Analog to Digital

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Ironsides

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I have a question or maybe a couple. I have a C-Band dish, Uniden Supra, ok I have my Dreambox 7020 connected directly to the C-Band Lnb as instructed in the manual.

The Supra is connected to the Loop out on the Dreambox and this is fine I should think.

OK The Dreambox manual suggests when I want to watch Analog I need to place the Dreambox in deep standby.

I used the Comp out on both receivers so I can watch either one on the tv or both using PIP.

The thing is if The Uniden is off I can't see any video from C-Band on the Digital side. Another words they both have to be on. Now I understand the LNB needs power but what is confusing about it is this. If I turn off both receivers and leave them off for a few minutes. I can turn on the Dreambox and watch tv on the digital channels. However I notice glitches from time to time. Now I can watch TV on my KU dish and don't have any issue at all with glitches so this tells me the power for the lnb is present from Dreambox.

It boggles my mind about turning them both on and off...You would just have to see it...

I can leave them both on and it seems nothing strange is going on or does it seem to have any issues to either receiver even when switching the power off and on. I can see the digital stuff for a couple of minutes and then it goes black when I turn off the Uniden but I can change to a different channel say like going from a VERT to a HORZ and that channel will be there...holy cow that is confusing...

Right now I just leave them both on and so far no issues..but I'd like to understand what in hell is going on..with that....
 
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Ironsides

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Ummm

wow Nobody here can give correct instructions on how to correctly slave 2 receivers?? That is even more boggeling than my slaving issues! Oh well...
Sadly walks away with head down.....All I am asking is how to correctly slave two receivers...
 
rv1pop

rv1pop

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I do not really understand the questions as I do not run any of those receivers and I am not using C band YET!

That said.... I kinda sounds to me that the Analog rcvr is controling polarity and after the power supply bleeds down the polarity drifts to where gravity wants it, therefore -- weird!
 
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Ironsides

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Yes it is

Yes it is and I can tell you something even more strange! I was playing with this and found you can Leave the Dreambox in deep standby and Turn the Uniden on and choose the polarity. Turn the Uniden off and leave it off for say a couple of minutes. Then Bring the Dreambox out of deep standby and Bada Bing on the correct polarity and watch tv without any flaws. Uniden off the entire time....

Ok further tested this, switched the Dreambox out stuck in a Pansat 2700 and same results as before.

Tested further Neusat in line and same results as before...

Went another step stuck in a Pansat 2500 and same results...

Switched out again and went to PC based Twinhan and SAME restults! Exactly the same results!!!!

So last test disconnect the loop out and see what happens...

The Uniden must be on to change polarity with a couple of my receivers as neither can switch a servo and only can do diseqc. So I have to use the Uniden to switch polairty and to move the dish otherwise it would be out of the system...

Now Almost every one of these give directions on how to use the loop out and none of them really mention leaving the Analog on or off....with exception Dreambox says to watch Analog the Drembox must be in Deep Standby...

Not so if you use the comp out and have more video selections on the TV but perhaps they have other reasons they do not mention....

Ok Loop out totally disconnected...

Same results as before so it makes no difference concerning the polarity.
That says it has something to do with the Uniden...

If you turn the Uniden on select the polarity and leave it there a couple of minutes then turn it off...and leave off a few minutes
Turn on the other receiver it will be on the last polarity and you are watching tv...

Otherwise it switches all on it's on and you end on something not selected..the whole thing is strange but it does tell me Looping makes no differces to the LNB....,
 
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Lak7

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The thing is if The Uniden is off I can't see any video from C-Band on the Digital side. Another words they both have to be on.
Very possible, with out power from the Uniden, the servo could move. Another thing possible is that the Dreambox is not supplying enough power to the LNB.
The best way to slave with servo Controlled Feed is use High Freq Splitters as seen here...
sadoun.com/Sat/Installation/Multi-LNBF/BUD-Slave-KIT-II.htm
The Analog should be on to control polarity.

To get around using a slave kit, a Voltage Controlled LNBF can be used, then either unit can control the polarity.
 
