Diode Steered Hi Frequency Splitters - 102

[linuxman]

I have some DC block power pass only on one side Hi-Freq splitters that I have always used with analog/4DTV boxes with DVB receivers slaved to them and have had no problems.

I also have some "diode steered" Hi-Frequency splitters that I have been using for a few months between DVB receivers of various kinds. I have not had any problems with these either.

Can you use the "diode steered" Hi-Freq splitters with analog/4DTV and DVB receivers in the same way?

By the same way, I mean with both the Analog/4DTV and the DVB receiver on at the same time without blowing something up?

And just for the sake of my knowledge, can someone explain how these "diode steered" splitters work?

Thanks!

 

[USDownlink]

I'll give it a shot since it's been around for a few hours with no other takers. Short answer is yes, you can use the diode splitter. For details, read on.

I have some DC block power pass only on one side Hi-Freq splitters that I have always used with analog/4DTV boxes with DVB receivers slaved to them and have had no problems.

I presume this is a consequence of convenience or necessity to the installation? As in the 4DTV box needs to drive an actuator, or something of the sort? [I know my 4DTV box does not have a "loop out" port, which would be preferred in order to avoid the signal loss of a splitter. I'm just curious for personal reference; I am not questioning the setup - I've done much worse things to satellite signals to claim the moral authority ]

I also have some "diode steered" Hi-Frequency splitters ... between DVB receivers of various kinds. I have not had any problems with these either. ... can someone explain how these "diode steered" splitters work?

I don't own any diode steered splitters, as I have no application which requires them. I have looked into them in the past, however, and feel I have a good understanding of them. (Diode steering is a concept applicable in many other areas of electronics, and this is a rather straightforward usage). In the absence of anybody offering personal experience, I'll suggest the following demonstration which should address your concerns: Between two of your DVB receivers hooked to a diode steered splitter, set one receiver to a horizontal TP and the other receiver to a vertical TP. You will find that the receiver with the vertical polarity isn't working, yet nothing is blowing up. This is the nature of diode steering - it lets the higher voltage (of horizontal) dominate, and prevents the the higher voltage from entering (and damaging) the receiver tuned to a vertical TP.

So now,

Can you use the "diode steered" Hi-Freq splitters with analog/4DTV and DVB receivers in the same way? ... with both the Analog/4DTV and the DVB receiver on at the same time without blowing something up?

You will be perfectly fine using the splitters between any receivers, analog, DVB, 4DTV, or otherwise. No DC voltage will be back fed into any receiver, but all receivers will be able to see the signal coming from the LNB, as instructed by the "dominant" (highest) receiver voltage.

 

[linuxman]

I'll give it a shot since it's been around for a few hours with no other takers. Short answer is yes, you can use the diode splitter. For details, read on.

I presume this is a consequence of convenience or necessity to the installation? As in the 4DTV box needs to drive an actuator, or something of the sort? [I know my 4DTV box does not have a "loop out" port, which would be preferred in order to avoid the signal loss of a splitter. I'm just curious for personal reference; I am not questioning the setup - I've done much worse things to satellite signals to claim the moral authority ]

For this particular setup, I have a single dish and want both receivers to have control of power to the LNB whether the other receiver is on or not. With the DC block splitters, the receiver assigned to the power pass side must be on to get power to the LNB and in most cases, if changing from C-Band to Ku, the master receiver has to be changed in order to get power there.

I don't own any diode steered splitters, as I have no application which requires them. I have looked into them in the past, however, and feel I have a good understanding of them. (Diode steering is a concept applicable in many other areas of electronics, and this is a rather straightforward usage). In the absence of anybody offering personal experience, I'll suggest the following demonstration which should address your concerns: Between two of your DVB receivers hooked to a diode steered splitter, set one receiver to a horizontal TP and the other receiver to a vertical TP. You will find that the receiver with the vertical polarity isn't working, yet nothing is blowing up. This is the nature of diode steering - it lets the higher voltage (of horizontal) dominate, and prevents the the higher voltage from entering (and damaging) the receiver tuned to a vertical TP.

So now,

You will be perfectly fine using the splitters between any receivers, analog, DVB, 4DTV, or otherwise. No DC voltage will be back fed into any receiver, but all receivers will be able to see the signal coming from the LNB, as instructed by the "dominant" (highest) receiver voltage.

Thank you for the lucid explanation of how they work. I now have a better understanding and am confident that I won't blow anything up by using them.

 

[tvropro]

A diode allows voltage to flow one way and not the other. That may help this be understood better.

 

[Tron]

I've never seen diode-steered splitters, only one port power passing and all port power passing. Linuxman, I'd like to try a diode steering splitter... Do you have a link to the ones you're using?

 

[voomvoom]

I've never seen diode-steered splitters, only one port power passing and all port power passing. Linuxman, I'd like to try a diode steering splitter... Do you have a link to the ones you're using?

I'll second this question.... Fred where are you? We have inquiring minds, and we want to know?

 

[truckracer]

diode splitters

You will not harm anything by feeding voltage from two receivers at the same time (if it happens) to one lnb or lnbf. I have done it for years with no problems.

