished. I don't want to reinvent the wheel here. Pictures would be so great

 

[Titanium]

A few years ago on a 90cm, I had done 4 FSS linear and one DSS circular off to the side (when a few Dish channels were in the clear).

 

[glover31]

A few years ago on a 90cm, I had done 4 FSS linear and one DSS circular off to the side (when a few Dish channels were in the clear).

Ok. So then the 4 fss and the one dss all looked the same as a dtv lnbf? Did you mount them in a dtv lnbf holder?

 

[Titanium]

My set-up looked similar to A Raine's photo in post #18. I made the LNBF riser clamps from pipe hangers and all thread. Similar to RimaNTSS gorgeous works of art, but with much less art! LOL!!! http://www.satelliteguys.us/xen/posts/3755441/

 

[glover31]

My set-up looked similar to A Raine's photo in post #18. I made the LNBF riser clamps from pipe hangers and all thread. Similar to RimaNTSS gorgeous works of art, but with much less art! LOL!!! http://www.satelliteguys.us/xen/posts/3755441/

Am I going to have any issue using cpvc connected directly to the arm. Like, measure the cpvc to width of dish, find center. Drill a hole. Buy a bolt washers and nut. Assemble then use my already built lnbf's?

 

[Titanium]

The offset LNBF mounts need to be able to be fine tuned up/down/left right in order to track the arc and be aligned with each satellite. Remember, the satellites are not in a straight line across the horizon. Highest at the true South satellite and the arc falls off to the East and West horizons.

Moving the feedhorn opening even a 1/4" up/down/left right will make the difference between locking a channel with an excellent signal Quality reading and having no Signal Quality.

 

[glover31]

The offset LNBF mounts need to be able to be fine tuned up/down/left right in order to track the arc and be aligned with each satellite. Remember, the satellites are not in a straight line across the horizon. Highest at the true South satellite and the arc falls off to the East and West horizons.

Moving the feedhorn opening even a 1/4" up/down/left right will make the difference between locking a channel with an excellent signal Quality reading and having no Signal Quality.

What are your thoughts on this?

 

[FaT Air]

You have to 'mimic' the LNBF placement of the holder in your hand in the 4th picture. As you've done I think they are too close to the dish and the angle is off.

 

[RimaNTSS]

What are your thoughts on this?

There is no central LNB, which should be placed in such a way that its Focal point co-located with antennas Focal point. Secondly , in your construction there is no possibility to adjust height of LNBs.
Do you know where is Focal point of this antenna?

 

[glover31]

You have to 'mimic' the LNBF placement of the holder in your hand in the 4th picture. As you've done I think they are too close to the dish and the angle is off.

There is no central LNB, which should be placed in such a way that its Focal point co-located with antennas Focal point. Secondly , in your construction there is no possibility to adjust height of LNBs.
Do you know where is Focal point of this antenna?

I dont know. I do not like the arm that came with the dish. Its more of an arm that would come with direct tv kind of dish. I measured it and it is not as long as the one that would go to the 74 e star band dish. SEE PICTURE again. It also doesnt have the same angle for the lnb with the included bracked that the 74 e would have. The only difference between these dishes is size. So I dont think the arm should change that much. If I was to use the included arm and bracket I am thinking that YES the angle and focal point will be off. No I dont have a way to adjust lnbf up and down yet. I think you could be right though. I think the lnbf are indeed to close.

I will take some side pictures when I get home. That way everyone will get a better Idea. Maybe I will take some measurements to.