jerryt said:
The main reason some of us are staying away from the 6 footer is you cannot mount that on a motor (like the 4 footer can)
120cm dish with C-Band performance - Now with HD!
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The main reason some of us are staying away from the 6 footer is you cannot mount that on a motor (like the 4 footer can)
Yes, a 6 foot prime focus on a HH mount motor, with Ku and C Band.
Now where do I find the mount for Sadoun's 6 foot prime focus?
Now where do I find the mount for Sadoun's 6 foot prime focus?
A quick FYI:
My SG2100 packed up on me this evening while scanning for T5 on C-Band, all the movement on this C-Band project finally took its toll and it's stuck at 0.
I'm not blaming the positioner, it's served me well, I just don't think motors are designed for this type of abuse especially over the last month or two with all the movement and weight of the 120cm dish.
For now my participation is on hold unless I decide to mount the dish in a fixed position or find another positioner.
http://www.satelliteguys.us/showthread.php?t=74660
My SG2100 packed up on me this evening while scanning for T5 on C-Band, all the movement on this C-Band project finally took its toll and it's stuck at 0.
I'm not blaming the positioner, it's served me well, I just don't think motors are designed for this type of abuse especially over the last month or two with all the movement and weight of the 120cm dish.
For now my participation is on hold unless I decide to mount the dish in a fixed position or find another positioner.
http://www.satelliteguys.us/showthread.php?t=74660
Been reading with great interest. Using 2700, ASC 421, 170cm Winegard. Some comments about focal point, Ku was at 66cm, ASC 421 @ 64.25. The chat about the cone shaped scaler took me to my lathe, found an old scaler, cut the rings out just right, turned it into a cone. I went to Anik F1, started with bare lnb, qual. 45%. Then I put on the flat scaler, worked best for me with lnb extending beyond rings about 3/4" , qual. 74-85%. Then tried cone shaped scaler, the best it did for me was about 60%, tried several settings. The dish I found is light, doesnt seem to overload the motor any more than the steel dish I had. I was interested in the lnb settings you guys were using for the ASC 421, single works well, but try scanning G 10R using Universal 1 setting, I found some new things !! Go to edit TP/Sat , NEW, name it G 10 U !
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Alec, fantastic work on the scalar - that's exactly what I was planning to do with my scalar ring, I don't have a lathe and a Dremel isn't precise enough.
The cone-shaped scalar is more for an offset dish, if you feel like knocking a few more out I'm sure you'd have some customers.
The cone-shaped scalar is more for an offset dish, if you feel like knocking a few more out I'm sure you'd have some customers.
Alec brings up a point I wondered about. It seems as though the following facts are true:
1. SG2100's are rated for about 10kg.
2. Fortec 120cm dishes weigh about 17kg.
3. Wire mesh dishes are much lighter than pressed steel dishes.
4. Wire mesh dishes seem to all be prime focus, not offset.
5. Wire mesh dishes are sometimes cheaper, or at least much cheaper to ship, than 120cm dishes.
All this makes me think... if somone made an offset wire mesh dish, modified the mounting, and attatched it onto an SG2100, you'd get a rather large dish with Diseqc capability that wouldn't kill the motor- and also probably get much better C-Band reception, seeing as it would be larger than 120cm.
I know this isn't the norm, but what about this thread is?
Just a thought I'm curious about. If well-made 1.2m steel dishes kill motors, and lousy tinfoil dishes... well, are lousy and tinfoil then wouldn't a happy medium be a large but mesh dish?
1. SG2100's are rated for about 10kg.
2. Fortec 120cm dishes weigh about 17kg.
3. Wire mesh dishes are much lighter than pressed steel dishes.
4. Wire mesh dishes seem to all be prime focus, not offset.
5. Wire mesh dishes are sometimes cheaper, or at least much cheaper to ship, than 120cm dishes.
All this makes me think... if somone made an offset wire mesh dish, modified the mounting, and attatched it onto an SG2100, you'd get a rather large dish with Diseqc capability that wouldn't kill the motor- and also probably get much better C-Band reception, seeing as it would be larger than 120cm.
I know this isn't the norm, but what about this thread is?
Just a thought I'm curious about. If well-made 1.2m steel dishes kill motors, and lousy tinfoil dishes... well, are lousy and tinfoil then wouldn't a happy medium be a large but mesh dish?Cascade, thanks. The end result of the cone mod, didnt seem to justify the effort. Up close it doesnt look to pretty.....LOL. I felt I had to do it, the couriosity was driving me nuts !! Say.......that ASC 421 is one heck of a versital unit !!! Feel free to check it out fully ! Oh, I found the toothpaste channel on Anik......LOL
Don't throw it away! I know someone will give it a good home if you don't want it
That toothpaste channel scares me, what's the deal with that one?
CharredPC - back in the motherland most of the dishes for Sky (UKs DirecTV) were mesh, you can still buy the 80cm mesh dishes some places.