Keep in mind that if multiple receivers are sending voltage to a coax here is a list of some possibilities and results:

Receiver 1- 13V + Receiver 2 - 13V = 13V (they are sending voltage in parallel not increasing the voltage but potentially increasing the available current.
Available current does not matter since the lnb or lnbf only draws what it needs.


(same as above with 18V for Horizontal)

Now If:

Receiver 1 - sends 13V while Receiver 2 - sends 18V your total output will be the higher voltage = 18V. So in this case only the Horizontal tp's will be chosen with no damage to the 13V receiver or lnb.

If you are using a corotor or other feedhorn that is servo controllled, any voltage does not matter as all receiver will see the same polarity. However depending on what polarity you are calling for on each box will depend (for display purposes) which polarity is indicated on the screen during a scan.

If your receiver thinks it is scanning Horizontal tp's but your feedhorn is turned to Verticals, all the verticals will appear as H on the screen but you will still get everthing. Also Vice versa the other way.


It will works so don't worry.

 

[linuxman]

Sorry, since I posted this morning, I have been outside working on my latest project. More on that elsewhere.

Thanks tvropro and truckracer, it is starting to sink in.

You will not harm anything by feeding voltage from two receivers at the same time (if it happens) to one lnb or lnbf. I have done it for years with no problems.

Keep in mind that if multiple receivers are sending voltage to a coax here is a list of some possibilities and results:

Receiver 1- 13V + Receiver 2 - 13V = 13V (they are sending voltage in parallel not increasing the voltage but potentially increasing the available current.
Available current does not matter since the lnb or lnbf only draws what it needs.


(same as above with 18V for Horizontal)

Now If:

Receiver 1 - sends 13V while Receiver 2 - sends 18V your total output will be the higher voltage = 18V. So in this case only the Horizontal tp's will be chosen with no damage to the 13V receiver or lnb.

If you are using a corotor or other feedhorn that is servo controllled, any voltage does not matter as all receiver will see the same polarity. However depending on what polarity you are calling for on each box will depend (for display purposes) which polarity is indicated on the screen during a scan.

If your receiver thinks it is scanning Horizontal tp's but your feedhorn is turned to Verticals, all the verticals will appear as H on the screen but you will still get everthing. Also Vice versa the other way.


It will works so don't worry.

I am using a Co-Rotor, so voltage is what I want, and I have a polarity switcher to bounce back and forth between the 4DTV and the Pansat 2500a receiver.

I just wanted to verify that I wouldn't burn anything up.

This whole thing goes back to when I first started and did have my Pansat 3500 slaved to an analog receiver. That's when I made the polarity switch, but still had the problem of having to make sure the analog was turned on for C or Ku or no power to the LNB.

If you remember, I burned up a series of diseqc switches during the first two weeks of operation. The reason for that was detailed in the thread I wrote at the time, but it was because I was using power passing on both sides Hi-Freq splitters with no block of any kind.

So I quickly learned that I wanted a DC block on one leg to keep that from happening again. All was well for over a year, and I inquired from the last place I got the DC blocked splitters, and he said that they were no longer being made by his supplier. Everything was going to "diode steered" splitters.

So I bought a 4-way and two 2-way "diode steered" splitters from him. I have been using the 4 way with my Diamond 9000/Twinhan 1020a/Coolsat setup and it all works fine and since I only keep one of them on at a time, I have never had a problem with any of it.

But now that I wanted to try this 4DTV/Pansat 2500 setup, my fears all came back and I wanted to verify that all would be well in an analog/dvb setup.

As to where I got mine, I got them at my local supplier and they don't have a public website.

Sadoun has some on ebay with a description if you scroll down, so I know he carries them.

If you have bought a Hi-Freq splitter in the past few months and didn't specifically ask for power passing on one port only, you probably already own one.

 

[voomvoom]

If I wasn't already confused (I'm sure I was, I always am), I am now for sure. I followed your link to Sadoun and see this:
#

All ports Diode Protected DC power passing

We've now graduated from Diode Steered to Diode Protected
Which is it, and just how does it work?

 

[linuxman]

If I wasn't already confused (I'm sure I was, I always am), I am now for sure. I followed your link to Sadoun and see this:
#

All ports Diode Protected DC power passing

We've now graduated from Diode Steered to Diode Protected
Which is it, and just how does it work?

Hey Al,

I think they are the same, just different wording which is confusing at least to me.

As for how they work, I only know what has been written above by Truckracer, Tvropro, and USDownlink.

They can explain it much better than I can. I know I like the setup I have currently with my Diamond 9000/Twinhan 1020a/Coolsat setup. Don't have to worry about leaving one on accidently, and all three receiver have complete control of the G-Box and the LNBFs when they are turned on.

 

[Larry1]

The dollar store by me has a 2 port power passing HF splitter for $2.00. It is diode steering. Has a diode from each of the two outputs passing power to the input. The diode prevents the power from one output to flow to the other output. The power can only flow from the output to the input. For illustration purposes, think of the diode as being a one way street. For the splitter, two merging oneway streets.