Which Ku LNB or LNBF?

[esteveW]

As I mentioned in my previous post. I'm not getting any Ku stuff. Just C band.

I'm looking for a source for a replacement Ku LNB and wonder if I'm going to have to replace my Corotor II Plus with something different.

I just got off the phone with Sadoun and all they have to offer is the complete replacement of my existing feed horn with a LNBF. Without a opportunity to examine the one they are recommending (GEOSAT CK1) I can't be sure it will fit my Button Hook mount. It only has a clamp strap and very little room for adjustment of the focal distance. It appears the feed horn OD might be the same diameter but not sure about this adjustment range.

I sure hate to spend the $45 to verify that my dish setup will get the Ku sat.s..

Are there any other big advantages to moving to the LNBFs??

Any comment or recommendation would be welcome.

Steve

 

[esteveW]

To add to my confusion. I just read the spec. on the GEOSAT CK1 and it appear the polorization is accomplished by DiSEQc. Now how will that work with my old FTA receivers?? Is that signal (voltage shift) in the Coax cable even from the old boxes?

How many other problems would this lead to??

Life was so simple when I was only concerned about elevation and declination angles.

Steve

 

[stogie5150]

I am ignorant when it comes to co-rotors, all I ever used is voltage controlled LNB's.

If you go to a voltage controlled LNB, you will no longer need an analog receiver to control the V/H. you will need something to move the dish still, but you will no longer need the analog receiver to change V/H.

If ALL you are using is a FTA box, the receiver will send 13v/18v to change the polarity for you. If you use an old time analog receiver WITH the FTA receivers, you will need a DC block to block the 18v coming out of the analog receiver so the FTA box can control the polarity properly.

If you are using a C/Ku LNB like the CK-1 (which is what I use), I just use a diseqc switch to switch between C and Ku. Port 1 is C, port 2 is Ku. And you set that up in your FTA box.

I really havent used an analog box with the voltage controlled LNB much, except a couple 4DTV's, but they CAN control a voltage controlled LNB, but NOT a diseqc switch.

I hope that helped.

EDIT:

As far as LNB placement goes, it is VERY critical for Ku. It took me quite a bit of time to get my dishes right. You WILL need some adjustment, as well as centering, centering is crucial with Ku.

 

[esteveW]

Thanks Crazed,

My only FTA receiver is hooked to a 'pizza pan' on a fixed mount. The BUD is hooked to an GI 450i analog receiver with a GI 905 sidecar for my C and Ku digital reception. The 905 has to work with a analog receiver (hence the term 'sidecar').

As far as I know, neither of these receivers have DiSEQc output and the polarity is controlled by the servo on the Corotor.

Steve

 

[Anole]

Then the path of least resistance might be to just get a Ku LNB to bolt onto your Chaparral feedhorn?
I have seen them on eBay for $15-30. Probably from one of the DMSI dealers.
That should restore signal, and then you can decide where to go from there.

. . . though, I'm not sure what there is on Ku in Analog, or that can be picked up by the 905 . . .
Is the 905 subscribed on C-band?

 

[esteveW]

I'll check out what is offered on eBay. I was just surprised that our "host" doesn't really have answers of recommendation on this situation. Nothing but the LNBF are offered on their site.

I'm not subscribed yet to either of the service providers. I just want to verify that my equipment is fully operational.

The way I read the opertion instruction for the 905 is to find the satellite with a digital signal that I want and then make sure the analog receiver is set to that satellite. I now have the GI 450i 'dialed in' on most of the satillites on the NPS list and getting a good analog reception.

I'm hoping someone can suggest a satellite that has some open feed in Ku that I can check out this one on.

