<lj-cut text="Likely to be eaten by a Grue --More--( 5%) "> I have these objects:
D575D destacker
PAL30 DBS amplifier; HRFPI power inserter
uS575 stacker
With this:
- Single LNB → 1 very long coax run from roof →
DirecTivo
I have only a single LNB, but I get 90% signal on even and odd transponders. Either LNB works. With this:
- Dual LNB → 2 short coax →
uS575 Stacker → 1 very long coax run from roof →
HR PI 10-2150 MHz Power Inserter → 1 short coax →
D575D Destacker → 2 short coax →
DirecTivo
I get 90% signal on odd transponders and 40% signal on even transponders, which is not enough for DirecTivo to be happy. Without the power inserter, this configuration doesn't work at all (indicating that the stacker requires additional power beyond what the DirecTivo provides.) With this:
- Dual LNB → 2 short coax →
uS575 Stacker → 1 short coax →
PAL30 DBS Amp → 1 very long coax run from roof →
HR PI 10-2150 MHz Power Inserter → 1 short coax →
D575D Destacker → 2 short coax →
DirecTivo
I get nothing. But maybe I have it hooked up wrong. Note that this amp has 3 coax ports on it, labelled "DBS Input", "In/Out DC" and "DBS Output". The old one had that too, but was not necessarily the same model amp. My best guess is that "DBS Input" connects to the stacker (and thence the LNBs), and "DBS Output" goes to the long run (and thence the power inserter, followed by the destacker, followed by DirecTivo).
I think I've tried all the other permutations too. No luck. What inputs on that amp am I intended to use?
If the amp goes before the stacker, and does not pass that +20v through to it, how can the stacker work? How did it ever work before? Because it did.
At this point the only components I have not replaced are the destacker and the DirecTivo itself. The fact that the single-tuner configuration works seems to indicate that the DirecTivo is fine. I'm hoping to not have to replace the destacker as well. How could that have gone bad? It's inside!
(I now have 3 stackers, 3 power inserters, and 2 amps. One of each is old, and I've tried all of them at this point, though not in every possible permutation.)
Update: Finally! This worked:
- Dual LNB → 2 short coax →
uS575 Stacker → 1 very long coax run from roof →
PAL30 DBS Amp, powered directly → short coax →
D575D Destacker → 1 short coax →
DirecTivo
With that, I get 90% signal on even and odd transponders on both LNBs! Yay!
This is not how I had it hooked up before. Before, I did what I think everyone would say is the sensible thing and put the amplifier outside close to the signal source, instead of inside, after the long run had already degraded it. But, for whatever reason, that no longer works and this does. On the amp, "Input" goes toward the dish, "Output" goes toward the destacker, and "in/out" has the wall wart. The HRPI is unused.
I cannot explain why this works and the other way does not (but used to).
I think the 40%/90% signal strength is a consequence of stacking the signals; the signal from the even transponders is shifted up to a higher frequency range where the attenuation of coaxial cable is greater.
Getting nothing makes it likely some component is either dead or not receiving adequate power. It's possible your amplifier functions only when its power source is connected to the "IN/OUT DC" port.
You could put the amplifier inside, so the connection looks like:
This violates what I said before about the best place to put the amplifier, but it might be worth trying.
(I'll assume suggestions to pull more coaxial cable to the rooftop or use a spectrum analyzer are not helpful.)
Just to clarify, what I meant by "power inserter" above is really "power supply"; the amplifier is its own power inserter.
I'm starting to wonder about adequate power here too, particularly given the new equipment. Could some of it have higher draw than the old equipment, and be thereby exceeding the output capacity of your power inserter?
But, the current batch of gear I'm using -- the stacker, the amp, the power inserter -- I got by buying the STACKER-PKG here. They all came in the same box. So, you know, you'd assume they'd work together.
This is the same kit I bought the first time around, 5 years ago or whenever. Though this time the components look different (though the stacker has the same model number as before.)
Since the site you bought it from says to arrange the components like this:
Dual LNB → 2 short coax →
uS575 Stacker → 1 very long coax run from roof →
PAL30 DBS Amp → 1 short coax →
HR PI 10-2150 MHz Power Inserter → 1 short coax →
D575D Destacker → 2 short coax →
DirecTivo
I presume you've tried that? All the arrangements you've mentioned (except the one without the stacker) had the amp outside.
This picture seems to imply that the "In/Out DC" is actually your digital signal carrying cable down to the power inserter and then on down from there to the destacker. And that DBS Output is actually the input from your dish's stacked signal, and that DBS Input is some sort of antenna connection.
If so, this is a monstrous clusterfuck of labeling. (I mean, I can see what they were thinking: "Connect the DBS's output to here, connect the DC source to here" but come on people, what the hell?)
It would help very much if Sonora's website had the PAL30 documentation. Or had it listed. Or acknowledged it in any way.
I agree profusely. And sorry if my previous comments here were kind-of unhelpful, I completely missed that the LNBs had been replaced (and the coax attenuation when-stacked theory is probably as good or better than the 'new power inserter causing polarity-selection bias' theory).
