DP-34 switch with bandstacked LNBFs

[Anole]

Dang it, Ice! Ya threw out the baby with the bathwater! -
We had this great off-topic discussion started in the middle of what turned out to be a hacker thread!
Darned good thing I kept a copy, huh?

Using a Dish Network DP-34 Switch for FTA

First, the switch is a big heavy monster, with tons of F connectors.
Built like a brick ... out house.
Could probably drive over it with your car and not hurt it!

Has three inputs, four outputs, and can be cascaded with a 2nd unit for 8 outputs.
Possibly to as many as 12 outputs, total.
Dish folks throw them away ! -

Cadsulfide documented how he was using it in an unusual way, and I wanted to preserve that idea.
I think he used it as a heavy-duty 3-in, 1-out diseqc.
Here's how the discussion went:

Try a DP34, bulletproof 3 lnb in 4 recievers out. Only need to use one lnb.

but that only works with stacked LNB's

But the DP34's work with the QPH031 right?

nope..the QPH is not stacked...very few KU LNB"s are stacked

I guess the big question is do you know what youi want to do in your head?
Then we might be able to give better answers

Ice,

I have a BSC421 C Band on Port 1, a DN FSS linear on port 2 (123), and a red 0.2 db linear on port 3 (125) of one of my DP34's and two generic linear lnbs and a Norsat lnb on the other. I get all the transponders and both polarities on both DP34's with no problems.

Do you have more than one receiver connected to any of your DP34's?

The DP-34 is just a big diseqc switch (with amps, and more)...
But in its normal configuration, all the receivers supply around 19 or 20 volts to the switch.
I was under the impression it was intended to operate only at the higher voltage.
But it's not like anyone publishes a spec sheet on it.!

If any of the connected receivers supply 18 volts for Horizontal polarity, that might propagate to all inputs.
It certainly should.
Likewise, I believe all LNBs are powered 100% of the time.
That's a big load on most DVB receivers.

I haven't taken a DP34 apart nor tested it outside its normal operating parameters.
You apparently have.
I wonder what loophole you have found . . .

 

[Mr Tony]

It would seem stupid to pick and choose what posts to delete in that thread since the hacker posts were mixed (making it harder to read and follow along) in so its easier to nuke the whole thread.

 

[Anole]

no sweat

Yea, that's why I kept a copy.
Just because the comments by old Cadsulfide were so thought-provoking!
Maybe we can carry the discussion to some sort of unimagined new solution.
Haven't had a brain-teaser like that in a good long while! - :up

 

[Tron]

I don't need to remind anyone that I'm a big fan of bandstacked LNBs It's like having an orthomode feed, but much simpler...

The DP34s seem to be built to take abuse, unlike the cheapy DiSEqC switches that we're often stuck using. Does anyone have experience using the DP44 (or higher model) switches with FTA gear?

 

[Cadsulfide]

Anole;

Glad you kept the thread.

Ice, thanks for nuking the hacker talk.

I will try the DP34 with two recievers and report back if it passes 18V to all three ports.

When I first set up my array I had one laying in the junk box. I just hooked it up without thinking about the bandstacked issue, and it worked. So I guess I stumbled onto a non-standard use for it. No genius here, just dumb luck.

A plus is that you can hang a meter on the pass thru ports to reaim a dish without powering down the system.

Another is since it powers all three lnbs all the time, you gain a little stability.
Your reciever needs a 500 ma drive capacity on the IF port to keep all that stuff heated up.

I suppose a DP44 would behave the same way. The required power inserter on port 1 adds an extra part to the mix, but should work with a lower powered reciever. An interesting experiment to try if anyone out there has a DP44.

 

[gillham]

I picked up a superdish 121, dish receiver and a DP34 recently, hoping to test the superdish out as a inexpensive FTA dish. They are sometimes available for $35-$45 locally and a used Coolsat 5000 or 6000 can be had for $30. Cheap FTA setup for a friend if it works out ok.

Anyway, the DP34 is built like a M1 Abrams. Makes my other 3x4 switches feel cheap. After testing this out a bit I wish I had some more band stacked linear LNBs. One isn't quite enough. It would be good to document the voltage behavior of the switch to know if more than one receiver can use the switch with a non DP band stacked LNB. E.g. if receiver 1 is using LNB 1 @18V, and receiver 2 wants to use LNB 2 @ 13V what voltage is coming out of each port?

I guess I need to get the multi-meter out and setup a test to answer my question. Also the DP34 does DiSEqC 2.0 with the DP LNBs, so maybe if there is a non DP LNB it behaves differently. Will have to check it out.

 

[Anole]

too many solutions

I have too many spare LNBs and too many spare switches, and way too many ideas!

