DiSEqC... Does it EVER work???

[Robbert]

Hi Everyone,

I have been frustrated with DiSEqC switches since I first started this hobby about a year ago. I had a 90cm dish with a HH100 motor and a circular and linear LNB on it. With one coax running to the dish, I wanted to have the ability to select either the circular or the linear LNB, so I used the 4-port DiSEqC switch that came with my Fortec receiver. From what I read here, it should be hooked up between the motor and the LNB's, which implied that it had to go outside. I hooked it up, and never got it to switch properly. Sometimes it would switch, and sometimes it wouldn't. Usually turning off LNB power in the Fortec setup and turning it back on would force a switch, but 9 out of 10 times changing channels/satellites would not.
I tried a few more DiSEqC switches and none of them would work reliably (tried a Spaun 4-port, Sadoun 2-port and Pansat 4-port). All of them exhibited unreliable switching behavior... I ended up blaming it either on the Fortec receiver, 100 ft cable run to the dish, or the motor inbetween the receiver and the switch, or the fact that the switch was outside. Basically, I gave up..

Now.. 6 months later, I have a second 90cm fixed dish and a dish-500 dish as well with dual legacy LNB's and I would like to switch between the Invacom LNB (linear) on the 90cm fixed dish and the two LNB's on the Dish-500 dish. I spent the time and effort to pull individual coax (Quad shield) wires from the dishes into the house (and put in a few extra runs, you never know!). So now I can have the DiSEqC switch closer to the receiver and inside, and no motors inbetween... And since I first started the hobby, I also have two more receivers. A Pansat 3500 and a Twinhan 102g PCI card. So I figured this should work... YEAH RIGHT!

What's happening now, regardless of the receiver or switch I use, it seems fine switching to the first LNB (the linear one) on the switch. That seems to be 100% reliable, but switching to the second or third (or fourth, I tried that port too) just isn't reliable. Sometimes it will switch there, but after a few seconds it switches back to LNB1. Other times nothing seems to happen..

What is going on???? Do I have the bad luck of having 4 bad DiSEqC switches and/or 3 bad receivers?? And yes, I did ALWAYS power down before messing with the DiSEqC switches.

I run MyTheatre on the PC with the PCI card and had it tuned to a channel on IA5 (BVN TV) which was using the first (Invacom) LNB on the switch. Then I went into the MyTheatre LNB/channel settings menu and clicked on the DiSEqC button (which brings up the DiSEqC menu). I chose LNB2 and clicked on "Do NOW". I see a brief interruption of the video/audio on the channel, but it goes right back. No matter whether I choose committed or non-committed, first or second switch... Can anyone who has MyTheatre and a switch try this for me? Does anyone know anything about the advanced DiSEqC setup parameters in MyTheatre? Could they help in any way?

Hope anyone can shed some light on this issue! At this point I just can't believe anyone out there has a switch that actually switches reliably..

Thanks,
Robbert

PS.
Sorry for the length of the post... Just wanted to let you guys know all the facts...

 

[Mr Tony]

Make sure you are doing the following
-when you add or remove a switch, make sure the receiver is OFF (using the switch in the back of the unit) so you don’t fry it
-when you set up the other ports, are you selecting them in the setup?

Reason I ask is right now I have 3 DiseQc switches being used outside (one to run 4 dishes..one to do the KU/DBS LNB on one motorized and one for LOS issues). All of these have been outside and has survived 2 (this will be 3) Minnesota winters with no issues

 

[Robbert]

Iceberg, thanks for your quick reply..

Yes, I am turning off the receiver in the back (with the switch). Or in case of the PC, it's shut down as well.

Not sure what you mean by if I set up the other ports whether or not I select them?? Obviously when I connect one of the circular LNB's to port #2 on the DiSEqC switch, I tell the receiver to switch to port #2 in the setup for the sat that the LNB is pointing to.

Now, do you ever have a situation where you switch channels and the DiSEqC does not switch at all? What brand DiSEqC's do you have? And more importantly, where did you get them? And did you ever try to control them with a Fortec Lifetime Ultra or a Twinhan PCI board? And if you did, did you ever have any trouble?

I'm thinking of bringing an oscilloscope home from work so I can look at the DiSEqC signal as it's being sent and compare it to what it should be (so I can see if my receivers are the problem or not).. Anyone have a link to a good technical resource on what I should see? I know DiSEqC uses 22KHz pulses to select a port, but what is the coding/timing used?

