[kuhawksr1]

Hi all ... what a great resource you all are. Very much appreciated. I've had three different D* installers walk in my home in the last 12 months only to leave shortly thereafter realizing that 1) they couldn't help me and 2) I knew a LOT more about this stuff than they did. Thanks to you all, I was well equipped. I'm getting ready to take a fourth run at it but this time I'm going to do most of the leg work myself (ordering equip I know D* will never provide an existing customer) but let the installer hook it all up. Now, on to my question.

I've read conflicting information. If you review a D* training manual (I stumbled across on the web), it states you can not diplex OTA with SWM, period. I know better on the SWM-8 module. I've read the DBSTalk first look of the SEM ODU LNB and it says, while D* doesn't recommend some testers have tried to diplex OTA with success. I think I have even seen example install diagrams of the SWMLNB with diplexers included.

Can anyone validate that diplexing OTA on a line from the SWMLNB will work? If so, are there any specific diplexers that must be used?

My system is about 5 years old and I know I'm going to have to replace my receivers (1 HDDVR, 1 HD, 2 SD) to be compatible with SWM. It is time for new receivers! I also know I'm going to have to hunt for a HR20-700 OR try the new OTA module for the HR21. I live in tornado alley and simply can not be without a signal when the clouds are thick. Consequently, I require OTA and am not willing to run more lines (would mess up the video distribution system I have behind my two SD receivers).

Any validation on diplexing OTA with SWMLNB line would be appreciated along with any specifics re: diplexers to use. Many thanks!

Ern

 

[Teronzhul]

It can work, as like you said, several on this board have successfully diplexed ota with an integrated lnb swm. The trick is that most diplexers are not designed to pass the 2.3mhz control signal on the satellite leg of the diplexer. Because of this, DirecTV finds it easier to just say that it doesn't work, rather than try to support something that many will likely have trouble with.

The only tricky part is finding diplexers that do pass the 2.3mzh signal well enough for the system to work, whether the diplexers in question were designed to do so or not.

 

[veryoldschool]

I think you do have a good grasp if the issues.
DirecTV does not "support" diplexing OTA with SWM.
By the nature of a diplexer [directing low frequencies to one port and high frequencies to another] they're not really SWM compatible.
While the SWM channels work fine, since they're above OTA, what is the problem is the 2.3 MHz SWM comm signal, used to communicate between the SWM and the receivers.
Diplexers do pass DC and the 22 KHz tone to the SAT leg. "The problem is": how much loss is there at 2.3 MHz? If it's too great [going through 2 diplexers] then the SWM/receivers lose the "comm" and won't work.
I'd re-visit those setup diagrams and see what diplexers have been used, to get a idea of what "has worked".

 

[bakers12]

I've got diplexers all over my SWMLine setup with no problems. I'm using a Channel Master 4002IFD for combining the OTA into the line and 4001IFD's for splitting it out.

Follow the link in my signature for more details.

 

[1948GG]

If you review a D* training manual (I stumbled across on the web), it states you can not diplex OTA with SWM, period. I know better on the SWM-8 module

As do those who design and build MDU systems. I'd sure like a link to this 'training manual', might make interesting reading.

ALL of my MDU systems (using the SWM8) integrate OTA, utilizing commercially available diplexers. I keep reading (on sites like this) of folks that have had problems, but it's so few and far between that I've been unable to obtain a 'sample' of a 'bad' diplexer. I guess I'll keep looking.

BTW, I've tested the OTA integration using both the SWM8 internal adder (the OTA integrator built into the SWM8), AND integrating it outboard with another diplexer 'in the line' in the SWM8 output, although all of the operating systems use the internal SWM8 adder.

The only real 'trick' is to properly feed the OTA signal at a good level into the SWM8. For something like the SWMLNB (which I take it does not have an input for OTA, so one has to add the signal into the line at some point downstream), the basics of RF levels still come into play. The signal (raw) off the antenna or antenna array may need some amplification before insertion.

Added NOTE: All the electronics, the power feed (if any) to the amplified OTA antenna, need to be SEPARATE from the satellite feed system. That's obvious to me straight away, but I've seen folks here that don't understand that one can't 'mix and match' systems together like that.

