ASC421 and the C-Band LNBF - whence KU?

[kulakovich]

Greetings!

Happy Holidays.

A question to the ASC421/C-band LNBF crowd out there - what are you doing for KU? Individual dishes? Retrofeed? How are you receiving your KU? Bracket a KU LNBF on?

I am about to take the plunge.

Thanks the many,
Kulakovich

 

[Shawn95GT]

Some guys are doing a seperate fixed dish for X4.

I went whole-hog and replaced the ASC421 with a C/Ku FeedHorn.

There were some C/Ku voltage switched combo LNBFs made but I think they've been pretty much abandoned. I see them on Ebay now and then.

I think Sadoun is working on getting a combo C/Ku LNBF available for us .

 

[gizzer777]

KU on bud

Greetings!
Happy Holidays.
A question to the ASC421/C-band LNBF crowd out there - what are you doing for KU? Individual dishes? Retrofeed? How are you receiving your KU? Bracket a KU LNBF on?
I am about to take the plunge.
Thanks the many,
Kulakovich

KU is much more demanding on BUD than C Band. I get X4 just fine on my 8 ft winegard with .6 deg KU LNB. (In Reno Nevada) First I tuned to G4 and then X4 came in great (same location)

 

[iammike]

The ASC421 is a nice lnbf to get your feet wet, I used one for a while. To get the most out of your BUD you need more though. I'm using this:

http://www.thesatelliteshop.net/hypercart/PictureFrame.asp?Sku=cbandcombo1

The one problem I had with the ASC421, was getting the skew exactly right. I can't count how many times I had that stupid thing off the dish making what I thought were slight adjustments. When you have a servo motor, you can control skew from your receiver and can make much finer adjustments. A lot of folks just starting out don't realize how important skew is. The dish can be perfectly aligned, but if the skew is off you'll get snow or no picture at all. The other nice thing is having KU on the same feedhorn. Even if you do put up another dish for KU, the 4dtv receivers are still going to want to move your dish. There isn't any way to tell the receiver not to move the dish for a particular sat.

 

[gizzer777]

looks like a nice setup

The ASC421 is a nice lnbf to get your feet wet, I used one for a while. To get the most out of your BUD you need more though. I'm using this:
http://www.thesatelliteshop.net/hypercart/PictureFrame.asp?Sku=cbandcombo1
The one problem I had with the ASC421, was getting the skew exactly right. I can't count how many times I had that stupid thing off the dish making what I thought were slight adjustments. When you have a servo motor, you can control skew from your receiver and can make much finer adjustments. A lot of folks just starting out don't realize how important skew is. The dish can be perfectly aligned, but if the skew is off you'll get snow or no picture at all. The other nice thing is having KU on the same feedhorn. Even if you do put up another dish for KU, the 4dtv receivers are still going to want to move your dish. There isn't any way to tell the receiver not to move the dish for a particular sat.

I also have the Co Rotor II (over 10 yrs) and it is great. Using a norsta
t 8000 15 deg C LNB and norstat .6 KU LNB on the rotor II. Geat stuff even after 10yrs

 

[kulakovich]

The ASC421 is a nice lnbf to get your feet wet, I used one for a while. To get the most out of your BUD you need more though. I'm using this:
http://www.thesatelliteshop.net/hypercart/PictureFrame.asp?Sku=cbandcombo1
The one problem I had with the ASC421, was getting the skew exactly right. I can't count how many times I had that stupid thing off the dish making what I thought were slight adjustments.

Ok - I should better illustrate my situation: I have a Chapparal C-band LNB/Feedhorn. I have one of those goofy "retrofeeds" clamped to the underside that you can get on eBay, for Ku. I need to improve my signal. I've been doing BUD for about 3 years now, am pretty comfortable. I just fried another C LNB, right before driving a 8' copper grounding rod to ground my system.
The "real" issue for me: Do I go Corotor with C/Ku or do I do LNBF and keep my retrofeed doohicky. Of course the ASC421 is cheap, but this is a mobile BUD, so I will definitely need skew control I think.
So should I drop the cash on the corotor instead of the ASC421? That would seem to be the case - yea or nay?
Thanks again for your time,
kulakovich

 

[truckracer]

I did a "west virginia engineering" method of c and KU. You will love this:

I started with a 20 degree astrotel c-band lnbf and a .6 KU dms internation lnbf.
I removed the plastic housing from the KU lnbf.
Trimmed outer most 2 scalar rings from the ku lnbf making it about 1" in diameter.
Used a 1" hole saw and cut hole in center rear end of the astrotel c-band lnbf.
used some sand paper to smooth edges and make the KU lnbf fit snug into the rear of the c-band lnbf.

*Aligned vertical and horizontal probes of lnbf's by looking down the throad of the c-band lnbf. (so the skew will be the same for both lnbf's).

used some hardware store adhesive to (steel putty) to adhere the lnbf's together.

Mounted it on the dish-peaked the skew and f/d on ku band .
Two RG-6 quad coax runs 200ft from the backyard to the house 1 or KU and 1 for C band.

Ran each feed into my dsr-905 (sat in C , sat in K)
Out of the DSR-905 with short jumpers to two High frequency TruSpec splitters (both ports power pass)
One run from each splitter to a 2x1 diseqc switch, from there to my Fortec ultra receiver (free to air dvb)

Other two runs from splitters go to analog orb-7500 c/ku receiver.

