Question on lnb

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cruzin

SatelliteGuys Pro
Original poster
Apr 13, 2009
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michigan
Hello, I have a couple questions. I am going to help someone get into fta. I am giving them a 39" directway satellite internet dish. My questions are to make it usable for fta can one leave the transmit/receive lnbs in place and use them? Or should one remove the big rectangular arm that they are mounted on leaving the 2 side arms and make a new lower tube arm. AND
In measuring the focal depth for this dishes lnbs feedhorn does the measurement start at the cover of the feedhorn that keeps bugs out or back somewhere else? It has a great big feedhorn on it and if we remove all the lower arm I need to know how long to make that lower are and place the lnb. thanks for any information.
 
Hello, I have a couple questions. I am going to help someone get into fta. I am giving them a 39" directway satellite internet dish. My questions are to make it usable for fta can one leave the transmit/receive lnbs in place and use them? Or should one remove the big rectangular arm that they are mounted on leaving the 2 side arms and make a new lower tube arm. AND
In measuring the focal depth for this dishes lnbs feedhorn does the measurement start at the cover of the feedhorn that keeps bugs out or back somewhere else? It has a great big feedhorn on it and if we remove all the lower arm I need to know how long to make that lower are and place the lnb. thanks for any information.

I've successfully used an old DW dish for FTA with very little to no mod required. The LNB is linear - but I did take the TX box off just to reduce weight (see my avitar).

These dishes give a surprisingly good FTA signal with little to no mods needed.

As a note - if you take the TX box off there will be a hole left for water intrusion. I plugged the hole with a piece of plastic & liquid nails to make it water tight. Used it for a few monthe before I moved on with NO probmems.

Great primer dish for FTA.
 
thanks for the reply. do you happen to know where to measure for the focal depth? at the beginning of the feedhorn cover or back on feedhorn or where feedhorn bolts to transmit lnb? thanks
I've successfully used an old DW dish for FTA with very little to no mod required. The LNB is linear - but I did take the TX box off just to reduce weight (see my avitar).

These dishes give a surprisingly good FTA signal with little to no mods needed.

As a note - if you take the TX box off there will be a hole left for water intrusion. I plugged the hole with a piece of plastic & liquid nails to make it water tight. Used it for a few monthe before I moved on with NO probmems.

Great primer dish for FTA.
 
I'd leave the transmitter thing on there if you're going to have to do some modifications after taking it off. It'll work just fine for fta with it on there, and it won't be able to transmit anything like that. The direcway dish I have only has the one lnb support on it, the transmitting stuff was on it, about halfway from the dish, like Baja I took mine off too, but you really don't have to, to use it for tv.
 
Thanks for reply, you probably took some measurements before you took it off. Where did you measure from to set the next lnb? He may want to go with a motor so I think its best to get rid of the bottom support arm and put a light weight tubing arm instead. My question is: from what point on the big feedhorn do you take the measurement from for the new lnb focal depth. thanks again
I'd leave the transmitter thing on there if you're going to have to do some modifications after taking it off. It'll work just fine for fta with it on there, and it won't be able to transmit anything like that. The direcway dish I have only has the one lnb support on it, the transmitting stuff was on it, about halfway from the dish, like Baja I took mine off too, but you really don't have to, to use it for tv.
 
Maybe your DirecWay dish is different, but mine doesn't have side support arms.
Just a lower LNB support tube.
And, to reduce the weight to motorize it, I'd take off all that heavy mount hardware behind the dish!
Leave the LNB support alone; it's fine.

Show us a picture of what 'cha got, please. -
 
Mine must be different type of lnb holder arm. The dish is a round 39 inch dish. with a large heavy channel arm on the bottom holding the transmit portion and the receive lnb is on the side with a angle 90deg holder going into the transmit feedhorn. I just thought if he wanted to motorize it would be better to get rid of the weight of that large bottom arm. If he could find out where to measure from what part of the feedhorn.
I know I have read somewhere where you start the measurement from the feedhorn to setup focal depth at but can not find it again. Unless he could find a adapter for the feedhorn as the transmit part has about 10 allen bolts holding it to the feedhorn and the receive lnb only has 4 allan bolts holding it on.
Maybe your DirecWay dish is different, but mine doesn't have side support arms.
Just a lower LNB support tube.
And, to reduce the weight to motorize it, I'd take off all that heavy mount hardware behind the dish!
Leave the LNB support alone; it's fine.

Show us a picture of what 'cha got, please. -
 
This is the only 39" round DirecWay dish I've ever heard of.
MexSunny has one in Mexico. Does yours look like this?

Mostly, when we say DirecWay or DirecPC dish in the USA, we mean an elliptical dish.
Here is mine, DirecWay 39x23 http://www.satelliteguys.us/attachment.php?attachmentid=32233&d=1229832892
Here is similar model from another thread: http://www.satelliteguys.us/free-ai...ng-info-direcway-dw4000-dish.html#post1460009

The dish looks like that but the transmit and receive set up is a bit different. see pictures. sorry for poor quality of pictures as night was coming on. I had removed mount and arms so I could get it down from the rafters in my pole barn. Your type dish would be alot easier for using for fta. The lnb arm and transmit section is quite heavy and the mount weighs in very heavy. dish is fairly light. good candidate for motor
 

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I do not think so, I took the dish and all down to a friends house so I can not go check. On my question on where you start measuring for focal depth I was wanting to know where you measure the f/d from. The beginning of the feedhorn cover or back where the lnb is bolted to the feedhorn. I measured my 1.2 dishes I have pictures posted of and both of my focal depths are different. The one with store bought lnbs is 31 1/2 from deepest part of dish and the commercial lnb that came with the muzak dish (both dishes identical) is 32 1/2 at the beginning of the feed horn and 35" back where the lnb bolts to the feedhorn. So the feedhorn is 2 1/2 " long.
I found a formula for f/d and I will see what it tells me if I can do the math proper. Been a long time since school. BOth of my dishes are 48 1/4 wide at widest part and 52 1/2 tall. and I laid a 6 ft flat bar top to bottom in the middle and found just over 4 9/16 deep at the deepest part of dish which looks like where the commercial lnb points to.
Ok, I found a web site that will figure f/d so I plugged in all my equations and it looks like you start your measurement at the front of the feedhorn. question solved. I am 1/10 of a inch off in my placement of the lnb using the commercial lnb. the store bought ones are a different breed and must be you have to guess at them!
is there 2 cables coming out of that LNB?
 
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Here's how to find the existing focal point.
If you use the dish and not the LNB arm as your reference point, you should be able to construct a template that'll let you locate a new LNB feed at the correct spot.

Let's see that dish from the back side.
It's got molded-in ribs, doesn't it?
I think many of us would be very happy to make custom LNB arms for such a nice commercial dish, if we had one.
If you have a surplus of 'em, do share with your neighbors! - :up

We've had threads in the past, on converting similar dishes by removing the heavy mount, then sticking 'em on way-too-small SG2100 motors. :)
So, I have no doubt you can do as well or better! :cool:



How to locate a new LNB at the proper focus, when replacing it:
http://www.satelliteguys.us/free-ai...ert-superdish-true-fta-use-2.html#post1540313
 
Id like to have so many I could give one to everybody who wanted one. I have given 2 1.2m and 1 1m dishes away and helped them set up on a fta sat. . I'll have a look at the link to the f/d help and also pass it on to the friend I gave this 1 meter dish away to. thanks
 
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