Hook the OTA system directly to the DirecTV receiver first, and verify the operation and stations received. Then hook the feed into the diplexer system (an 'insertion' module and an 'extraction' module) and retest for signals. Like I said, you may have to level the RF input to the system to get the performance back up to what you had with the 'straight' system.

If your OTA antenna is amplified, particularly with a system where the gain is adjustable, you'll probably be able to get excellent results. But it all depends on the level and quality of the signal in the first place (which is why you need to 'baseline' the system beforehand, as noted above, with a line straight to the receiver from the OTA antenna).

Sounds complicated, but isn't. Again, I simply haven't run into any 'bad' diplexers as of yet. Kind of like all the reports of 'bad' BBC's. I'm still looking. Meanwhile, folks here have already chimed in with what they're using, and so will I:

Perfect Vision PVDP3. No problems, very cheap.

 

[veryoldschool]

As do those who design and build MDU systems. I'd sure like a link to this 'training manual', might make interesting reading.

http://forums.directv.com/pe/Reposi...96641/SWM - Integrated LNB-ModuleTraining.pdf

 

[thestaton]

I just setup my OTA through the SWM8. Ran the OTA right to the port on the SWM8. Then put diplexers on the end of the cables that ran into the house, connected one end to the AM-21, and the other end to the HR-21's. Works great.

The only problem I found is I lost some where around 25% signal strength. Other than that everything works great.

Just don't make it harder than it has to be.

 

[hancox]

I've got diplexers all over my SWMLine setup with no problems. I'm using a Channel Master 4002IFD for combining the OTA into the line and 4001IFD's for splitting it out.

Follow the link in my signature for more details.

Same here. Don't let the naysayers drown you out. Works great.

 

[texasbrit]

I also have been using diplexing since I got my SWM (during the field trials). I use the SWM internal diplexer and then distribute the signal to four different recivers/DVRs. I have never had a problem.
As 1948GG says, you just have to remember basic RF issues when it comes to OTA. If you use the internal SWM diplexer that gives you less than 50% of the signal on each SWM output. Put another splitter in an output line that's another 50%+ reduction in signal strength. Then the diplexers themselves give you signal loss. So if you have a weak signal going on, you will have a very poor signal at each of the receivers.

 

[kuhawksr1]

Sensational feedback. Thank you all VERY much for taking the time to respond and doing so quickly. I'm going to give it a shot and may reply with an update on results.

 

[1948GG]

http://forums.directv.com/pe/Reposi...96641/SWM - Integrated LNB-ModuleTraining.pdf

Thanks, I needed a really good laugh today! There are literally errors aplenty in this document, that contradict several other 'correct' DirecTV documents, IF this is in fact a product of DirecTV document control, which, as it doesn't have any legal markings (or document control numbers) on it, I greatly doubt.

Probably produced (and distributed) by one of the myriad 3rd party companies trying to do business with DirecTV.

 

[veryoldschool]

Thanks, I needed a really good laugh today! There are literally errors aplenty in this document, that contradict several other 'correct' DirecTV documents, IF this is in fact a product of DirecTV document control, which, as it doesn't have any legal markings (or document control numbers) on it, I greatly doubt.

Probably produced (and distributed) by one of the myriad 3rd party companies trying to do business with DirecTV.

The front page shows: "Field Operations Training April 2008 Version 2.1"
I got a copy from an installer here, which makes me think this is/was direct from DirecTV.

 

[kuhawksr1]

Thanks again for all the great advice here!! The plan worked perfectly. Although I'm told that using SWMline LNBs (5lnb with SWM built in) will be standard sometime next year for upgrading existing customers, I was impatient and found one online for under 80 bucks. I then placed the call to D* and asked them to upgrade my HD equipment for free. They did. When the installer arrived, I asked if he would be willing to use the SWMLine LNB I had purchased online instead of the non-SWM LNB he brought with him. He said no problem (and even left me the non-SWM LNB to use for tailgating). He installed a new slimline dish, used my LNB, brought a new HDDVR and HD receiver and hooked it all up. After he left, I installed the Channel Master diplexers referenced above and everything is working perfectly!!! I'm running D* receivers to TV(s) using component/composite cables and have OTA coax running to the TV(s) as well. I love the expanded HD selection and the RF remotes work better than my old ones ... much greater distance.

Thanks to all the advice received here, I was able to make the upgrade and not lose a thing!! Thanks again.