Interesting....

I hooked up my antenna, then added my (disconnected) cable TV service in with a (backwards) splitter as well since I still get a few CDN channels on there that I don't pick up OTA. I did it this way to avoid having to switch inputs on the TV, or use an AB switch. Will this possibly cause damage to the TV/tuner in any way? I never thought about the backfeed to the cable system.

My picture on both OTA and cable seems to be fine, and my cable internet is fine, as is the cable on another TV. I suppose I could still be backfeeding OTA through the cable network though?

I was pretty surprised this even worked, as I know even using a splitter backwards for cableTV only causes problems.

Would a diplexer solve the issue/problem of backfeeding - or are they not operable in the desired range (or just cause the same problem)?

Kevin.... you're now broadcasting UHF cable signals off of your Antenna! You may think there are only a few TV channels on the line however the digital cable TV service and cable modem service are all there and in the band above 500MHz. By using a splitter you’re also sending this to the antenna and being that it's a UHF antenna it's going to be good at broadcasting these signals. You can eventually expect a visit from the Cable Company or Industry Canada Inspectors at your home looking for the signal leak. You might even be fined.

So would a diplexer solve the issue? or is an A/B switch my only option?

Could I run two diplexers (in basement and at TV), then connect to seperate inputs on the TV - to avoid running a second cable to the TV? This would be my preferred alternative to my current setup (switching inputs on the TV rather than flipping a switch in the basement). Or will a diplexer still allow the cable signals to transmit over my antenna?

Since cable is slipping these signals through for free to me (my TV service is disconnected), they shouldn't mind me broadcasting them to the neighbors :D j/k

Diplexers are only for mixing OTA and Satellite. This has been discussed in the OTA Forum previously. Please disconnect your leaking connection immediately. There is zero tolerance here for infringing Industry Canada regs, and it is a safety issue too because CATV signals can interfere with Airport ILS systems.

I don't have a problem running a new cable and using the second input on the TV and will do so. Just so you know, I wasn't aware of this issue until I came across this post, so its not like I was out to cause problems in the airwaves.

As I understand it, there is no way to use the single (in wall) cable to transmit the cable and antenna signals simultaneously. Is there such a thing as a splitter that only allows signal flow in one direction, thus eliminate the possibility of backfeeding to the antenna?

Anybody has experience with those:

http://www.auctiva.com/hostedimages/showimage.aspx?gid=19684&image=1478177&images=1478177,1478177


They claim to provide lightning protection for satellite receivers, tuners, etc.
I'm planning to by one - do they really work or are completely worthless?

Anybody has experience with those... They claim to provide lightning protection for satellite receivers, tuners, etc.Check through HDTV101's previous posts about his use of gas discharge surge protectors, including photos. I always prefer personal knowledge and experience to web site marketing claims.

Location: Corner of Front and Spadina
Antenna: Channelmaster 4221 (bought from Yaamon)
ATSC Tuner: DVICO FusionHDTV5 USB

With the 4221, connected, I was experiencing choppy results on all channels even thought the signal strength was very good. I installed a highpass filter that I got from Tin Lee Electronics to block all signals below channel 14. It worked like a charm and all the channels that I can receive are now rock solid.

I am unable to tune into NBC and WB.

DarrenT good tip about the filter.

Now we are all able to recognize the problem when you have strong signal strength and fluctuating picture especially when you are close to the CN Tower.

This is good information to know as I never came across this problem before, but now if I do I know what has to be done. :)

Tom.F.1. deserves credit for the idea about the filter as I originally got it from him. He previously suggested splitting off the UHF signals due to the potential of the FM tranmissions from the CN Tower overloading the receiver.

I was originally looking for an FM bandstop filter but after talking with the guys from Tin Lee, they suggested a high pass filter because VHF analogue channels 5 and 9 will come in strong from the CN Tower, as well.

DarrenT what filter did you get, the HP7-450 / 470 ?

Is it filtering all frequency below <450mhz, as UHF chan 14 starts around 470mhz.

Yaamon,

Yes, I got the HP7-450/470. It filters out everything below 450 and passes everything above 470. Channel 14 (i.e. Fox) comes in loud and clear for me.

Darren,
Thank you for the credit, I knew i had posted about the filter before but didn't know when or to whom. The input stage on a tuner will overload with the highest signal the antenna receives. It doesn't care what channel, the input stage is well before the tuner and so it has to be wideband.

I didn't know Tin Lee was still in business. I used to buy professional products from him for clients. (put the CATV system in the skydome).

I've been looking for a TV/FM/UHF bandpass filter all in coax. All i can find is ones with 300 ohm leads.

If you have contact info for Tin Lee, can you send it to me by PM, please.

Thanx,

Tom

This might be a reallu stupid question but... here it goes...

Is there any difference between a signal splitter (take one cable and output to two cables) and a signal joiner (take two cables and output into one cable).

My simple thinking is that internally they are probably the same thing.

Yes there is a difference. To join a OTA and a satelitte signal you'll need two diplexers. One to join the signal into one coax and another to seperate them again. Look up diplexer to see if this is what you need for the job you want to do.
If this is what you need Yaamon sold me a couple. Send him a pm he will probably help you. He is a very honest person who you can trust.

What I was looking at doing was hooking up two OTA antennas then putting into preamp and then sent to TV.

What I was looking at doing was hooking up two OTA antennas then putting into preamp and then sent to TV.

Yes you can use a good quality splitter and use it in reverse, that will work.

Make sure that the cable length is exactly the same coming in from both antenna's.

The splitter/combiner must be able to pass dc current through.

I found that when I had my combo antenna setup the preamp would not work due to the splitter not being able to pass dc current.

Good luck.

Anybody has experience with those:

http://www.auctiva.com/hostedimages/showimage.aspx?gid=19684&image=1478177&images=1478177,1478177


They claim to provide lightning protection for satellite receivers, tuners, etc.
I'm planning to by one - do they really work or are completely worthless?

look here: http://www.digitalhomecanada.com/forum/showthread.php?t=24755&page=2&highlight=grounding

They are a gas filled device. They clamp high voltage on the center conductor and short it to the ground. This prevents the high voltage from reaching your equipment and causing damage. Just be sure to install it at a ground block and make sure the ground blocks wired to a good ground.

http://vanuatusportfishing.com/UHF/gas-dischage.jpg

The more I learn about this I realize that you have to look at the whole thing as a "system" with many components".

If you have a huge antenna then you can have any components you want. But if you have better other components then the size of your antenna can shrink. The question now is how far can the antenna shrink?

Ideally I think a 4221 should be "good enough" to get Buffalo but to accomplish this you need a good clean preamp and minimal loss in connectors and cable.

I think a 4221 should be "good enough" to get Buffalo but to accomplish this you need a good clean preamp and minimal loss in connectors and cable.You and Yaamon would be in complete agreement, and many posters have said that such a system works just fine for Buffalo.