Winegard 76cm focal point

[Vorg]

Does anyone have this information for the Winegard 76cm (31") ? I found a thread that had the focal point distance to center of mounting bolts and to the top and bottom edge of the dish, but it was for the 1m dish. Ether my arm is really bent (dosn't look it) or I'm missreading the specs.

Information I have is:
Effective Aperture 76 cm / 31 "
Antenna Height 87 cm / 34.3 "
Antenna Width 80 cm / 31.5 "
Antenna Weight 4.18 Kg. / 9.8 lbs.
F/D .59
Offset Angle 24 degrees
Focal Distance 44.6 cm / 17.56 "

There are 2 adjustment option, the holder moves in/out at an angle so it also moves up/down. And the LNB of corse can be moved a little. I am using this with a Invacom CP/LP and sg2100. My first try I had both all the way in and got from about 79w to 123w, but it was marginal and I have clear view. I am at 110.89, 32.23 and from what Im told I sould be able to get more.

I had a problem with the motor clamp crushing the pipe partly because the streght section after the bend was too short I replaced the pipe with a section of fence post cut and welded with 2 joints at about 22 degrees to get the 45 the original had which puts the weight over the roof mount. I spent a good 30 minutes with 2 angle finders making sure the new post was vertical. After mounting the motor I set the shaft as close to 62 degrees (32 plus the 30 bend in the shaft) as I could get it again using both angle finders as there is a very slight difference between them.

I was told by someone on another board that it should be 17.5 from the bottom edge of the dish to the front of the LNB which is possible setting everything back. But with that setting I could only get to about 93w LP after setting to 110w CP and that was marginal. Decided to try going the otherway from 110 and seemed to eb able to fine tune the az on 116.8. Was late and thought I had it, so went down, reconnected to my VDR (used a Neusat 6000 on the roof for alignments), and found all I could lock was 116.8 and 110. If the motor elevation is suposed to be 32 degrees then arc curve should be right. So Im assuning its the dish focal point. I read here and am now told by others that its to the center of the dish bolts. The range I have to center is 19.5" - 20.75". That's a bit far from the 17.56" listed to just be a bent arm.

 

[Larry1]

I do not have the specs for the 76cm dish, but did get the specs for the 1m dish directly from Winegard just by requesting them. They faxed me the drawings that are in the scan. Try emailing them asking for the drawings for you can adjust the feed arm to the proper position. (if they do send them, please post them here as well)

 

[Vorg]

ok, thanks. I looked around their web site. Too bad they don't just post that data. Not like it's a trade seacret

 

[mastermesh]

I've got a similar setup

and soon will be ordering a new motor cuz mine just fizzled on me a few weeks ago.. Anyways, how are you holding the lnb up? One thing I noticed when I was setting mine up was that the invacom tended to be a little on the heavy side for the lnb holder... so I had to make do with wire ties to hold the lnb head down, and some wadded up duct tape between the lnb arm and the lnb base to hold the lnb base white part back so that it's at a good angle out from the arm... it tends to move a bit in the holder, so you have to get a good signal and find some way to hold it there. Do some fine tuning while on G10, looking at both strong and weak signals.

 

[Vorg]

Cox mail went down, so don't know if winegard's responce will get lost in the mail or what. mail been down all day. I run all email through my domain which then forwards to real email and I just switched forwading to backup. but looks like most of the days mail is already stuck in cox severs.

With the plastic holder all the way forward, I didn't notice that it was that floppy. Was a little but not bad. With it full back and the lnb fully back it does move a bit for my liking. I was more concerned with the whole arm. It was moving too easy so I added 2 support alum suport rods. They are bent 90 degrees and threaded at one end, then feed through the lower holes on each side of the dish flange. At the end I took a scrap of L alum and driled 2 holes for the plastic holder screws to go on through. Also driled 2 holes for the other end of the rods, bent the rods about 15 degrees and threaded those ends. Makes the over all arm a lot strong. But if the arm is this far off, ill have to rework those rods a bit.

 

[GaryPen]

Does anyone have this information for the Winegard 76cm (31") ? I found a thread that had the focal point distance to center of mounting bolts and to the top and bottom edge of the dish, but it was for the 1m dish. Ether my arm is really bent (dosn't look it) or I'm missreading the specs.

