Which c/ku-band feedhorn is best?

[wen]

These are two of my old feedhorns that haven't been used in 19 years. They both seem to be in good shape and both made by Chaparral. The first one has the Ku LNB centered on the dish and the c-band LNB on the Polar Axis 3 inches from centered. It uses two polarators. This one is not shown on the Chaparral website. The second one is the Chaparral Corotor II plus and uses a single polarator. (not the wideband version). The c-band is 25 degrees and the Ku band is 0.7db noise figure. This will replace a BSC621-2D LNBF. Any suggestions which is better before I start mounting them on the dish?

 

[primestar31]

The center-fired one for both bands is "better" of the two choices, if you want both bands on a single dish that is. That's why Chaparral no longer sells the other one with off-set feeds.

 

[Hockeynut]

Corotor II without a doubt as primestar stated.

 

[anik]

I'm curious - if you don't mind saying, why are you replacing the BSC621-2D with the older technology? Reason I ask is because I was thinking about doing just the opposite of what you're doing later this year, and the BSC621-2D was actually the one I was leaning toward. Is there some problem with it, or are you just wanting to experiment with the older stuff, or what?

 

[Titanium]

LNBFs are a compromise of performance for convenience. A mechanical polarizer (Corotor) provides superior performance and ability for optimization over a LNBF. This optimization is especially critical on high FEC S2 signals 7/8, 8/9, etc. where even the slightest signal error will degrade the signal and it is unable to be decoded. Easy to pick-up 10 - 20% BER when or on a transponder with adjacent satellite interference or terrestrial interference and rolling off the skew. In the analog days the skew fine-tuning would reduce sparklies. Today it helps avoid the digital cliff.

 

[anik]

Excuse me, Titanium, but I wasn't asking you - I was asking wen (the OP). Since you are trying to sell your expensive positioner controller (that can control a polorotor) at four to five times the price of the competing model (that can't), I would be inclined to think that anything you have to say on the subject just might be colored by a commercial interest. I specifically asked here because I wanted the opinion of someone who is not in the business of selling controllers.

Since you butted in, maybe I should accuse you of being a troll now, like you did to me in that other thread.

 

[shopman]

Anik, Titanium's response was informative in regard to the benefit of using a corotor-type feed as opposed to an LNBF, which is always a compromise. Perhaps I'm blind, but I didn't see any reference made to the ASC1. I'd say your comments were uncalled for. Food for thought.

 

[Magic Static]

I'm sure Titanium won't make the same mistake again. And I also will learn from that mistake.

 

[Titanium]

Wow! Where did that zinger come from? LOL!!!

Sorry, I will try to be less informative and helpful when a question is asked in an open forum....

 

[eurosport]

Excuse me, Titanium, but I wasn't asking you - I was asking wen (the OP). Since you are trying to sell your expensive positioner controller (that can control a polorotor) at four to five times the price of the competing model (that can't), I would be inclined to think that anything you have to say on the subject just might be colored by a commercial interest. I specifically asked here because I wanted the opinion of someone who is not in the business of selling controllers.

Since you butted in, maybe I should accuse you of being a troll now, like you did to me in that other thread.

anik, please refrain from such responses, as it can be considered flaming a member, which could result in an infraction if it continues. Thank you.

 

[Mr Tony]

Since you butted in, maybe I should accuse you of being a troll now, like you did to me in that other thread.

so him giving a legit technical reason why the older C/KU feedhorn in alot of cases is better than the newer LNBF's is trolling? Thats a new one
Would it have been OK if I copy/pasted Brian's post?
(after all I have no commercial interest)

 

[Lone Gunman]

Since I have first hand experience with the swap he was asking about, I sent him a PM with info he was asking for, ie, I have a Corotor II with C/Ku Norsat LNBs laying the bench in my shop and an LNBF mounted on the dish.

 

[richyrich]

Wow! Where did that zinger come from? LOL!!!

Sorry, I will try to be less informative and helpful when a question is asked in an open forum....

My design works both in dual c band dual ku multi satellite and everything in between. All old feeds work the same as all new feeds work, and the old ones shown on this thread can work too; using manual labor per channel for polarity and only 18v in the receivers menu per transponder. Many old receivers will even change the manually driven polarity control. The ideal satellite receiver receives One Channel at a time, as they ALL DO; these old feeds can be arrayed on a BUD for multi-satellite reception; one or more channels from each polarity received and never need to be polarised again, if desired. The c ku at offset will pick up 2 different satellites at the same time! If you have only one satellite dish too! Each can be also arrayed on a moving BUD too, and with any other type like the newer ones are c ku too. And when arrayed with LNBf switched designs can all work with every receiver ever made. Look at your local cable company; they array them all!

 

[wen]

Wow!

Where did that zinger come from? LOL!!!

Sorry, I will try to be less informative and helpful when a question is asked in an open forum....

Please don't. I always appreciate all points of view and we got a lot of points of view in this thread.


