SWM Setup with Amplifiers

[tailgateco]

Hey folks. I've posted on here before about this setup. I've started to have some slight problems with it and wanted to get some input.

The setup: Attached is a schematic of what I have. I do tailgating. Everything is outside and the setup is pretty ridged so if possible, I'd rather not relocate any element in the system other than the possible locations for amplifiers. I show just one line coming off of the SWM 16 to 6 receivers. I do use both lines. Each "drop" to a receiver is a SWM splitter so there are 5 splits in the system.

The problem: 80% of the time, this setup works great. However, sometimes the TVs on the end will get temperamental. They will show lost signal for a few seconds and come back. Sometime they will go off for longer. If I go to the signal strength screen from my box it shows 0% signal from the satellites. Then it will randomly come back.

I'm guessing this is a signal degradation issue? I don't have any way to measure signal quality at the box other than going into the menu and checking satellite signal strength.

Two questions:

Assuming this is signal degradation,

1) Is there a signal strength meter I could buy that would tell me if I have signal strength issues? Would it tell me anything the box can't tell me?

2) Would either or both of the locations I have marked in the skematic as possible amplifier locations be advised? Are the models I mention the appropriate ones?


Thanks for any help you can give!!

 

[raoul5788]

Normally I would suggest using a swm lnb, but since you already have this setup....
What are your signal strengths? Have you tried the other output of the swm16?

 

[Jam3s]

How many tuners are you using? If only 6, see below. If more than 6, you need to use the second feed off of your SWM-16 because you are just competing for swm channels.

You don't want to amplify the feeds off of the LNB, odds are that your problem is on the cable from the splitter to the IRDs. My first question is, are you cascading splitters? If so, how. For example, 2-way in to a pair of 4-ways, 2-way in to another 2-way and a 4-way, etc.

If you're running everything off on an 8-way, I'd recommend not amplifying unless you have only one excessively long line (in which case, amplify that line). If you do amplify the 8-way, do it between the SWM-16 and the splitter. Reference below:

(shorter run) 4way - IRDs​

(Cascade Splitters) -> LNB - SWM Module - 2way<

Amplifier - 4way - IRDs​

(Single 8-way) -> LNB - SWM Module - Amplifier - Splitter - IRDs

Or some combination involving coming off of a 4-way in to two-way splitters with an amplifier in between for longer runs.

For your meter, you can pretty much use anything to align the dish as long as you make an attempt to dither it. If you need a meter for troubleshooting, about the only thing you can use is the AIM, which would be kinda overpriced and you probably need some training to understand how to TS why your signal isn't working.

 

[texasbrit]

I think I remember your original post on this, yes?
From the diagram, it's pretty clear what is going on, so most people's questions are in fact already answered. The line is being split five times, each splitter reduces the signal by 3db approx. The lotal loss at the last two receivers is 15db, plus the losses in the cables. I assume from the post that the other output from the SWM16 is split the same. An 8-way green label splitter has around a 14db loss at SWM frequencies (this is an actual measurement) so that says your issue is cable losses. What's the total length of the cable run from the SWM16 to the furthest receiver and what type of cable?

Amplifiers: You don't need an amplifier between the dish and the SWM16 because the SWM16 has Automatic Gain Control (AGC) which gives you the same output level regardless of the input level at any reasonable input level. But the SWMA2 will amplify the signal from the SWM16 and will almost certainly solve the problems on the run to the receivers. I have concerns about putting it where you suggest because it might increase the signal to the point of overload of the first receivers, just speculating about that because I don't know what the receivers can accept. You could try it and if a problem move it to just after the first splitter.

 

[raoul5788]

Silly me, I assumed he was using a sws8 splitter. Like texasbrit said, splitting the signal that many times is the problem. Shouldn't he just use a sws8?

 

[texasbrit]

he does not want to use an SWS8 because then he would have to run a separate cable from the multiswitch to every receiver. His five splitter config would be OK if the cables were all very short. So an amp on the line to the receivers is probably the easiest solution.

 

[raoul5788]

I went back and read his original post. I saw what he said about the cabling. Still, a sws8 would be a better solution, yes?

 

[texasbrit]

Yes it would, but it's a lot of cable, and if the longest runs are very long you might still need (maybe multiple) amps. I suspect the single amp is the best solution under the circumstances.