That toothpaste channel scares me, what's the deal with that one?
CharredPC - back in the motherland most of the dishes for Sky (UKs DirecTV) were mesh, you can still buy the 80cm mesh dishes some places.
My falsies will last me a lifetime (j/k)
The good news is that my motor should be back up and running soon
(j/k)The good news is that my motor should be back up and running soon
I installed my Patriot 1.2 meter dish today. It went together without much "blue" language and I did it myself without help. It is pointed at Anik F1 right now and am receiving all available channels with 70-79% quality! Channels that were not available with the P* are now booming in with the monster dish. Currently using it with the ASC421 as the offset LNB wont arrive until Wednesday. Will be ordering an HH120 as I really need to motorize this baby.
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Wow, the quality of that dish looks fantastic, the rolled edges will help with stability, nice pics too.
Where in Chesterfield are you? I may have to pay a visit in the early hours.
Now where did I put that wrench.....
Where in Chesterfield are you? I may have to pay a visit in the early hours.
Now where did I put that wrench.....
Ive never seen the inside of Ku lnb's , popped some open. They have a very distinct funels to them. The one on the left is circular, mid is linier, left is my mod. The funel mod Id made from a flat one, I dont believe is deep enough, nor proper length of interior rings. I still have some flat ones left, will fire up the lathe again, try for a more efficient cone. This cone thing is stuck in my head.
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"Then I put on the flat scaler, worked best for me with lnb extending beyond rings about 3/4" , qual. 74-85%. Then tried cone shaped scaler, the best it did for me was about 60%, tried several settings."
That's because your dish (or at least the one in the photo you attached) seems to be a prime focus dish. For a prime focus dish this is probably the way the scaler ring should be. Your modifed scaler ring would likely work better on an offset dish like others in this thread are using. Anyway, the F/D ratio of a dish is the main factor in the shape and placement of the scaler ring. So, the thing for you to do is first measure this for your dish by measuring the distance to your focal point and dividing it by the diameter of your dish. Then if the feedhorn allows for it set the scaler ring to the marking on the feedhorn that corresponds with your F/d ratio. For a prime focus dish the feedhorn will probably allow for this in it's unmodifed condition as the feedhorn is probably desgined to accomadate F/D ratios for prime focus dishes. Offset dishes, like the ones others are using in this thread have a much higher F/D ratio. Thus the need for a "cone" shaped scaler ring to extend the rings farther out from the mouth of the feedhorn. This is because offset dishes are kind of like half of a dish (or the upper half of the parabola). This means the F/D ratio of most offset dishes is roughly about twice that of most prime focus dishes. So, your modifed ring would probably work best on an offset dish and not your prime focus dish.
Some of the documents on this page have some really good info on feedhorn design. You might want to read through some of them before doing any more machining to your feedhorn and scaler ring.
http://wireless.ictp.trieste.it/school_2003/docs/radio/microwaveantennabook/Files/
That's because your dish (or at least the one in the photo you attached) seems to be a prime focus dish. For a prime focus dish this is probably the way the scaler ring should be. Your modifed scaler ring would likely work better on an offset dish like others in this thread are using. Anyway, the F/D ratio of a dish is the main factor in the shape and placement of the scaler ring. So, the thing for you to do is first measure this for your dish by measuring the distance to your focal point and dividing it by the diameter of your dish. Then if the feedhorn allows for it set the scaler ring to the marking on the feedhorn that corresponds with your F/d ratio. For a prime focus dish the feedhorn will probably allow for this in it's unmodifed condition as the feedhorn is probably desgined to accomadate F/D ratios for prime focus dishes. Offset dishes, like the ones others are using in this thread have a much higher F/D ratio. Thus the need for a "cone" shaped scaler ring to extend the rings farther out from the mouth of the feedhorn. This is because offset dishes are kind of like half of a dish (or the upper half of the parabola). This means the F/D ratio of most offset dishes is roughly about twice that of most prime focus dishes. So, your modifed ring would probably work best on an offset dish and not your prime focus dish.
Some of the documents on this page have some really good info on feedhorn design. You might want to read through some of them before doing any more machining to your feedhorn and scaler ring.
http://wireless.ictp.trieste.it/school_2003/docs/radio/microwaveantennabook/Files/
Stefan, thanks for link. I made new cone before finding your post. Id gone back to the lathe this morn. built new cone. I agree now that I dont have the right dish to be doing field trials with this new cone. Cascade has contacted me and I will send the new cone to him for field trials. It took 3 flat scalers to build parts in order to maintain ring depth, new cone is deeper. In a week or so, Cascade will be able to check this cone out. Thanks
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Cascade said:
Cascade,
Why don't you make up a quick horn antenna and stick that on instead of the scalar ring and see what that does?
My motor is out of action right now, I should have a working system back in the next few days - I may give the horn idea a go if I can find the materials.
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