I get great signals on all C and KU sats using a 7.5' mesh dish.

Hbo / Max channels on G1 quality 50-64. (dsr-905 4dtv)
equity channels on G-10ku 11720V tp - 85-92% quality on fortec ultra

 

[WyrTwister]

Ok - I should better illustrate my situation: I have a Chapparal C-band LNB/Feedhorn. I have one of those goofy "retrofeeds" clamped to the underside that you can get on eBay, for Ku. I need to improve my signal. I've been doing BUD for about 3 years now, am pretty comfortable. I just fried another C LNB, right before driving a 8' copper grounding rod to ground my system.
The "real" issue for me: Do I go Corotor with C/Ku or do I do LNBF and keep my retrofeed doohicky. Of course the ASC421 is cheap, but this is a mobile BUD, so I will definitely need skew control I think.
So should I drop the cash on the corotor instead of the ASC421? That would seem to be the case - yea or nay?
Thanks again for your time,
kulakovich

Depends on what kinds of receiver you plan to use . An analog receiver works better with a LNB .

Unless the receiver has a set of connectors for the polar rotor ( like the Pansat ) , a DVB-S receiver is best suited to use a volage switching LNBF .

Wyr

 

[iammike]

I did a "west virginia engineering" method of c and KU.

Hey truckracer, I'm familiar with some of those West Virginia engineering methods. I grew up a couple hours north of you in New Martinsville. Sounds like your method works well.

If the OP isn't as sophisticated as us WV boys, I'd recommend going with the Chapparal Corotor II. I think it would get a better signal than the Ebay special, but that's just an opinion.

 

[kulakovich]

Hey truckracer, I'm familiar with some of those West Virginia engineering methods. I grew up a couple hours north of you in New Martinsville. Sounds like your method works well.
If the OP isn't as sophisticated as us WV boys, I'd recommend going with the Chapparal Corotor II. I think it would get a better signal than the Ebay special, but that's just an opinion.

Truckracer and iammike - I'd be comfortable drilling the hole - I'd seen the ku-in-the-scalar-rings before as a non-corotor substitute. But I am getting tired of fixing all of my willy-nilly patchwork, and I always suspect my drilling, rigging, taping and etc. This is a 'once and for all' type thing, like driving that grounding rod at long last.
I also used nearly a spool of RG6 and did the dual-run thing for both LNBs all the way back to the house. Heck, my lines are still surface run, half the problems I have no doubt. I am burrying them in the Spring, and will put a switch out there for the dish (I also have a 7.5 mesh, primefocus) so I can use the second run for another dish - probably fixed on AMC6 for NASA - where I will then use the mighty ASC421 no doubt!
From what I am reading, I need skew control since the dish moves, and it'd be better over all. I am on a GI650i for analog and a Pansat2500a for FTA with the VBOX for disecq to analog motor drive. I have a 102G twinhan, but my processor is too old to really drive it. Hey, one thing at a time. I can't even receive C right now!
Thanks for all your help,
kulakovich

 

[truckracer]

Hey guys, glad to hear there is another country boy on the satellite scene. LOL
I would guess that you may get a better signal with professionally engineered equipment over my "Hillbilly feedhorn design" but actually i do get great signal quality even on G-1 hbo/max channels that everyone has a hard time with.

Now that's not say the signal quality couldn't go up with a corotor II and some high quality pll lnb's.

The dual lnbf c-ku setup works really well for my free to air setup since most all free to air receivers rely on voltage to switch polarities.

As far as skew is concerned, as the dish moves on the polar mount, the skew pretty well tracks the arc. In fact you can easliy see how many degrees plus or minus the skew is by running the dish all the way west to amc-8 (139 degrees) and us a plumb bob from the lnbf and see how many degrees it is "skewed".

You still have no automatic control of skew with the lnbf arrangement but I have found that with careful tuning of the lnbf's you can get great analog and digital signals without skew control. My polar mount seems to automatically skew the lnbf arrangement pretty well, about like how an sg-2100 h-h motor does a ku free to air dish.
trucker

 

[drhydro]

I have been using a Corotor for about 7 months now on my 10' perf aluminum BUD. I am very happy with signal quality, even though i am using a .7 KU lnb and a 20 degree c band LNB. I get the equity channels on g10 in at around ~70% on my pansat 2700a. I was able to pick up my corotor for under 100.00 with both LNBS off of fleabay (used).

 

[kulakovich]

I just cut/crimped/replaced the ends off my c-band line at the dish based. Corroded as all get-out. I had heat-shrunk the line last Summer, but somehow the shrink had expanded and eventually water set in. I don't think the LNB was harmed. That's what pretty much started my question. Now I am back up to almost 79% on AMC-6 in the C, for NASAtv.

I lucked out on fleabay a while back and got a nice DRO Ku Norsat on the cheap ~40 or so. I always search for norsat and nrosat to 'keep and eye out'.

Right now I can only get half of IA-5 Ku, the 12177 channels are a mystery. They were there. Now, who knows?

I will probably hold off on the corotorII for now since my 'half assed' retro feed thing is still working. I thought it was toast. It's one of the black plastic cones that hangs the Ku lnb off the bottom of the scalar rings about a foot and perhaps 9" off center. Hey, works for me.