I ask this, because the CM 3414 gave me few more channels that locked on, in comparison to no amp or pre-amp.

Thanks to the generosity of a DHC member, I tried two traps one for VHF 11.0 (+72.4 NMdB/-6.4 PwrdBm) and one for the FM band to hopefully get a better lock onto the elusive 49.1 WNYO (75 miles away, -3.9 NMdB/-94.7 PwrdBm) well... it worked!

I placed the 11.0 trap after the joiner (of two antennas), and then the FM trap after, and then fed into a CM3414. This finally produced a picture for 49.1 on my LG TV. (Samsung and Toshiba TVs were a little more finicky) There was some occasional pixelation, but being February, I think this is pretty good.

I removed all the UVSJ splitters I tried before that gave me a little success, but these two traps made a BIG difference. Funny how using the UVSJ splitter, which supposedly should knock down VHF signals, including 11.0, was no comparison to the 11.0 trap.

In addition, when I disconnect one antenna from the joiner (one aimed for TO), and just run the BUF one, 49.1 is pretty solid. :cool:

Thanks again to the trap builder and thank you all DHC members. ;)

even before I read your post I just finished firing off an email to a company about a trap filter for my power house channel 10 CFPL.

Funny how minds think alike.
I like the progress and strives you have made in your setup.
Indeed I am awaiting for a return email from the company.

Mark

I'm completely new so pardon me if this is not good suggestion but is not possible to Filter out all of the RF frequencies coming off the CN tower with a different notch filter for each RF?

ie a notch filter for rf9, rf20, rf5, rf41 etc etc.

I'm completely new so pardon me if this is not good suggestion but is not possible to Filter out all of the RF frequencies coming off the CN tower with a different notch filter for each RF?

ie a notch filter for rf9, rf20, rf5, rf41 etc etc.

Yes, it is possible, but:

The cost of buying all those notch filters would be prohibitively expensive, and
Adjacent channels to each of the notches would not be receivable (ex. ch40 and ch42 to the ch41 notch).

I agree that buying would be prohibitively expensive, but for those so inclined, building is a cost effective possibility.

The only practical issue that I can see with putting many filters in series is that each filter will have an insertion loss for the non-trapped frequencies. Add up all those losses for multiple filters and you could have significant attenuation of the desired frequencies.

The design of a single channel trap may affect adjacent channels. Something like the 1/4 wave stub or a simple series resonant circuit would affect adjacent channels. Better designs will provide much better cut-off and cut-off frequencies that will not encroach on adjacent channels.

An example of a rather nice base design is found at;
http://www.ecelab.com/band-stop.htm

It is possible to build on this basic design to obtain some very steep cut-in and cut-off frequencies, but it may not be possible for the average Joe to build.

Trouble with this design is that the inductances can become sub-nanohenry at UHF and capacitance at something less than 1 pF, so one might be better off buying from those who know what they're doing.

goforit,

Did you try the traps indiviaually before you tried them together. Just curious if one trap help more than the other.

I tried the 11.0 trap first, and when I added the FM there was a slight improvement. I think the 11.0 was the key. I'll muck around some more, maybe put some attenuation (3db, 6db) on the TO antenna; got to wait till everyone is in bed and not watching TV. Cheers!

Funny how using the UVSJ splitter, which supposedly should knock down VHF signals, including 11.0, was no comparison to the 11.0 trap.

yah I wasnt impressed with what 2 or 3 different UVSjs did for me here on the strong analogs, and also degraded the UHF slightly, personally I think their attenuation specifications are VERY exaggerated

yah I wasnt impressed with what 2 or 3 different UVSjs did for me here on the strong analogs, and also degraded the UHF slightly, personally I think their attenuation specifications are VERY exaggerated
I said a few months ago, the UVSJ's weren't very good compared to specs and got shot down. I didn't need any abuse, so i just let people find out for themselves. :)

the UVSJ's weren't very good compared to specs and got shot down


I hope I wasnt one of them Tom...;)

I found two designs after looking through this thread. RamKat's stub design and this link - http://www.dewtronics.com/tutorials/descramblers/notchfilter/df222.html to a DIY kit filter. Which one did you try that worked for you, goforit?