That label really is a bit of a clusterfuck. Since it shows the AGC (gain control) on the "input" side, you'd really think the "input" would run to the dish and the "in/out" would run to the receiver+inserter. But if you look closely, that's not where the blocking diode is, so I guess you have your choice of "input" or "in/out" to the receiver+inserter, and "output" to the dish. Is it possible the wiring got rearranged when it was brought indoors?
The fact that it works well as such is probably a testament to how decent the electronics are, despite the poor instructions. And at least this way it's one less thing out in the weather.
And at least this way it's one less thing out in the weather.
Indeed. I still don't understand, but I'm declaring victory.
FWIW, my analysis above forgets that, if going dish-stacker-amp--power-IRD, you need to power the stacker, so would actually need to use the "input" and "DC" sides without the diode, if I got that right, to share the voltage with the stacker. Or "backwards", so the diode isn't preventing the voltage from being shared upstream.
The diode is a passive component (would've blocked power to the stacker with or without the inserter powered) so I don't think that was your actual failure mode.
Also, I've been assuming the inductors pictured are for matching, but if they're actually chokes (pass DC, block RF in/out) it'd be a miracle if any application trying to get RF off the DC port ever worked (like the one pictured in the MSPaint-type doodle above).
And finally, re-reviewing the diagrams, it could be that the HR PI inserter is defective(?) and similarly pessimistic to the stacked signal - either because it was attenuating (outright defect), or because it was picking up a lot of local noise (WiFi?) and cocking up the bit error rate. It'd take a painfully expensive meter to tell you whether the stacked signal was actually weak, or strong-but-dirty.
Power inserters are always built kind of cheaply, because they're such simple components; if the 'picking up noise' theory applied, just one wire of the wrong length could be acting as an antenna and ruining your day.
Ok, before I climb up to the roof again, I tried this:
Single LNB → 1 very long coax run from roof →
PAL30 DBS Amp, powered directly → short coax →
DirecTivo
Result: good signal on all transponders when the wall wart is unplugged (as if it wasn't there). But, applying power to the amp results in strong signal on even transponders, zero signal on odd transponders.
I think this is correct behavior. In a system with no stacker, the DC voltage from the IRD provides both power and information (one bit) to the LNB. Depending on the voltage (13 V or 18 V), the LNB sends either the odd or the even transponders down the line.
With the wall wart unplugged, the amplifier is being powered by your IRD (at whatever voltage) and it works (or at least passes RF and DC). When you connect the wall wart, you override the IRD's voltage output, so the LNB will see only a voltage instructing it to send even transponders, even if the IRD is wanting an odd transponder.
None of this should matter, since the stacker will provide both 13 V and 18 V outputs to the LNB once it is part of the system.
But wait, shouldn't the amp only be amplifying the downstream (toward the DirecTivo) leg, not the upstream (toward the LNB) leg? That's why the connectors are labelled "RF" and "RF+DC", right?
Also, I thought that "amplifying the downstream RF signal" and "increasing upstream DC voltage" were not the same thing?
That's right. It's not anything in the amplifier part of your amplifier that causes the DC voltage to change; the RF amplifier works in one direction only. Rather, it's the power inserter part of the amplifier that's passing the DC voltage from the amplifier power port (if greater than the voltage provided by the IRD) to the amplifier RF input port.
(Look closely at the inductor and diode symbols on the amplifier case.)
But, since using the single run gives 90% signal, you don't have that much loss, why not just have a second run put in, and do away with all the complicating factors?
If it was even remotely possible to have a second cable, I wouldn't have to fuck around with this stacker/destacker bullshit in the first place. It's not. Even remotely.
Silly question, no idea if it would even work... but twinax cable?
No. Just stop.
Yeah, his reply to me means that there's no way he can run more cable at all, of any kind. So, no. :(
My idea was really, pull a new cable with the existing cable. You get extra points for being lazy then :)
here's an idea: tie the top end together with a diode, and use a volt-ohm meter at the other end to see if the shield and tip inside has actual diode-like properties. Then climb up and reverse it. For more fun, make a relay-controlled diode-pair alternator on a breadboard first, but don't go nuts and try to do it with solid state, and don't climb the ladder with the thing buzzing.
more ritzy: use a sweep frequency circuit on the top end and an oscilloscope on your end. This will detect some forms of failing installation, but you need a good cable to use as a reference, and if it's coiled up instead of spread out then you better have low voltage or you'll get induction effects.
If the cable is bad, then you can think about the possibility that it might have had a powered-on weathering event, but that seems unlikely
As for the stuff you're plugging into it, I'd say go ask giantlaser, analog for me comes with shorter wires these days.
If you're going to go to that much trouble, wouldn't it be easier to rent a Site Master, or at least a good TDR?
Seriously, if the long coax will pass RF and DC well enough to give a 90% "signal strength" reading, it's probably fine.
Quite true, unless part of the 10% is in a frequency you are using for a carrier. Nice looking gear!
Have you just tried to use the stacker/destacker by themselves? If the single LNB solution works at 90%, it then seems reasonable to think that you wouldn't need the boost with the multiplexed signal.
Stacker + destacker + no power inserter = 0%.
Stacker + destacker + power inserter = 90% on even but 40% on odd.