Stacked "Beer can" LNBs on SC 75e dish

Status
Please reply by conversation.

cracklincrotch

SatelliteGuys Pro
Original poster
Sep 28, 2007
1,026
0
Halifax, Nova Scotia
I've got a couple of SC 75E dishes. One with the two standard LNBs with the built in 22khz switch, and one that uses the beer can band stacked LNBs, CalAmp PN 150462.

I've got one with the regular LNB set at 123/127W. Fine. Now I'm trying to get the one with the stacked LNBs going at 125/129W. Yes, I realize that AMC21 isn't quite at 125 yet but WhiteSprings is at 129 and I want that and I might as well be ready for PBS' move.

I can find the data transponder at 12078 V 30000 fine. But WSTV is at 11964 on a horizontal transponder.

Found this post here: http://www.satelliteguys.us/free-ai...e75-coolsat-4000-lnb-settings.html#post495721

My research agrees with this post, that the LO for the horizontal is 11325, making 11964H = 12539. But I can't find WSTV.

So I grab the LNB from my other SC dish and swap it in place and I can get WhiteSprings fine. Swap the LNBs back to the stacked ones and nothing.

I'd just blind scan but I got myself a smoking deal on a VS9000 HD. So good that I parted with my hardware blindscan box to get this one. Right now I wish I still had it. Anyway....

I'm sure I've just got the transponder frequency wrong. But now the wife has had enough of the swearing and wants to watch TV, I'm ready to hit the flat of beer. Anyone with some ideas why I can't find my H's? CalAmp #150462 LNBs.
 
take the Horizontal frequency from 24600

24600-11964=12636 V symbol rate


if you had blind scan, set the LNB LO to 13850 and blind scan V side only

thread on the issue (box with no blind scan)
http://www.satelliteguys.us/free-ai...t-8000-doesnt-like-bandtacked-technology.html

12636 doesn't work.

Since the LO for the H should be 11325 shouldn't that 24600 be 10750 + 11325 = 22075? Except that would make 11964 for WSTV = 10111, which I've tried, and that doesn't work either
 
Last edited:
12636 doesn't work.

Since the LO for the H should be 11325 shouldn't that 24600 be 10750 + 11325 = 22075? Except that would make 11964 for WSTV = 10111, which I've tried, and that doesn't work either

Your number of 12539 (11964+575) should be correct (with a LO of 10750) so 12539 V 2920 should work. Try changing the frequency by a few points either way, as I remember when I was using my stacked 60e LNB that it was off by a few points.

There is also another vertical frequency at 12104 V 3255 (at about half the strength of 12078).
 
Just did a test with my stacked Star Choice 60e LNB:

My Pansat has a stacked setting of 10750 V/10175 H, this is the correct setting for the LNB.

If you use as a standard LNB with a LO of 10750, then vertical frequencies are correct, and horizontal are 575 higher than actual (and it doesn't matter if you use a V or H, its the frequency that counts).

If you use as a standard LNB with a LO of 10175, the horizontal frequencies are correct, and the vertical are 575 lower than actual (and again, it doesn't matter if they are V or H).

Therefore, to get White Springs at 11964 (since it is the only channel on the satellite), use as a standard LNB with a LO of 10175.

EDIT: The 60e LNB is also a California Amplifer Part #150462
 
Last edited:
It's weird.

I tried a LO of 10175 to get 11964 H. My "S" drops from 49 to 11.

I'm wondering if my cable length has more to do with this problem than anything else.

In order to make my wife "happier" I moved my T90 (and my switch) out to the back of the house. Great she says. But I can't see anything past 127 out back due to the height of the house. That cable run is about 150' between the receiver and the switch. Now to get 129, I have to have that dish out front. That cable running from the switch to the front of the house hasn't been trimmed to length yet and is about 170'. So I'm running about 320' of RG6 to get from the LNB to the receiver.

I really think that might be it. Especially, when I program the Birdog for a LO of 10175, set up the transponder normally, it finds WSTV immediately when hooked up directly to the LNB on a five foot cable. Something to try.
 
