: Splitters, Attenuators, Filters, Diplexers, Other Signal Gear
2008-07-26, 05:52 PM
Basically you need a certain amount of gain for the tuner to lock on to a digital signal. Stronger the signal(gain) better more stable reception.
With longer cable run over 50' you are losing precious signal. At 100' you are between -5.75 to 6db of signal loss with no preamp.
This can affect the Buffalo stations reception greatly.
With a preamp it boost the max antenna signal before there is any signal loss and push the signal down the cable. At the end of the cable run you will almost have the same signal strength as if you has a 6 foot cable run.
With a booster at the end you already have lost the precious signal and will end up boosting what ever is left over for distribution. Indoor booster also have more noise.
Plus a 4228 has over 3 to 3.5 db more gain in the mid UHF(30 to 42) band where most of the Buffalo stations are.
I would replace it with a 4228.
2008-07-29, 02:46 PM
I have one DSS cable going to my basement LCD. 4LNBs, one Diseqc switch.
It's impossible with the finished basement to run an additional RG6 cable for the ATSC.
I already tried a DB4 bellow the roof line and got 9 out of 10 signal for the CDN channels and 1-3 bars for Buffalo.
Beside finding a better position for the antena I'd like to add a preamplifier. I am wondering if I can use the amplifier together with my existing DSS setup?
With other words, to use a joiner for the OTA cable and the DSS one, and in the basement to have a splitter for my satellite receiver and for the ATSC tuner. My understanding is that this is possible, if I got it right.
But, can I add a preamplifier too?
The amplifier to be in between the OTA antenna and the joiner and the power supply inside? If I can do this, where should I put the power supply? Before the splitter? Is the power supply going to affect the Diseqc or my LNBs?
Thanks a lot.
2008-07-29, 03:20 PM
markham, you are talking about diplexers. Use that term in the Search This Thread tool (to the upper right) and you'll find descriptions and wiring diagrams in this thread.
2008-07-30, 11:21 AM
I read all the posts above but I couldn't find the answer I was looking for. I posted a picture with the setup I'd like to have, 4 dual LNBs and one OTA antenna going to two TVs.
I am aware I may need a preamplifier or an amplifier for the OTA. The cable is in the range of 50' but splitting it ... I guess I need to boost the signal.
Any help would be appreciated.
Thanks a lot.
2008-07-30, 02:15 PM
In your diagram you would put the Preamplifier right up at the antenna, and then you'd need to put the Preamplifier's power supply somewhere up there with it.
If you cannot do that (i.e. lack of 120VAC receptacle in attic) then you can locate the power supply anywhere higher on the chart than where the first diplexers show up downstream.
If you insert the Power Supply below the top splitter, that splitter must allow DC Power Pass through the lead you've decided to put the power supply on. You have to be certain that the splitter does that, so if you don't see it on the label you are probably out of luck. No big deal since a high quality DC Power Pass splitter for satellite and OTA is not much $$$.
Diplexers allow DC Power Pass but they are carrying the power to the satellite LNBs so if you inject Antenna Preamp power in there you'll have big problems with everything! That's why I say make sure your OTA Antenna Preamp Power is injected above the first diplexer(s). Be extremely careful about not getting DC power-carrying lines mixed up.
Regarding your Diseqc switch, I'm pretty sure you need just one 4x2 and not two 4x1. I don't want to discuss Diseqcs here in the OTA Forum so if you're unsure please ask about that in the FTA Forum and not here.
2008-07-30, 02:34 PM
Thanks a lot stampeder and Yaamon!
In the meantime I met Yaamon and I got a CM4221 from him. He was so nice and he spent with me ~45 min explaining what are my best install options.
Yaamon had a similar installation where the antenna was hooked up straight to the preamplifier, then the coax was running inside the house\garage to the power supply, and then back outside to the splitter.
Combining signals is tricky! I get away with it easily because the CM 7777 has a separate input for UHF & VHF. But combining two UHF signals is another story.
I think you have two options:
1) Get a cheap RF switch. This RF switch has two antenna inputs and you select the desired antenna by selecting it on the switch. This will require two RG6 coax going from antenna to switch. I've seen these switches at Addison and even at The Source (but more $ there).
2) Get a set of bandpass / bandstop filters from Tin Lee. This way, you place a bandstop filter on the UHF antenna aligned on Mt. Mansfield and you place a bandpass filter on the UHF antenna aligned on the CBC building. Both these filters will have to be set for UHF Ch. 19. This will be pricey though and may not be what you are looking for as you are moving soon.
Yes, I installed my setup all on my own. It did take some time and I later improved the reception by testing small changes one at a time...
2008-08-05, 11:17 AM
The switch sounded like a great idea, except I would have to do some FUN things when it's SCANNING for channels. I would have to ensure that the switch for the antenna pointed at CBC/SRC is "on" when it's tuning, then SWITCH to the main antenna for all other channels...not that big of a deal.
I could go with the cheaper Join-Tenna from Channelmaster, it does the same as the other device you mentioned, but is much cheaper. I just got the Olympic itch in HD...must watch it in HD!
I have the amplified version of the Terrestrial Digital Lacrosse Antenna.
