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I would guess that the C/KU issue is more of an issue with the LNBF itself then the dish.

Where most people go wrong is they dont set the feed horn to the proper F/D distance. What happens as the dish heats and cools is that the reflector expands and contracts causing the focal point to change. This will be highly noticeable if the feed horn isnt set correctly.

I started with a KU setup. When I got my 8' C band dish I tried to get KU on mine but found that when I was aligned well with a C band sat, KU would not come in. I had to bump a click or so east/west on my vbox to get a signal. Even so, the signals were not as strong as they should have been and because of this some KU transponders wouldn't scan in at all. While some have had good results this appears to be the problem most people experience with a dual C/KU setup on a big dish. After messing with it for a while I decided to go back to my separate motorized KU dish and installed a Titanium C1PLL on my 8' for dedicated C band. Been happy ever since! :)

By the sounds of it, it sounds like you were on a side lobe with your dish. If everything is set up properly you should have no issues getting KU and C on the same dish, unless its LNA/LNB related.
 
You should have good success receiving C/KU with a quality feedhorn and C/KU LNBs. Check out the Chaparral Corotor feed with quality C and KU LNBs.

The C/KU LNBFs are not properly designed for KU reception. The feedhorn is tuned for C-band frequencies. The KU section catches whatever KU signals make it down the throat and fall out the back..... :D. The KU signals are usually out of phase (bouncing around in an untuned cavity) by the time they reach the KU probes.
 
I think that the C/KU LNBF can work, they just take a lot of work to get perfect, while a real C / KU LNB will give you much better performance and is a lot easier to setup.
 
I tried a C/Ku LNBF on my 7.5 foot Winegard. C was great...Ku not so much. My 1.2 meter CM/Primestar way out performs it.
 
Sounds like a poll should be set in motion.
C/Ku on specific size BUDs. 6, 6.1 to 8.5, and 8.6 to 9.9, 10ft or larger.
C & Ku on separate dishes.
Ku only
C only
Mini/Micro (C on an offset)
Anyone else employ my 'combo dish' Ku mounted to the BUD?
 
It also depends on the LNBF, I had 3 of the same brand / model LNBF that I got from WSI and one works good the other two you could get C or KU but not both at the same time reliably.
 
I prefer using the C-Band dish for C/Ku reception. But I use a feed horn and LNBs. I put in the effort and time to get good reception on Ku. While C/Ku reception is not easy and for the novice enthusiast, it is quite doable.
 
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Just for curiosity sake, how many on here besides me successfully us a combo C/Ku LNBF with your BUD?

I used to think I was successful with my BSC621 on a ten foot dish, until I picked up a used corotor with an ancient Gardiner ku lnb and an equally ancient macom lna for C band. The dish was already peaked well on the arc and I picked up 10 quality points across the arc on both bands. This was before S2 became popular. You may be pleased with your results sir, but you would be astounded by the improvement if you converted.

I've since upgraded to a new corotor II and PLL lnb's on a 12 foot dish. Now trees don't even get in the way
 
Any attempt to measure successful Ku reception on a bud would require taking all factors into account. Readings will vary by receiver, lnb type, dish used, etc. Location within the satellite footprint is a factor. Weather plays a role. Terrestrial interference factors in. All elements would need to be assessed for a proper evaluation and would probably prove very difficult. Also, success is subjective. One person may be happy getting only the strongest Ku signals and consider it a success while another may get those same signals and be disappointed that they are not getting more. A set of transponders on each satellite would need to be defined in order to make any evaluation valid. Things could get very complex. :coco :D
 
My two 6ft dishes still have DMSI BSC621 lnbfs on them. The 8ft dish has a pair of Chaparral lnbs and is C-band only.

Using the SH-200 SatHero meter to adjust the BSC621s I could get good C-band with acceptable Ku reception or good Ku with very little C-band. Since I've got a couple of 1meter motorized dishes for Ku I just optimized the lnbfs for C-band. I'm planning on replacing the 621s with C1PLLs from Titanium this summer.
 
There is a lot to be said for the simplicity of a 1 m ku dish. For one thing it can be aimed accurately using usals. The hardware is much cheaper (for the cost difference between a pll lnbf and a pll lnb, you could cover the cost of the 1m dish).