Marbles_00
I'm the one that built the filters for goforit. The design was my own (pulled out the old college text books) and it was built from junk box parts and hand wound coils. It's nothing spectacular or proprietary and seems to work. I provided a link in a previous post to the basic circuit. The one that I use is a little more elaborate and "theoretically" provides steeper cut-in and cut-out frequencies. I just don't have the test equipment to prove anything. It was built on a protoboard and installed in recycled splitter cases.

I looked at the Rainbow TV Notch Filter Kit and simulated it. The simulation actually doesn't look too bad with about 30 db attenuation across a channel when tuned. For $15.00 it might be worth a try. I think I might try to prototype that circuit tonight for kicks.

I am trying to plan my OTA antenna installation and would make things easier if I could use all my existing Bell Expressview cable runs from outside into all my rooms. Can this be done? They have installed some sort of large splitter in the basement where everything goes to the different rooms? Can this also be used or do I need a new one?


Thanks for you help!

Steve

Thanks libiec. I missed that link above. Didn't realize something that was very recently posted.

Now have a few things to play with...oh I love new projects. DIY all the way.

Well, I'm no expert myself, but generally Satellite installations are done with RG6 coax cable, which is what you would want to use for OTA as well.

Question is, are the coax runs in your house also RG6?
If so then you should be fine, but of course the quality of the signal will also depend on the splitter being used and how many times you split the signal, as well as how long the cables are.

In my house, I believe the contractor used inferior RG59 coax for all the runs, and yet the signal strength and quality is still fine, as the length of the runs are minimal (I did use RG6 from the antenna to my splitter before all the runs though).

I'd of course suggest you read over the FAQ several times, loads of good info and links for things you'll need.

Cheers and good luck!

This application is what satellite "diplexers" were invented for. They're used in pairs: one to combine the OTA with SAT onto a single run of RG6, and another to split them apart again where needed.

-ml

What is this large splitter? Does both lines from the LNB goto this splitter? How many lines come out? You may have a multi-switch to allow for multiple receivers to be connected at once and not a splitter.

Depending on where your dish is outside, the worst is running an additional line into the house to that "splitter" location. If it is indeed a switch, it could be a 3x4 switch, meaning 2 inputs are for your LNB sat connections. A third input is for OTA/cable connection, so the switch combines all the signals together. Then at each TV, use a diplexer, as mlord indicates above, to separate the signals to their respected Sat and OTA, then connect those to your TV.

The big issue is that some of these switches have a big insertion loss. I have one which the specifications say is around 14dB. The diplexers I have, I've also noticed have about a 1dB loss. All this adds up to an un-reliable signal on some channels.

My other concern, and it is something to keep aware of, is that the sat lines have a DC voltage on them. If you should have to pre-amp the antenna line, you could run into un-foreseen issues at the dish/antenna location. In some ways, it's better to keep them separate until in the house, then combine them. This way, if your external cable length is long, you can pre-amp the OTA line without issue with the sat LNB power.

I have a wierd situation that I am having a hard time making sense of. I've got an antenna being fed into a line going to my TV using a diplexer, and a diplexer at the other end splitting to a satelite receiver, and my HDTV. The antenna works perfectly in this diplexer setup, until I add the satellite signal at the source end. As soon as I add the satellite signal to that diplexer, it's like I have no antenna at all.

Can anyone give me any clue as to how/why this happens? Is there anyone out there living in the Ajax, ON area that could give me some sort of consultation on this?

(By the way...I actually have a proper 5x8 satellite switch that I want to use, but when things weren't working with that, I thought I'd try to simplify things a bit, and just tried the two diplexers...which is where I am now)

FYI: Some DirecTV systems are incompatible with OTA diplexing,
since some of the SAT coax frequencies overlap OTA frequencies.
Suggest you move the query to the appropriate SAT thread....

Hey Holl_ands...if that response was for me, my satellite switch is for StarChoice/Shaw Direct. If that's where I should ask, then I can do-so, but really, my main problem is lack of knowledge about diplexers which is why my search brought me here. (I'm still hoping someone can help me out a bit)