I want to distribute the signal to three televisions. What is the best way? Do I take the amplified signal and then feed it into a 3 way splitter?
What type of splitter?
Thanks in advance
2008-08-07, 05:24 PM
Do I take the amplified signal and then feed it into a 3 way splitter?
That is the usual and most economical way. A standard 50MHz-1000MHz cable splitter will work fine (the same type the cable companies use.) As usual, I recommend RG6 and good compression connectors. (Again, same as the cable companies use.) Two 2-way splitters can also be used, if that makes cabling easier or shorter. There will be a 3db-6db signal drop with the splitters but the amplifier should easily compensate for that.
2008-08-07, 05:57 PM
Watch your splitters though.
I believe 3-ways are often unbalanced (in terms of signal output per connection), so one output will be stronger and two will be weaker (or the other way around).
Just check the markings on it, and if one length of cable is shorter or a tuner is better on a certain run, send the weaker signal to that tuner.
i hate tv
2008-08-07, 06:45 PM
Watch your splitters though.
I believe 3-ways are often unbalanced
Thats correct. Most 3way splitters will drop 3.5db's from 1 output, and 7db's from the remaining 2 legs. I have seen 3way splitters that had even 6db losses from each leg, but can't remember the brand.
2008-08-07, 06:58 PM
Most 3 way splitters are just two 2-way splitters in one case. I've seen one in use with even losses on each leg as well but never in a store.
2008-08-07, 10:42 PM
Hugh, if you go the amplified-antenna-through-3-way-splitter route you should put the coax strand with the longest distance onto the lowest loss tap to give it a fair chance. Fire up all the ATSC tuners at once and test on the one with the longest coax length to see if you are getting locks on all the stations you want. Try scans on all of them and note any differences so that you can get the feel of what is and isn't going to work.
If things aren't going well, can you shut off the antenna's amplifier to run the unamped output into a proper distribution amplifier?
If you cannot shut off your antenna's amplifier you are probably looking at a replacement antenna feeding into a distribution amp (like in the Knowledge Base Post #6 diagram). Such distribution amps have several taps, and you would want one with the lowest noise rating you can find.
An alternative that I've used succesfully many times is a very strong preamp like a CM7777 or Winegard AP 8275 mounted right up at the antenna feeding into a multi-tap splitter instead of a distro amp.
I'd drop by and have a look at your rig but its a bit of a drive... ;)
2008-08-08, 07:23 AM
I've seen one in use with even losses on each leg as well but never in a store.
I belive the Phillips brand 3-way splitter has even losses on each leg, though I don't know how good they are. Not to name names, but I saw them at a popular department store that moved from the US to Canada about 15 years ago. ;)
2008-08-08, 09:04 AM
Hi Hugh, ;) I agree with stampeder.
I just looked up your specs of your antenna and your antenna has a raw gain of 10.8db. The amp itself has a gain of 17db should be more than enough. If I remember your cable run from the antenna was also short which helps.
The amp your antenna comes with should works well with a passive 3 way splitter.
Just hook up a splitter at the end where your current tv is and check the signal strength before and after you install the splitter.
Signal should not drop more than a few %.
Good luck, and remember if you need my help you know I'm only a call or email away. :)
2008-08-14, 03:00 PM
Anyone have any experience with this A-B switch?
What about the A-B switches available at The Source?
I'm hesitant to shell out the money for one of these just in case they are cheaply made (i.e., don't have high isolation). I guess I could always bring The Source switch back but it would be harder to return the Radio Shack one since I will have to buy it in Buffalo.
2008-08-14, 03:07 PM
The Radio Shack (U.S.) 15-1968 item was out of stock for a very long time so its nice to see it back. My only issue would be whether I could put its remote control codes into my Harmony Remote. Likely the answer to that is yes. Here is the user guide for it: http://rsk.imageg.net/graphics/uc/rsk/Support/ProductManuals/1501968A_PM_EN.pdfInsertion loss: 1.5 dB
5 - 216MHz 80dB min
216 - 550 MHz 65dB min
550 - 900 MHz 50dB minAs for the mechanical switches from The Source (Canada) you are right that you need to be able to return them for a full refund if you're not satisfied. In my own experience over the years I've found very few consumer-grade mechanical switches that consistently gave clean, interference-free performance reliability in the long term.
2008-08-14, 07:52 PM
Thanks Stampeder for the insight. I called Tin Lee and asked about their 2x1 RF switcher with the remote control. The guy didn't give me a price but he thought I would be OK if I went with the Radio Shack model w/ remote.
I think I'll pick up one when I'm in Buffalo next month. Once I have tested it I will post the results here.
Do you know if those isolation numbers are any good? I know that the proof is in the pudding, but I'm curious to know what you think of their posted specs.
2008-08-14, 08:59 PM
The higher the isolation numbers, the better, and the 15-1968 has very good numbers at that. Its not until you get into the UHF band that the isolation seems to drop down to levels equal or just a bit below what you might find on hiqh quality mechanical A-B switches (~60 to 70dB), so to me it looks just fine.
I just checked Tin Lee's numbers for their TL-EMS-1x2 remote controlled A-B switch and they show about 60dB so I think the RS 15-1968 is as good as you'll find.