Information I have is:
Effective Aperture 76 cm / 31 "
Antenna Height 87 cm / 34.3 "
Antenna Width 80 cm / 31.5 "
Antenna Weight 4.18 Kg. / 9.8 lbs.
F/D .59
Offset Angle 24 degrees
Focal Distance 44.6 cm / 17.56 "

There are 2 adjustment option, the holder moves in/out at an angle so it also moves up/down. And the LNB of corse can be moved a little. I am using this with a Invacom CP/LP and sg2100. My first try I had both all the way in and got from about 79w to 123w, but it was marginal and I have clear view. I am at 110.89, 32.23 and from what Im told I sould be able to get more.

I am assembling my dish and lnb now. I am not sure how to set the lnb distance adjustment.

Judging from the above information, do I set the distance from the center of the dish to the face of the LNB at 17.56"?

Also, since I am using a motor, do I set the skew at 0?

 

[Vorg]

I am assembling my dish and lnb now. I am not sure how to set the lnb distance adjustment.

Judging from the above information, do I set the distance from the center of the dish to the face of the LNB at 17.56"?

Also, since I am using a motor, do I set the skew at 0?

The distance thing is what I am trying to confirm. It is my understanding that if you draw an X between the 4 bolts that mount the dish, the center of the X is the center of the dish you mesure from. You should have 17.56" (we think) from that point on the dish to just inside the front of the LNB. The focal point should be on the other side of the plastic cover. You can fine tune by sliding lnb in and out while watching signal strength and quality. You want both as high as you can get it with priority going to quality. I'll post here when/if I hear from Winegard. My email is working again and Cox claims no mail was lost.But it will take up to 24 hours to get all the held mail delivered.

As for skew, Skew is always 0 for motor setups. As the dish sweeps the sky, the skey changes with the dish angle. So just set it to 0 degrees.

 

[mastermesh]

I pushed my lnb back as far as it would go, which explains why it's a little flimsy at the moment and needs the extra support. I don't know if that's the way that it's suppossed to be or not, but when I was fine tuning a few weeks back it seemed to be the way that was making the signal just a smidge stronger. I'll have to redo everything an a few weeks since I just ordered a new sg2100 last night to replace the cruddy one that no longer works. I was going to send in the bad one for fixing at dmsi, but some guy at dmsi in another thread showed me their ra form - cost of repair he claims, is 25.00 an hour + parts + shipping, but somewhere on their site I saw something that mentioned 45.00 and hour. He claimed they could fix it in under an hour, but who knows if it'd be that fast... 3 hours and that's at least 75.00

When sg2100s can be had at ebay for right around 60.00 with shipping, and at Sadoun for 75.00 + 12.00 shipping, I figure it's probably better to get a new one. I went with ebay because that ends up being about 25.00 cheaper than Sadoun. I trust the guy I bought it from on ebay since it's the same dude I bought the winegard from in the first place, goes by FTANOW on ebay I think.

 

[Vorg]

Got the pdf from winegard and it seems they do it different for the 76cm dish. It IS from the bottom edge of the dish to the lnb. And 30.534" from the top edge to the lnb. So guess I have another problem then. I'm wondering if the Neusat USALs are off, at least when dealing with the 116.8 sat. Because that was the last one I alined to and it took out all the other LP sats.

I've also heard that for some, the elevation turned out to be about 5 degrees off from what was calculated. I have checked several including one that used sat photos which let me click on the section of my roof that it is mounted to. Using the angle finders on the motor shaft put the motor on the stamped marks the book said for this area. So it seems it shouldn't be that far off. I figure less then 40' cable to receiver and was only use about 5 on the roof during alignment.

Ok, stupid misstake, When I was going from the bottom edge of the dish to the bottom edge of the lnb insted of center of lnb. For my dish, it looks like it will require the lnb forward. not sure where the plastic clamp will end up. going to just make a cardboard templete and work from there.

 

[LordAlex]

Thanks for posting that pdf. I'll definitely measure mine this weekend!

 

[GaryPen]

Thanks Vorg! One more thing for me to check when I get home.

 

[mastermesh]

Foward ya say? I may have to get that fixed next go round when my new motor gets here. Ain't it fun going up on the roof all the time to fiddle with this stuff. Feel like I may need to put some more reinforcements up there and get a tap dance stage.