Long time ago, I though if I could live with two or three bandstacked LNBs, then the DP34 would be my baby. - :up
But back then, I didn't have Dish FSS LNBs around.
Over time, I've collected some Eagle Aspens with the tall feedhorn, and some from 105° SuperDishes with round feedhorns.
(The SuperDish 121° has a tiny oval feedhorn, and I was always a bit shy of those)
Now, I even have a C-band LNBf that's bandstacked, which really could be the basis of a sweet system!
( ... if I just had a BUD ! )

Doing the Switches Simplified FAQ, we concentrated on non-bandstacked LNB support, and I guess I lost focus on the idea.
Also, the DP34 is limited to three LNBs for input, so that cramps my style a bit.
But, thanks to renewed interest, I've already come up with ways to integrated a motor, and expand to at least six LNBs!

Let's see what other ideas everyone comes up with.


Oh, and as for the DPP-44 switch, it's got four inputs and four outputs.
I tried to snag one a while back, but being newer, they weren't really available cheaply.

 

[Mr Tony]

the DPP44 is powered too

 

[gillham]

Ok, I happen to be working from home today so during lunch I plugged in a DP Dish 500 and DP34 with the DP311 receiver powering it. 17.5V on the 3rd (unused initially) port the whole time. I hooked up my meter and selected DiSEqC 3 which should connect me to the 3rd port. With the meter trying to find a vertical transponder I was getting still getting 17.5V. The DP311 was watching NASA on LNB 1 or 2. So with an 18V feed all ports appear to be getting 18V.

Then I tried powering with just the meter on vertical. Getting about 10.5V on the 3rd port. Horizontal I got "excess current draw" so the meter couldn't handle the whole rig. As expected I guess. I plugged in a Viewsat VS Pro tuned to a random vertical and still the meter got the excess power message when trying to test horizontal. Then it started to rain so I got back to work.

I'm charging the meter as the battery was a bit low and I'll test it later after I signoff work.

From what I can tell initially whatever the highest voltage is, that is what is fed to the LNB ports when you have multiple receivers. Though my meter may not be the best test, so I will try the DP311 & FTA later as well, when I can run a 2nd coax, or just take the stuff out by the tripod.

So I think the DP34 will work well for one receiver with any kind of LNB and only with band stacked LNBs with multiple receivers. Unless they were all on the same polarity and not Dish equipment passing 18V fulltime.

So it works as a more reliable DiSEqC I guess for normal LNBs. But with only 3 ports it is probably a waste for that strictly. Combining band stacked and normal is good for one receiver and if you're all band-stacked it is great for up to 4 receivers. And expandable to 12 according to some Dish PDF I found.

So in the most useful, all band-stacked setup, the DP34 is great, but having one more port will make the DPP44 interesting when they get cheaper. (If?)

 

[Cadsulfide]

ebay lists dp44's starting around $50, pretty spendy.

 

[Tron]

Pretty spendy is right... Looks like $50 would be a good deal for one, as most are going for $75-$90. Waaay too much for a switch, even such a nice one

I assume the power injector connects to any one of the outputs of the switch?

 

[Corrado]

I find this interesting as well. I learn new things everyday here. Please excuse my bandstacked inexperience.

I wonder why the DP34 is designed to power all 3 ports full time. I'm guessing so that multiple receivers could be viewing different sats at the same time.

I thinking about connecting another FTA receiver through such a switch. Would a second receiver help with the current load? Some boxes like my 9200 run warm as it is.

On the other hand, would it be better to switch off the LNBF power on the second receiver? Some models have that selection in the setup menu.

 

[Cadsulfide]

Pretty spendy is right... Looks like $50 would be a good deal for one, as most are going for $75-$90. Waaay too much for a switch, even such a nice one

I assume the power injector connects to any one of the outputs of the switch?

Tron

The book on it says the power inserter must be connected to port 1

 

[Anole]

some DP-34 brainstorming

Cost -
The DPP-44 only gives ya one extra input, so for the price, it's out of the competition.

On the other hand, venerable DP-34's can be had for $20,
...I've paid $10 used at swap meets,
... or free from neighbors, and out of the trash.

Power -
If you can afford to give up one output, then connecting a surplus Dish Network receiver gives you all the power you'd need.
If you get a DP-34 and model 301 receiver at a yard sale for $10 or $20, that could be quite attractive.

I would prefer to steer clear of home-made power inserters right now.
However, I do believe if they become a necessity, we can come up with something easy, cheap, and using pre-made parts.

Motors -
Though the focus was primarily on fixed dishes, I've wondered about how to power a diseqc motor.
At first, I thought about hanging the motor out between the switch and LNB.
If you can get the diseqc commands through the switch, it might be possible to take control of the motor by any of the receivers, if the others were turned off.

Without tests to see if the DP-34 could handle all the LNBs -and- the motor, I've also come up with a different way to place the motor between the primary receiver and switch.
That is more likely to succeed.

Fixed dish hookups will fill the bill for many, so I see no hurry to explore motors just now.

 

[lumpkin666]

Anole, I have nothing to add concerning actual usage of the DP34 (I had 2 back when I was a subscriber, but gave them away long ago). However, I agree, they are built like a tank. I dropped one from the top of a 2 story house - it landed on concrete and then a power drill landed on top of it. Other than a scuff from the concrete, it was fine and worked for the rest of the time it was needed.