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Ironsides

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Very possible, with out power from the Uniden, the servo could move. Another thing possible is that the Dreambox is not supplying enough power to the LNB.
The best way to slave with servo Controlled Feed is use High Freq Splitters as seen here...
sadoun.com/Sat/Installation/Multi-LNBF/BUD-Slave-KIT-II.htm
The Analog should be on to control polarity.

To get around using a slave kit, a Voltage Controlled LNBF can be used, then either unit can control the polarity.


Thanks guys for the input, I did discover though the Uniden can be off and I can watch TV I didn't realize it had switched polarity earlier on when testing this. But regardless to the Dreambox concerning the Uniden on or off I can watch TV...I just have to go to a channel the Uniden defaults to when turning it off...Which by the way seems to be luck of the draw concerning polarity with the Uniden. It just does whatever it decides to do! LOL

I looked at the slave kits but in my case using One C-Band lnb and nothing else I don't understand the need for splitters but they might know something I don't.

All the directions for using the Loop out are very simple. Hook the main LNB up to the Master receiver and loop out to the slave, allowing both receivers to use the lnb. In a way the loop out it acts as a splitter just built in to the receiver?

Being I don't need to see the C-Band from the Analog the easiest thing to do is just disconnect the Loop out and use the Uniden to move the dish and switch the polarity...

I did also discover that ALL the receivers in my test can power the C-Band LNB without any help from the Uniden...Dreambox has no problems powering the LNB...

I think my Pansat 2500 can also switch polarity which I am looking into now. Or the 2700 might can switch it...using the servo...


I did some reading and Yes the Pansat's either can adjust, skew and polarity using a servo...Which is cool they added this! That said kind of sad though that Dreambox uses Only DiseQC and has no means to switch a servo. I use the Dreambox because I can record and watch a show later on....Oh well can't have everything...
 
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Lak7

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I did also discover that ALL the receivers in my test can power the C-Band LNB without any help from the Uniden
Most LNBs like 18 - 24 volts, and the 13volts from DVB Receiver for Vertical can be just a bit weak. That's why the use of High Freq Splitters, let the Analog Receiver power the LNB with 20volts for either Horz or Vertical.
 
B.J.

B.J.

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Oct 15, 2008
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Thanks guys for the input, I did discover though the Uniden can be off and I can watch TV I didn't realize it had switched polarity earlier on when testing this. But regardless to the Dreambox concerning the Uniden on or off I can watch TV...I just have to go to a channel the Uniden defaults to when turning it off...Which by the way seems to be luck of the draw concerning polarity with the Uniden. It just does whatever it decides to do! LOL
First of all, by turning off, I assume you mean switching off via the remote or front pannel button or something, not by unplugging or using power switch in the back? If so, then the Uniden is still sending power to the LNB, so it isn't really "off". However, with respect to it having a default channel, most receivers will not switch to any default channel, but *IF* there is a VCII module installed, the VCII module will tell the receiver to start changing channels trying to find a VCII channel to sit on. There aren't many of those left, so it may look for a while then stop, or it may keep looking. But in any case, if the Uniden happens to have a VCII module, you might as well pull that out. Once you've done that, I really doubt that it will change channel or change polarity. I'm assuming that you have something like a Chaparral CoRotor with a polarotor. Most polarotors will remain at whatever setting they are left on, unless it is VERY OLD.



I looked at the slave kits but in my case using One C-Band lnb and nothing else I don't understand the need for splitters but they might know something I don't.
You can get along without the splitter if you don't intend to watch any analog signals, however if you do that, which means powering the LNBs from the digital receiver, then you should set all channels on the digital receiver as being horizontal, because many LNBs don't work well at 13V, which the digital receiver will be putting out when set on vertical. But since you're using the Uniden for polarity anyway, it seems like you might as well retain the capability of viewing analog.


All the directions for using the Loop out are very simple. Hook the main LNB up to the Master receiver and loop out to the slave, allowing both receivers to use the lnb. In a way the loop out it acts as a splitter just built in to the receiver?

As has been discussed, this may work, and it may result in you destroying something. If you want to take the risk, fine. I prefer to use DC blocks rather than connecting a slave directly to the passthru.