Steve

 

[truckracer]

Your corotor is a superior feedhorn for c and ku on a bud. The c/ku lnbf's just suck on ku band imo. Get a good norsat ku lnb for your corotor or a california amplifier brand. Once your dish is properly aligned and tuned (assuming you big dish is ku capable) it will kill a dual band lnbf in performance. I have used both setups -corotor vs bulleseye II vs dual band lnbf and the corotor and bullseye wins hands down. Your corotor is commercial quality but requires a method of running the servo motor via an analog receiver or fta box with polorizer control like the old pansat 2500. I went back to the analog receiver and corotor. The lnbf method is certainly more simple but does not give the very best results. You could also use a seperate solid dish for ku controlled by a diseqc motor. A 90 cm, 100 cm or even a 1.2 ku dish will do great for ku properly setup with an invacom ku lnbf.

 

[esteveW]

Thanks for the encouragement Truckracer,
I have been looking at the NorSat products and narrowed down my search to a 4000A series, however I see others that offer more gain with higher noise figures. I'm not that technical and wonder if I should try something with a higher gain??

My existing, dead Ku LNB, didn't seem to mention the gain figure but did mention .6 db noise figure.

Thanks,

Steve

 

[esteveW]

Ku LNB ok!

I finally got my Ku LNB to work.

I still haven't hooked up my 905 sidecar with my analog GI 450i. However, just to verify that the LNB was working, I put a splitter in the Ku antenna cable and took the input signal to my ViewSat 7000 receiver. Then using the analog box, I located T5/L5 Galaxy 19. I only found one C band, in forgien language on 23. However, when I did a blind scan I found 84 channels of which 60 were unscrambled. All were in forgein language but good signal and quality. Enough to prove the the Ku is good.

I was surprised at how easy it was to do this and may is the ViewSat with my second BUD. Yah! I know I could just hook it to a Pizza Pan but I want to be able to move from satellite, horizon to horizon. Maybe not a perfect solution but a poor mans "sidecar".

Steve

 

[truckracer]

now what to do , flip your analog receiver to the next channel and do a scan for Horizontal channels. remember when you are surfing channels that on your fta screen when you see the channels go to a different polarity, flip your analog box channel and it will put you on the right polarity.

Now what you need is two high frequency voltage passing splitters.

use short coax jumpers out of your dsr 905 sidecar (the ones currently jumping to your analog box, and put a splitter on each cable (both c and ku). Now take one leg of the splitter that is "power passing" or maybe both legs are power passing...another short jumper to your analog box from each splitter.

now your remaining two unused ports are left...run a coax jumper from the c band splitter to a diseqc switch. run the ku to another port on the diseqc switch. Now take another jumper from the output of the diseqc switch into your fta receiver. remember the port numbers of diseqc switch that you have c and ku connected to.

in your fta receiver's antenna setup screen menu - each satellite will have a "diseqc" port option under antenna setup or satellite setup for each satellite. Make sure all you ku satellites go to the ku port and all the c band satellites go to the c band port.

you should be good to go...just remember your analog receiver has to be on a vertical or horizontal channel at all times to coincide with your fta receiver.

when you do a blind scan only scan one polarity at a time. if you do a complete scan it will log the same channels twice on both horizontal and vertical because your fta box does not know it is only getting one polarity from the corotor. Or as it shows it is finishing up its Horizontal scan, quickly flip your analog box to the next channel (vertical mode) and let it scan vertical.

 

[esteveW]

Thanks for all the valuable information. (some is still a bit too much to "digest". I'm working in small steps right now).

I was thinking that I would have to change analog channels sometime. I had noticed I was only getting the H one on the FTA directory.

I have had the 905 hooked up, according to the manual sometime ago but didn't have my elevation/declination dialed in yet. That all looks good now and the Ku function/signal seems to be good now. I'll hook that up one of these evenings.

Come to think of it, I still have to change the battery in the 905. I purchased a new 3.6 and battery over two weeks ago and the inflated price of about $17 at Radio Shack. I could have done a lot better at Allied or someplace on line, but I was in a hurry (and still haven't done it.) Looks fairly simple/straight forward, as I read the post about that procedure.

Thanks

Steve