what are the pro's and con's of a ku / c-band combo lnbf ?
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The obvious pro is it gets both bands when it works.
The cons are that it will not receive both bands optimally and requires a large C-Band dish; it won't work well on anything smaller than an 8 footer.
The cons are that it will not receive both bands optimally and requires a large C-Band dish; it won't work well on anything smaller than an 8 footer.
If you have a mesh dish with ku the signal has to be spot on also. A solid dish would work better with ku.
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The focus points for Ku and C-band are different. You will either compromise Ku, or you will compromise C. I always installed mine to serve Ku over C-band, because Ku is harder to hit on the big dish, if you get it tweaked for Ku, generally C-band will be fine.
That being said, I am glad I dont use them anymore, they drove me nuts sometimes.
But they WILL work, if you take time to tune the dish and the LNB install.
That being said, I am glad I dont use them anymore, they drove me nuts sometimes.
But they WILL work, if you take time to tune the dish and the LNB install.
C/Ku LNBFs are a poor compromise. For professional results you need a C/Ku feedhorn and a set of LNBs.
Way too much! MSRP on that rig is $1200. It took some wheelin and dealin but I cut the price almost in half watching and waiting on EBAY and others.
But those are expensive PLL LNBs, my other dish has DROs that work very well and they have an MSRP of $330 for all 4LNBs The BullseyeII feed can be found for $300 nowadays.
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I use a NS741 with good results. I have it optimized for c-band reception and it performs as good as any affordable lnb/lnbf out there on c-band on my 6ft Sadoun. Ku reception is usually not as good as my 1 meter channel master but still very useful and will occasionally pull in something the 1 meter can’t.. One click on the vbox can sometimes be the difference in no reception and 90Q for KU.
Magic, do those lnbs come with that rubber ring on the connector, or is that something you added? Never saw them before. How bout those compression connectors too? I like the looks of those, easier to tighten I would think. What brand are they?
I was curious about the LNBF performance too so when I switched over from a Corotor II to a DMX 741 I did an A/B test using a few different satellites to see if or how much Q I lost in the swap. It's been a few years now since I did that and I don't remember exact numbers but if memory serves the loss from the Corotor to the DMX wasn't even worth mentioning. I think I posted those results on here when I did that so a search may find that thread.
The big seller for me on those LNBFs was the $$. Back when I switched over those DMX741s were available on fleabay for around $30/35 and the NS models that are available to day are about the same price. I'll have to say though that I do like the DMX version better because they had the 22Hz switch for Ku built into the LNBF. The NS model requires an external 22Hz switch for Ku which makes the BSC 621 more appealing to me at this point.
The big seller for me on those LNBFs was the $$. Back when I switched over those DMX741s were available on fleabay for around $30/35 and the NS models that are available to day are about the same price. I'll have to say though that I do like the DMX version better because they had the 22Hz switch for Ku built into the LNBF. The NS model requires an external 22Hz switch for Ku which makes the BSC 621 more appealing to me at this point.
The rubber is part of the compression fitting it get from Sadoun
http://www.sadoun.com/Sat/Products/PPC/PPC-EX6XLWS.htm
To me the NS741 not having a built in 22khz switch is a plus. Switches fail frequently so instead of having a bad lnbf when the switch fails I just replace the switch. Also I needed to use a diseqc switch with my setup due to a stationary dish set to 85w and don't have the loss of running the NS741 signals thru 2 switches.
Thanks magic, those I have not seen. Just bought another bag of the regular ppc fittings last week. The way I go through them, they won't last long lol, then i can try some of those.
In my experience, a Corotor system beats a LNBF when trying to receive a weak or marginal signal. A feedhorn with adjustable skew can detune adjacent satellites or terrestrial interference and optimize the skew for the desired transponder. This is especially important when DXing low angle satellites, the skew is affected by atmospheric changes in temperature, humidity, and pressure throughout the day and season. While many hobbyists systems are far from optimized, it makes sense to use the best products available.
On stronger transponders with no interference running a medium FEC like 2/3 or 3/4 on 8PSK, there will not be much difference between a quality LNBF and a Corotor. However, you will typically observe a dramatic difference on weak transponders, high FEC and/or higher modulation schemes like 16apsk / 32apsk. There is little room for error for these signals. A quality feedhorn, LNBs and an adjustable skew will optimize the signal so it can be locked or reliably received.
LNBFs are convenient, but they are a compromise.
On Ku, when I'm out at the dish, skew seems to need to be way off to affect much. Are you referring to C-band mainly ?
Signal errors affect all RF. Some frequencies are more prone to interference or disruption. The signal errors are occurring, but your receiver is not passing this information until the signal integrity nears the digital cliff. The digital cliff refers to the point where the received signal has too much missing or corrupted data to recreate the original information stream.
A STB's Signal Quality meter usually displays a reading that is post FEC. This means that the Forward Error Correction process is fixing the signal errors before the quality reading is calculated and displayed. A typical STB is displaying the lower Signal Quality reading, which is displayed if the FEC process cannot correct errors to produce full video and/or audio streams. Most STBs are also not correctly calibrated to reflect small changes in the Signal Quality. The display is usually highly averaged and/or dampened to produce a smoother response rather than a "jumpy" meter.
If you use a meter that displays the raw BER (Bit Error Rate) readings, you will observe the signal errors increase with even a slight dish or LNBF adjustment.
Here is a read that you might find interesting on geostationary ka/ku satellite link quality and interference: http://www.satprof.com/resources/pdf/Brooker_Antenna_Pointing_Accuracy.PDF
all good feed back. So how about this. I currently have a 36" geosat pro dish fixed and a 1.2 meter motorized dish, both are ku and on a switch. If I get another 1.2 meter solid dish and set it up as a fixed dish with a c-band only lnbf and scaler ring, could I pull in 103 west or 87 west by chance? I would like to pull in tnn if its 87 west or iontv if 103 west. 103 prefered. Also what is IPTV? I was looking at a reciever that has it as a feature.
IPTV is internet streaming. As for converting a 1.2m dish into a mini BUD and trying to get either 103w or 87w channels such as you mentioned, you don't have any chance whatsover of doing so. You need at least a 6ft dish, and even then you won't keep the Luken channels locked on 87w.
You do have a good chance of getting quite a few c-band channels on 99w though, and there may be a few other ones out there you'll get from time to time.
You do have a good chance of getting quite a few c-band channels on 99w though, and there may be a few other ones out there you'll get from time to time.
I guess what it all comes down to is as long as I'm able to lock feeds that most others get then I'm going to keep an LNBF. If it ever gets to a point where there's something up there that I want to watch and can't get, then I'll do something different.
FWIW, on my Winegard system with the DMX I'm able to lock that off skew Ku mux on 103w by bumping the dish a few clicks East so even that's not a problem at this point, not that there's that much on there that I actually want to watch.
Just saying..................
FWIW, on my Winegard system with the DMX I'm able to lock that off skew Ku mux on 103w by bumping the dish a few clicks East so even that's not a problem at this point, not that there's that much on there that I actually want to watch.
Just saying..................
I agree with primestar with regards to the luken mux on 87W. I can pull it in between 1/2 and 3/4 of the day right now with a 6ft. I don't think anything smaller than an 8ft would pull it in consistently all the time. Fortunately for me the top 10 countdown and 3rd shift are the main things I like on tnn (now heartland) and they come on at the optimal time for me to receive them.
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