Thanks,
Robbert

 

[PipeDream]

Hi Everyone,

What is going on???? Do I have the bad luck of having 4 bad DiSEqC switches and/or 3 bad receivers?? And yes, I did ALWAYS power down before messing with the DiSEqC switches.

One thing I didn't see mentioned is whether your Linear LNB was "Standard" or "Universal." I'm under the opinion that diseqc switches are not good with Universal LNBs but 22KHz switches are. Also, it can be hard to find a good working diseqc switch at times. I had a new one that just wouldn't switch 100%,
a friend had 4 new switches of 3 different brands, so I offered to trade and took all 4 of his new ones to test. Only one worked 100% for my setup. 1 out of 5 in this test, and I doubt it is all that uncommon.

 

[Robbert]

The linear LNB is universal.. So it does use the 22KHz to switch from the low to the high band.. However, if that were to be the problem, I would expect the switch not to switch properly to the port that the universal is on.. Funny enough, that has been 100% reliable.. Switching to any of the other ports with circular LNB's on them is the part that's unreliable (and there is no 22KHz tone for those LNB's, just the 14/18V switching for L/R polarization).

In any case... Is there a specific brand/type of switch that is known to work decently?? I can't use a straight 22KHz switch since I have 3 sources I want to switch between (and possibly 4). Does anyone have a setup with a Twinhan 102G, DiSEqC, Univ. LNB on port 1, DSS LNB's on 2 and 3 and has it working?

 

[Mr Tony]

One thing I didn't see mentioned is whether your Linear LNB was "Standard" or "Universal." I'm under the opinion that diseqc switches are not good with Universal LNBs but 22KHz switches are. Also, it can be hard to find a good working diseqc switch at times. I had a new one that just wouldn't switch 100%,
a friend had 4 new switches of 3 different brands, so I offered to trade and took all 4 of his new ones to test. Only one worked 100% for my setup. 1 out of 5 in this test, and I doubt it is all that uncommon.

Universals don't work with 22K switches because there is a 22k switch built into the LNB. Diseqc switches work with Universals and 22k switches work with standard LNB's

 

[philhu]

I've had a few diseqc switches that did the same thing. They had a power problem.

They would always go to sat 1, but the others were unreliable

 

[Robbert]

Phil,

So what you're saying is that all my 4 switches are bad??? Or is the power problem something else you're referring to?

Thanks,
Robbert

 

[starman345]

Robbert,
In the diseqc setup of MyTheatre, after you make your changes, you need to press "do now", "ok" then click "apply" at the bottom. If you don't click apply the changes won't stick

 

[Robbert]

Right, I did hit apply when I actually made changes. But what I was wondering is, say, if I'm watching a channel on DiSEqC port 1, go into the setup, DiSEqC settings, choose another port (the channel is still playing in the background), hit DO NOW, shouldn't the port change to what I have selected and stay there until I do something else in the dialog (such as Apply/Ok/etc).

It appears that when I hit Do Now, it momentarily does something (the signal disappears), but then it comes back immediately, while I would have expected it to stay on port 2....

 

[rkrenicki]

I never liked my DiSEqC switch.. I found that sometimes it would take literally seconds to switch correctly, or it would fail back to port 1.

I ended up just sticking with one dish in the end.

Whenever I get my BUD setup, I will just stick with that and use a 4x4 multiswitch for my C/Ku and polarity selection... cant go wrong with good ole 22khz select.

 

[starman345]

Ok, I tried it. I have a very similar setup to yours. cir/universal lnbf's on a 1 meter dish. I have the universal lnbf on switch port #1, Circular on #2. In the diseqc window of MyTheatre(with a channel from AI5 playing in the background) I changed the port setting to committed #2, clicked do now and the picture froze, signal and quality fell to zero and stayed that way. I had to reset to committed#1 and select a channel before I had a picture/signal again.
You mentioned the addressing in MyTheatre...My spacelabs has a hex address of 15 marked on the switch...very small print. I believe you will find the switch settings on the expert window of MyTheatre, you can change the address there, the default is 10. My switch never worked reliably until I set it to 15. Something to try although this won't help you with your Ultra or Pansat.
Also, diseqc 1.0 and 2.0 require committed settings and diseqc 1.1 requires uncommitted.

 

[Tron]

Along the same lines of thought, do you have a standard set top converter that you can use to test the switches? There might be issues with MyTheatre or your PC DVB card/box...