I did also discover that ALL the receivers in my test can power the C-Band LNB without any help from the Uniden...Dreambox has no problems powering the LNB...

As mentioned above, I doubt that you have demonstrated that, at least through your current configuration, because unless you've unplugged the Uniden, or switched it off at the back, then the Uniden was actually still on and you have been getting power from the Uniden all along. You can definately power the LNB from the digital receiver, however you need to find out how well your LNBs work at 13V, or see to it that the receiver always provides 18V.


I think my Pansat 2500 can also switch polarity which I am looking into now. Or the 2700 might can switch it...using the servo...


I did some reading and Yes the Pansat's either can adjust, skew and polarity using a servo...Which is cool they added this! That said kind of sad though that Dreambox uses Only DiseQC and has no means to switch a servo. I use the Dreambox because I can record and watch a show later on....Oh well can't have everything...
DiseqC has nothing to do with polarity. The Dreambox uses voltage to switch polarity, but only on lnbfs.
 
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Ironsides

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Thank you

Thank you BJ for your input! Excellent advice! And any others that has suggested ideas...

Ok powering the Uniden, makes no differences if it's unplugged or not as far as the other receiver goes and what takes place.

Addressing the DC block that is the reason for my posting as I do not wish to take any chances.

The loop out has a DC block on it but honestly I can't see any differences either way. I did try it without it but I replaced it and I do have a DC block on the loop out of my Dreambox. Also I have surge protectors on both boxes...

As you suggested I changed the settings in the Menu to 18 volts for both H/V settings. I could see no differences...Don't really like that because seems it just strains the power supply more but you have to do what you have too..


Ok With an older C-Band system as you already know they depended on the servo to switch polarity. My Pansats can use the same connections and work with wiring that is currently in place with my C-Band. Unless I am totally confused as to how that worked. At any rate The Dreambox does not have any way to change the polarity other than sending a signal down the coax which I was refering to as Diseqc. Sorry for the Confusion on that. Thanks for clearing that up for me...

The only thing I have not tried is removing the VCII board which is my next step and yes no point in leaving that in any longer. All it is doing is robbing power from the power supply anyway.

Right now due to my lack of splitters and lack of understanding I felt my safest bet was to just totally unhook the Uniden from the Dreambox or others and just use it to move the dish and switch the h/v and not worry about getting any video from it.

Even using the DC blocks and trying to be as safe as possible I just did not want to take any chances on ruining either the Uniden or Dreambox and of course the LNB could be damaged....
So untill I get the proper splitters and slaving parts I will just leave it totally unhooked from the LNB and loop out...
 
B.J.

B.J.

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Oct 15, 2008
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...
Ok With an older C-Band system as you already know they depended on the servo to switch polarity. My Pansats can use the same connections and work with wiring that is currently in place with my C-Band. Unless I am totally confused as to how that worked. At any rate The Dreambox does not have any way to change the polarity other than sending a signal down the coax which I was refering to as Diseqc. Sorry for the Confusion on that. Thanks for clearing that up for me...
DiseqC is a 22khz signal that's modulated with data to control switches and tell motors where to go. Polarity on the FTA receivers is not determined by a signal on the coax, it determined by the lnbf voltage. For H or L, it sends 18V to the lnbf, and the lnbf knows to set polarity to H/L . For V/R 13V is used. Regular C/Ku LNBs are designed to work at ~18V, +/- a few volts. Most will work down at 13V, but some don't, and the ones that do work may not work quite as well.

Right now due to my lack of splitters and lack of understanding I felt my safest bet was to just totally unhook the Uniden from the Dreambox or others and just use it to move the dish and switch the h/v and not worry about getting any video from it.
There isn't much analog left, but there is a bit. However I do use it to find and peak a few sats. However I had the same idea a while ago, ie to just disconnect the analog, and when I need it, just hook it up to the passthru of one of the FTA receivers. However after doing that, my digital reception actually got worse for some reason. Only thing I can figure is that the power supplys on my analog receivers are better than the power supplies on the digital receivers. The power supplies on the old analog receivers are big old conventional power supplies with big transformers and capacitors, but the supplies on the FTA receivers are little switching power supplies, and I think they tend to emit higher freq noise than is likely from the low line freq noise you might get on a conventional power supply. But whatever the reason, on weak transponders, I've had better luck slaving my digital receiver off the analog than hooking the LNB up directly to the digital receiver. Isn't logical, but that's what I've found.
Even using the DC blocks and trying to be as safe as possible I just did not want to take any chances on ruining either the Uniden or Dreambox and of course the LNB could be damaged.....