Yep, it's the cable.

Just put a cable directly from the receiver to the LNB that was about 25' long. Bang. Get WhiteSprings with a LO of 10175. I can also get it at 12539 with a LO of 10750, like I expected. But otherwise I only get the verticals with the long loop out to the back and to the front of the house again.

Does this sound like a job for RG11?
 
Last edited:
I can find the data transponder at 12078 V 30000 fine. But WSTV is at 11964 on a horizontal transponder.
Well, trimming your cable should help, of course.
Are you saying you're losing signal because of high frequency loss due to bandstacking?
So I grab the LNB from my other SC dish and swap it in place and I can get WhiteSprings fine. Swap the LNBs back to the stacked ones and nothing.
So, if the non-bandstacked LNB works out front, why not leave it there?
Can you put the stacked out back?

What about putting the stand-alone dish closer to the T-90?
Perhaps a bit higher?
Or, have you considered raising the T-90?
 
Are you using the 2 in/2 out 22khz switch that usually came with the stacked LNB? If so, swap it out for a standard 22khz switch, might help.

You could always replace the stacked LNB with a new SC LNB, Ku Sat (in Montreal) sells them for $59.00 Canadian (plus tax & shipping) see: ExpressVu, Star Choice, Viewsat, Coolsat, Pansat & much more at Kusat.com, since 1997!

I've bought from them many times, great company.

Might be cheaper than running RG11!
 
Well, trimming your cable should help, of course.
Are you saying you're losing signal because of high frequency loss due to bandstacking?

I'm saying it's a definite maybe. ;) All I know is that with a short cable it works, and with a long long long one it doesn't.

What about putting the stand-alone dish closer to the T-90?
Perhaps a bit higher?
Or, have you considered raising the T-90?

I'm afraid of heights so I keep my dishes reasonably close to the ground.

I moved the T90 onto the fence in the back yard. It's a four foot fence. Can't go much higher on that. Thought about it going on its own post but I've been concerned about it swaying with the winds I get being on a hill and near the coast.

I've got the 123/127 dish on my 6"x6" clothes line post that's 8' tall. I could try moving the one I stuck out front at 129 on it, just above it. But I'd also have to lower the 123/127 dish and maybe the clothes line hook, so the dishes/clothes wouldn't block each other. 129 can't be that much lower to the horizon than 127 so it would be worth trying.
 
If you check any of the cable specifications, the attenuation increases with frequency for both RG-6 and RG-11. With the stacked LNBF's, you need to pay attention to your connectors, as you need a good connection. Try replacing your connectors and eliminate any switches or other connections. You probably have a connector with a bad crimp that works fine for the lower frequency, but is causing large losses with the higher frequency. Also check your RG-6 specs to see if it is rated for the higher frequency and how much loss you will have at the higher frequency. StarChoice also had subcriber units to un-stack the signals.
 
With a stacked LNB system, every link in your chain is a possible bottleneck, from cables to connectors. Any switches, splitters, connectors, grounding blocks, and cable must be able to pass 2.2 ghz or the show is off. The entire path must be 2.2 ghz compliant. That is really the only disadvantage (other than the modified TP frequencies) to going stacked...
 
I tried moving the dish out back, to shorten up the cable, and to see if I could get G27 but no luck. No problem with Horizons 1 though, or 123. But I already had those there. Just couldn't get 129.

So what I did was pick up another 75E without the stacked lnb, stuck it back up on the front of the house. Had to glue the mount back together as kids found the dish before I did but it works. I aimed the stacked dish at G25 and AMC4. Though now I need another 22khz switch to hook it up. I'll get those today.

When I had the stacked dish aimed at 123/127, I never did get a horizontal frequency because I couldn't figure out what the LO was. Now that I do there's plenty to try out on G25 that's horizontal. So if it's a connector I'll find out soon enough.
 
Status
Please reply by conversation.

Users Who Are Viewing This Thread (Total: 0, Members: 0, Guests: 0)

Who Read This Thread (Total Members: 1)