 

[Anole]

Well, assuming it's not operator error with the software....
.... have you tried a Dish DP34 switch?
Not exactly a $5 to $12 switch, but it is reliable and it is diseqc.
(and I've never burned one out while changing cables with power on)

 

[Mr Tony]

a DP34 should only work with stacked LNB's...what happens with a non stacked LNB?

 

[Anole]

a DP34 should only work with stacked LNB's...what happens with a non stacked LNB?

Oh, I see your point.
Will it work on 13 volts?

Wonder if that 's why the $5 switches fail?
And maybe the users with shorter cables or higher "13v" have better luck??

 

[Mr Tony]

I don't know....I know in Dish land you cant mix Legacy & DishPro equipment. Legacy would be nonstacked

 

[Robbert]

Ok, I tried it. I have a very similar setup to yours. cir/universal lnbf's on a 1 meter dish. I have the universal lnbf on switch port #1, Circular on #2. In the diseqc window of MyTheatre(with a channel from AI5 playing in the background) I changed the port setting to committed #2, clicked do now and the picture froze, signal and quality fell to zero and stayed that way. I had to reset to committed#1 and select a channel before I had a picture/signal again.

Thanks for testing that for me. At least this is a quicker way for me to find out if a new DiSEqC works.. I ordered two new ones.. One from Spaun and a new type of PanSat.... We'll see what happens when they come in. If they also don't work, they'll be on eBay..

You mentioned the addressing in MyTheatre...My spacelabs has a hex address of 15 marked on the switch...very small print. I believe you will find the switch settings on the expert window of MyTheatre, you can change the address there, the default is 10. My switch never worked reliably until I set it to 15. Something to try although this won't help you with your Ultra or Pansat.
Also, diseqc 1.0 and 2.0 require committed settings and diseqc 1.1 requires uncommitted.

MyTheatre is set to 10 Hex, and I tried changing it to 15, but that resulted in no switching at all.. So I left it on 10 Hex. Do you know what the second number does? (I believe it's labeled type/retries).. I fiddled a little with it, but no obvious changes from the original situation.
As for the DP34, what is the consensus on that? Won't work I presume due to the fact that my LNB's are not stacked?
And yes, I tried these switches with a Pansat 3500S and a Fortec Lifetime Ultra as well. Same results: Unreliable switching, but most of the time with the Fortec, no switching at all! (fixed to input 1, although sometimes I could force it to 2 or 3 by going to the sat setup and briefly turning off LNB power and turning it back on...)
Thanks for all your help so far.. I'll be sure to let you know what happens when I get these other 2 switches in.. I've got my fingers crossed!!
Robbert

 

[Anole]

dp34

I don't know....
I know in Dish land you cant mix Legacy & DishPro equipment.
Legacy would be nonstacked

Yes, quite true.
But I think that's a limitation of the receiver's programming, not a technical problem.

When I first read about the cheap diseqc switches, I was amused to see them used with what amounts to legacy LNBs.
With proper programming, you should be able to mix stacked and non-stacked LNBs on a diseqc switch under control of MyTheatre.

As for the suggestion of the DP34, it wasn't a claim. Just a suggestion.
Would be nice to find a reliable solution.
If there's some technical reason it won't/can't work, that would be good to know, too.

 

[Robbert]

As for the DP34, what is the consensus on that? Won't work I presume due to the fact that my LNB's are not stacked?

Ok, did a little research on how the DP34 works, and yeah, that won't work (I won't see half of the transponders because my LNB's are not stacked).. But I noticed Dish has something called the SW64 as well. Now, I have a single output on my linear LNB, but it would be easy enough to upgrade that to a dual LNB so I can fully populate the SW64. I don't recall seeing a linear LNB for sale anywhere that wasn't universal (but since I'm pointing at IA5, I don't need universal), so would this work:

Receivers (4 max)
| | | |
**** SW 64 ****
|-DSS LNB 1A
|- DSS LNB 1B
|- DSS LNB 2A
|- DSS LNB 2B
|- 22KHz Tone generator ---- UNIV LNB 3A
|- 22KHz Tone generator ---- UNIV LNB 3B


(hope this little ASCII diagram makes sense... )
And if so.. How does the receiver select the dish it wants to use (22KHz??DiSEqC?? 13/18V??) And could this work with MyTheatre and/or a standard set-top receiver such as the Fortec?
Thanks!