Pretty hard to hurt the LNB. The danger is that the 2 power supplies would be fighting each other.
 
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Ironsides

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Thanks again

Thanks again BJ nice read and good advice.

Just for kicks I tried your setup, going for the Analog as the Master and the digital as the slave. In this case, I didn't have good luck, had to retune and reposition, even reskew for some reasons. But it did work after tuning.

I went back to my original setup and just left the loop out unconnected.

This has been very interesting and holy cow how opinions differ.

I did some research and downloaded several manuals for different digital and analog receivers. Every single one of them that shows or discribes a loop out... suggest the following when using C-Band and most state a 4DTV box or analog box.

FTA Digital Box directly to the C-Band LNB
Analog box directly to the loopout of course they do show you which ports to use.

None of these manuals suggests a use of DC Blocks, Surge Protectors OR turning off either receiver to protect anything.

That is what I find to be questionable as to why they wouldn't warn you of power related problems or any problems when using the Loop out. Or suggest turning off a box or using DC blocks and so on...Totally confuses me here...


Ok LNBF question???
Here I do understand the V/H is changed by voltage (example 14 volts for vertical and 18 volts for the horzontal)

Ok here is my question if the FTA box switches the V/H and the voltages change. The coax is its only connection so the voltage would have to travel the feedline (coax) to the LNBF in order for the changes to take place is that not correct? In my opinion it would have to be correct...

In The case of my C-Band LNB the coax did not make any changes to the polarity. The servo which is controlled by wiring that returns back to the receiver is how the polarity is changed. That wiring is totally different than coax. I think it's 2 wires only and then I have 3 more wires that goes to the dish mover.

In order for Pansat to change the polarity you have to connect those 2 wires to it when connecting to my C-Band LNB. Otherwise it sits on the same polarity and makes no changes no matter how you tell it in the menu.
Those wires have to connect to the Pansat!

In the case of Dreambox it has no connection for Polarity Servo it relays on the coax and voltages to the LNB from DB to change the polarity. Dream must not have considered it's use with older C-Band LNBs here in the States. Wow what a mistake that is with all the old C-Band stuff laying around that is servo controlled. My system is about 18 to 20 years old now but honestly has 100 times better Video than Any Digital FTA box I have ever seen even the HD versions have a hard time beating out that Analog C-Band video.

Pansat diff has a leg up on them in this case for using Older Equipment...
 
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Lak7

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The servo which is controlled by wiring that returns back to the receiver is how the polarity is changed.
I don't know about a Uniden Receiver, but a 4DTV receiver has an LNBF option, so it can control a Voltage Controlled LNBF, making the Servo Wires unnecessary.
 
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Lak7

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An after thought to your unsuccessful attempt today....
When setting up an LNBF using DVB and 4DTV receivers, the 4DTV receiver must be told to virtually "Rotate 90" the LNBF's polarity, it will then match a DVB polarity.
In other words, the 4DTV Horizontal is Vertical in DVB units. I don't know why, but I know it works that way.
 
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Ironsides

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Thanks Lak

Setting up an LNBf wouldn't be a problem for the FTA receivers I have; sadly though an older C-Band lnb has to use a servo. I wish I could upgrade that without a lot of change or expense to my C-Band. But I am afraid it would require more than just an LNB.

I have seen some of those cheap replacement Feedhorns that supposedly do both KU and C-Band but I was a bit afraid of them...

I have a nice 10 foot dish that is mesh but I was told when I purchased it many moons ago that it was easily converted to KU but changing the Feedhorn and adding a KU Lnb.

I never really checked into that...
 
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