Same goes for MagicStatic and all the other people who responded to this thread.

Here is a picture of my first LNA, which was home-made in 1980. At that time the tiny semiconductor devices went for over $1000 each! Note that the probe and waveguide were solid copper with a brass waveguide flange. It worked quite well, but no match for the 25 degree LNB's that were just a few hundred dollars in 1990. Quality LNB's are still in the $120 range for a 15 degree LNB. These have accurate, detailed, and repeatable specifications of what you are paying your money for.


I am sure I will get better and much more consistent performance from the Norsat LNB's and Chaparral Feed-horn's. My BSC621-2D LNBF was not quite as good as my DMS BSC421 on c-band and on Ku, the performance was very inconsistent and could not be adjusted to my satisfaction.


The gold standard today seems to be a dual or quad ortho feed, but that is quite expensive for most hobbists.


Thanks again for all the points made and please continue to post ideas as that is how we all learn.

 

[mmewrench]

I would recommend the corotor II, for its simplicity and dependability. With good quality norsat lnb's you will be quite satisfied.

I've used bsc621 on a 10ft dish. After squeezing every bit of signal that I could (peaked the dish and the feedhorn), I picked up a used corotor with ancient lnbs (Macom for Cband, Gardiner for Ku) and threw it on the dish for an instant improvement.

I have 3 receivers slaved off of my dsr920 now and get excellent quality on both C and Ku band.

 

[anik]

so him giving a legit technical reason why the older C/KU feedhorn in alot of cases is better than the newer LNBF's is trolling? Thats a new one
Would it have been OK if I copy/pasted Brian's post?
(after all I have no commercial interest)

Iceberg, I was specifically referring to this post, in which Titanium more or less accused me of being a troll - referring to a discussion we'd had that had progressively gone downhill, he said "This interaction may have started as discussion, but it certainly became a troll." (See this post). And I'm assuming that he was not referring to his own posts when he said that.

Thing is that if you read that thread, a logical person might appreciate that following that exchange, if I asked a question of a specific person in an open forum, he was probably the very last person I'd want to hear from. Of course I am at a disadvantage here, since I am a mere user, while he is probably considered a valued member of this community. So I guess that means it's okay if he disrespects me, as he did in that thread, primarily because I dared to question the pricing of his product and to suggest that the ability to upgrade firmware using RS232 and Windows-based software is not exactly a great feature, considering that many new computers don't have RS-232 ports and that Windows is declining in popularity. But even though he carried the conversation forward as much as I did, since we each responded to the other's posts, in the end he made that comment about me being a troll. As long as I have been in this forum, I have never felt so disrespected by anyone, though I can see that I'm probably on the losing side here because I'm not selling anything and I don't participate that often (wonder why?).

That was what inspired the bit of snark in my previous comment in this thread. And suddenly I am told by eurosport that what I said could be considered flaming. Yet when he (Titanium) said almost exactly the same thing to me, and did it first, nobody batted an eye. Funny how that works.

(I know you will probably delete this comment, but I hope you will read it and at least look back at that other thread to see what I'm talking about. When you visit that thread, try to figure out who was making the more personal attacks first. I don't think that thread could be considered a finest moment for either of us, but I was trying to stick to the device itself and then to responding to what had been posted, although admittedly there finally came a point that I was truly fed up.)

 

[anik]

Since I have first hand experience with the swap he was asking about, I sent him a PM with info he was asking for, ie, I have a Corotor II with C/Ku Norsat LNBs laying the bench in my shop and an LNBF mounted on the dish.

Which was extremely helpful. Thank you!

 

[anik]

Anik, Titanium's response was informative in regard to the benefit of using a corotor-type feed as opposed to an LNBF, which is always a compromise. Perhaps I'm blind, but I didn't see any reference made to the ASC1. I'd say your comments were uncalled for. Food for thought.

See my response to Iceberg, if he doesn't choose to delete it. If you didn't read the other thread, you might not understand what precipitated my response. If it had been anyone else, I probably would not have responded that way.

In any case, that's not how I would typically respond to someone. In fact most of the time I just lurk occasionally and don't post at all, and given all this I think I should probably just go back to doing that.

 

[Titanium]

Anik,

Like you, I am a SatelliteGuy. No more, no less. I love the hobby and enjoy participation in the forums. My response to you was not tainted by any prior communication, nor will it be in the future.

You may not realize that I was the first importer of a combined C/KU LNBF to North America, the GEOSATpro CK1. I currently sell a revolutionary design of C-band LNBF. As a LNBF developer, I have a unique perspective of the strengths and weaknesses of each design and the challenges presented.

I did not post to this thread to promote any product or service. Just sharing applicable information gleaned from over 30 years in the industry as a product developer, distributor and in the field practical experience performing thousands of installs and service calls.

I choose to move forward on new threads and subjects with the understanding that we all have different views, preferences and apply our own filters. I value you as a person and as a fellow SatelliteGuy.

 

[KE4EST]

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