 

[twizt3dsist3r]

Yep I concur.. the problem is with dB drop.. the floor for dtv dB is -55 and each 2 way is actually closer to 4 dB since each fitting is .5. There is approx 1 dB loss for every 10 ft of rated cable. Not to mention a good guess for your dB straight off the swm16 is gonna be -25 to -30. Your looking at about -50 at the end of the chain not including cable length or temp and such.. amp it if you must daisy chain

 

[texasbrit]

Yep I concur.. the problem is with dB drop.. the floor for dtv dB is -55 and each 2 way is actually closer to 4 dB since each fitting is .5. There is approx 1 dB loss for every 10 ft of rated cable. Not to mention a good guess for your dB straight off the swm16 is gonna be -25 to -30. Your looking at about -50 at the end of the chain not including cable length or temp and such.. amp it if you must daisy chain

Yes, you are right, about 4db per splitter. For some reason I wrote 3db.
My other numbers are a bit different from yours but I have the same conclusion. Losses at the highest SWM frequency are a little less than you posted, just over 8db per 100ft, but still significant when you have very long runs. And yes, the SWM16 should give you about -30dbm at the output.
In theory the receiver needs a minimum of -65dbm. With -30dbm plus 25db losses in the splitters, that's -55 dbm. Not much to play with for cables!

 

[twizt3dsist3r]

-65 floor for functionality but dtv requires -55 to account for rain fade.... although I'd be surprised if half of the techs in my own office could follow this conversation. .. you really need to know your stuff to understand the functionality

 

[texasbrit]

Think the rainfade number is misleading. Signal attenuation due to rain droplets is massively larger than 10db, particularly at HD frequencies, so it won't buy you much - more useful at SD though. But every little bit counts.

 

[tailgateco]

Thank you all so much for your input! Sorry for the delayed reply. I'm not sure I can answer all the questions asked, but I'll do my best to clear up a couple of things.

I use the SWM 16 because I use one multi switch for 2 rows. I just didn't show that in sketch for simplicity. I revised the sketch and attached.

All the cables between splitters are 12 ft. It sounds like what I need to do is add the SWMA2 around the 3rd receiver?

I admittedly know nothing about this stuff, but I am an engineer by degree and a nerd at heart so I'm loving learning it.

Another possibility for the future that I had recommended by Sonora's tech support was to scrap the splitters, put in an amp at the beginning of the row and use taps at each location instead of splitters. Any thoughts on this?

 

[texasbrit]

Using taps instead of splitters won't help you with the losses issue, although it would help control signal overload when you use an amp. Taps are generally used in buildings to try to give equal signal to multiple receivers on a multidrop network like yours, but you still get 4db per drop.
Putting the amp at the beginning of the row might work OK, assuming it does not overload the first receiver, and I have no idea what the maximum input signal is for a DirecTv receiver. Putting it down the row would avoid that problem, or you could use a tap instead of a splitter for the first couple of receivers to increase the attenuation at the receiver.

 

[KenStomski]

there are "trunk" taps rated at 9,12, and 16 db, and "room" taps rated at 6,9,12,16, and 20 db. you could use an amp at the beginning of the line, and not worry about overload at the nearest receivers with the proper configuration... basically the same technology used in MDU and the new digital swm systems for daisy chained DRE properties.

 

[texasbrit]

Yes, that's what I mentioned. But if the OP can put the amp in the middle of the "trunk", and use splitters, that would be less expensive, since he already has the splitters...

 

[tailgateco]

Interesting, I was told taps have a lower (~1dB) loss on the main line and regulate down to the receivers. I guess I was told wrong!

For now, I'm going to play with placement of an inline amp. At $35 bucks a pop I think it's an ideal solution if it works.

I mentioned a signal meter....what's my best way to know how many dBs I have at a receiver? Can I get something that will tell me that?

 

[texasbrit]

My info says taps have the same loss at SWM frequencies as splitters on the main line, if you include the connectors. Even if it was slightly less it would not be enough to give you a reliable solution. Their main value is the attenuation they give to the "tapped" output which allows you to reduce the signal to ensure you don't overload the receivers close to the amplifier. In a building, you often can't put the amp in the middle so the first few receivers get a very strong signal unless you use taps (or attenuators).

As far as measurement is concerned, don't know exactly what you would need but it's not going to be cheap. A decent signal meter that will read the Hd signals is several hundred dollars.

 

[Claude Greiner]

If your going to run it like that daisy chained, then you need a digital SWM 13 switch along with taps, instead of splitters.

It's similar to loop through wiring you see in s hotel.

The reason why I saw swm 13 is because the output is very hot.

You can use a swm 8, but you need a separate feeder line back to the Dish

 

[texasbrit]

If your going to run it like that daisy chained, then you need a digital SWM 13 switch along with taps, instead of splitters.

It's similar to loop through wiring you see in s hotel.

The reason why I saw swm 13 is because the output is very hot.

You can use a swm 8, but you need a separate feeder line back to the Dish

No, you are overcomplicating this. The OP already has an SWM16 and is using both outputs. Using a "commercial" SWM13 (remember this isn't available to consumers, only to commercial installers) might give a higher signal level (I have not seen any numbers by the way) but it's not a better solution. Remember the OP already has the SWM16, and the splitters, and with the addition of an amp on both legs has a perfectly viable solution.