 

[Anole]

Lumpkin -

Great story ! - :up
I would feel quite comfortable driving my car over one, and betting $20 on its survival.
Just don't drop a DP-34 on your foot, it could cause serious harm!

I was used to playing with those from hooking up my own Dish equipment some years ago.
And from eventually redesigning it, adding wing dish 'n switch, converting from Legacy to DishPro (to bandstacked), et al.
Even subscribed to BEV for a couple of years.

It wasn't until I joined the FTA forum here, that I'd ever heard of blowing up a diseqc switch by connecting it while powered.
Ya do that all day with the DP-34's, and think nothing about it!

 

[Anole]

more DP-34: Configurations


Configurations -
This isn't the first time I've thought about using DP-34's and I have sketched up several different configurations for them.

3 in, 3 out (all bandstacked)
Parts list: 1x DP-34 switch, 3x bandstacked LNBs, 3x FTA receivers

This is the simple and obvious setup.
Any receiver can get either polarity from any of three LNBs, all of which are constantly powered and stable.
I have a C-band LNBf that's bandstacked, and by combining it with one or two Ku bandstacked LNBs, a fellow could have quite the system.

The fourth switch output is reserved.
- In the future, we might find that a fourth FTA receiver is possible.
- Or, we may find that we need to connect a decommissioned Dish receiver to power the array.
- simple home-brew power inserter may be possible, but using one -and- connecting a fourth receiver is not being considered due to needing more research to assure safety and operability.

6 in, 3 out (all bandstacked)
Parts list: 2x DP-34's, 6x bandstacked LNBs, 3x FTA receivers, 3x 22khz eCoda switches

This is the next step in expansion. It's fairly simple and obvious.
Any receiver can get either polarity from any of six LNBs, using diseqc switch 1..3, and 22khz on/off.
Not a challenge for setting up any receiver.
All LNBs are constantly powered and stable.

The question here is passing power from receivers through 22khz switches to the DP-34's.
How do the DP-34's react if they lose power by all 22khz switches selecting one DP-34?
Maybe now, we need to consider that fourth switch output as a place to insert power, relieving the receivers and 22khz switches of the burden. (?)

Bears a striking resemblance to this design in the Switch FAQ.
But, substituting the DP-34 lets you use more than one receiver.


I'm pretty comfortable with the two ideas above.
They seem reasonalbe from a technical consideration, and provide considerable switching flexability.
Of course, they do need some experimental tests to confirm their reliability.

7 in, 3 out (3 bandstacked LNBs, 4 dual-output legacy LNBs)
Parts list: 1x DP-34 switch, 3x 22khz eCoda switches, 4x 4x1 diseqc switches, 4x 2x4 multiswitches, 4x dual output Standard or DBS LNBs, 3x bandstacked LNBs.

Looking to integrate regular LNBs, I sketched up this design using 7 LNBs, of which three were bandstacked, and the other four were traditional (Legacy) dual-output models.
It required four 2x4 multiswitches, four 4x1 diseqc switches, three 22khz eCoda switches, and a DP-34.
Due to the high cost of dual-output LNBs, and the need for one 2x4 multiswitch per LNB, I cannot really see it as a serious contender.
(...and ya cannot use 4x4 multiswitches...)


Well, those are some possible switch configurations.
I think they are attractive and useful designs for those willing to embrace the bandstacked lifestyle. -

 

[Cadsulfide]

By Anole
(6 in, 3 out (all bandstacked)
Parts list: 2x DP-34's, 6x bandstacked LNBs, 3x FTA receivers, 3x 22khz eCoda switches)

Now you have my juices going, I have each of my recievers modulated to a different TV channel, with a 6 in 1 out configuration I could eliminate a reciever.......Thanks!

Does anyone know if the DP34 provides any additional gain to the IF signal?

 

[Anole]

food for thought

I gotta think all that hardware inside the brick does something!
You can bet it doesn't have any loss.

Anole;
A plus is that you can hang a meter on the pass thru ports to re-aim a dish without powering down the system.

I was thinking how convenient that would be, but mostly for DBS use.
Might work for lower powered FSS satellites; I've used my old meter to find some.

Another use might be for guys wanting to hook up their professional sat meters.
Or the roll-out stand some guys (linuxman for one) have.
The fellows with spectrum analyzers might find those ports useful, too.

With the right switch, you might even add one more receiver.
Certainly you could feed two of the signals to a receiver with a 22khz switch.
That would get ya two of your three birds, and that might be fine for the kids.

Probably wouldn't make economic sense to get an uncommitted diseqc switch for all three passthroughs (or from all six LNBs of two DP-34's...) , but that's something to explore. . .

 

[Cadsulfide]

The pass through ports are great when you forget what dish goes where, the pass your hand over the lnb trick while the meter is on tone quickly reminds me of where I put it. To expand on your idea it could be used to select which birds the kids get.