I plan on installing my 10' at the cabin this summer. I will probably go with a Titanium C1 and just move my 90cm fortec also.
 
You may be pleased with your results sir, but you would be astounded by the improvement if you converted.

Quite the contrary as I REMOVED a Corotor II and installed a DMX741S years ago and saw little if any difference at all across the board, ie, A/B testing when I made that switch. I will agree with Scott though that using one probably does require a GOOD dish and more fine tuning.

I guess this is moot point now as those combo LNBFs are no longer produced but I just can't help saying something when this topic comes up especially when someone stands to gain from users having to switch to the Corotor type feed horn. The old saying of "follow the money" applies then.:oldwink

I've gotten several of the combo LNBFs from ppl on here that pulled them off so hopefully I've got enough to last me a while. :oldwink I figure eventually DMS will do another production run and make them available again some time in the future if the hobby itself doesn't "tank" before then.
 
Quite interesting to explore the "follow the money" suggestion. Most of my business comes from selling LNBFs and a fraction of sales are from the sale of controllers with servo skew control. If this was really about following the money, I would be selling a combo C/KU and damn to reliable and predictable performance.

Combo C/KU LNBFs are still produced, but I am not aware of any North American distributor who carries them anymore. If it was such a great item, wouldn't you assume that we would be all over it?

I was the first distributor of a combo C/KU LNBF in 2004. Because we were unable to provide our customers with predictable and reliable performance on a variety of dish designs, I decided that it wasn't a product design that I wished to be associated with. It Is impossible to predict how combo C/KU unit will perform across the varied reflector designs with different focal lengths and ratios. The performance has many variables, mainly based on the convergence point providing an optimized pass-through of the feedhorn with the signal in correct phase when reaching the KU probes.

As the combo C/KU feedhorns are not the correct diameter and length to keep a KU frequency in phase. The feedhorn must be set in a position that allows the KU signal to reach the KU probes in phase. This optimized KU position may or may not be the correct focal point to optimize C-band reception.

Bottom line... Some dishes perform well with combo C/KU LNBFs and others have terrible performance.

It is possible to produce a combo C/KU with the integrated KU waveguide designs used in legacy feeds. Unfortunately the licensing for these designs are cost prohibitive to manufacture at this time. One design license is about to expire and it may be available for use in the next year without fees. Maybe a true performance combo C/KU LNBF will be available in the future, but it certainly doesn't exist with the current hardware. Sorry, but it isn't as easy to explain away by stating "follow the $$$$". :D
 
Quite the contrary as I REMOVED a Corotor II and installed a DMX741S years ago and saw little if any difference at all across the board, ie, A/B testing when I made that switch. I will agree with Scott though that using one probably does require a GOOD dish and more fine tuning.

I guess this is moot point now as those combo LNBFs are no longer produced but I just can't help saying something when this topic comes up especially when someone stands to gain from users having to switch to the Corotor type feed horn. The old saying of "follow the money" applies then.:oldwink

I've gotten several of the combo LNBFs from ppl on here that pulled them off so hopefully I've got enough to last me a while. :oldwink I figure eventually DMS will do another production run and make them available again some time in the future if the hobby itself doesn't "tank" before then.

I should add that when I received the corotor and LNB's I also received a 4DTV receiver with them. Therefore when I did the upgrade I had an adequate power supply to run the LNB's (steady 20+ volts). A quality LNB is a power hog and does not perform well at lower voltages. I also mentioned that the LNB's were ancient, but they were top of the line when new.
 
Just out curiosity, getting a corotor ll plus is just the beginning. I do not believe I have everything that is require to run the corotor. My receivers are not equip to run the servo motor. I have the microHD and Manhattan receivers. I was looking at eBay and saw a corotor II for $119.00, that does not include the lnbs, so what else do I need. I hope not a new receiver.
 
The corotor II PLUS feed would also need the servo motor and a control device There are several kit servo controllers as well as positioner controllers with skew control and of course legacy IRDs. Both of your receivers could interface with the kit or manufactured controllers.

The need for the extra hardware is one reason that folks often go with combo C/KU LNBFs or separate C and KU dishes.
 
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Digiwave 2.4 meter DWD240T

I miss the old days!

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