I recently bought an RjTECH RJ-1000ATSC ATSC Digital TV Tuner and hooked it up to my coaxial cable which is part of a six story building, and has huge sets of antenii atop. The antenii give me very good analog recpetion through my VCR (being used as a TV tuner atm). According to my online research, any UHF capable antenna should be able to recieve the ATSC signal, yet I get nothing... zero.

I have tried with a smaller attached antenna to test the ATSC tuner and it works OK with them, obviously the signal is not great and not all channels are recieved all the time, but how can a small antenna do more than an entire set of antenii positioned all over the roof of a huge building.

Don't know if this will interfere, but the building also has private channel 6 (internal analog signal) sent showing what the security camera in our lobby is recording.

Any idea's why I can't catch any ATSC signal in my building, or any other torubleshooting steps anyone can suggest for me to take.

Thanks in advance

Nearly all master antenna systems in large buildings use single channel VHF amplifiers that are each dedicated to one channel, and their outputs are combined for distribution. There are typically just a few local UHF channels that are downconverted to vacant VHF channels and then filtered and amplified also.

There are very few master antenna systems that distribute UHF channels on their natural channel numbers, and the few that do usually filter off all the other frequencies so that they can be more efficiently amplified and balanced, meaning that the ATSC signals you desire are filtered off by your building's headend. What city are you in? What is your zip code?

Brooklyn, NY, 11235

So you suspect it is a filter blocking the ATSC signal?

There isn't a filter dedicated to blocking them. There just aren't any headend electronics dedicated to developing them.

Your system probably has VHF channels 2, 4, 5, 7, 9, 11 and 13, and maybe channels 25 and 31 are electronically downconverted to vacant VHF channels like 3, 6, 8, 10 or 12. There are no electronics to support the reception and amplification of your digital UHF signals.

All eleven of your local digital transmitters are presently on UHF and are in the same direction, and all but one, channel 25 are in the same tower farm, so someone could probably get you pretty good digital reception by just amplifying whatever comes off a single broadband antenna pointed in that direction and diplexing it onto your master antenna system's VHF output trunkline. They might benefit by filtering off or perhaps attenuating local independent channel 25, which would otherwise gobble up a disproportionately large share of the amplification power because it is closer than the others. I've installed this kind of add-on UHF HDTV system in a lot of large buildings.

You might want to check out this thread:

http://www.avsforum.com/avs-vb/showthread.php?t=779057&highlight=MATV

I recently bought an RjTECH RJ-1000ATSC ATSC

I did a Web search for the RjTECH RJ-1000ATSC ATSC Digital TV Tuner and found that it is not a HDTV tuner, but a digital to analog tuner that outputs 480i only. I guess that is what you wanted and needed, and that is why it is so cheap in cost. I assume your TV is not HDTV capable of 720p or 1080i? Is that correct?

Sounds like you might want to try a Silver Sensor (sold as the Philips Indoor HDTV Antenna (PHDTV1) indoor antenna), available from Circuit City for $24.99 delivered. If you want a real HDTV tuner, you need the Samsung DTB-H260F, also available from CC for $179.99.

IB

Sorry for such a late reply but was very busy at work.

@AntAltMike
Thanks so much for your detailed explaination of what is most likely in need of being done. As it turns out my co-op actually doesn't own the antenii on our roof but rent it from Sprint/Nextel and they are responsible for any changes or repairs. I put in a request through the proper channel with hope it will be done within weeks to come as this will not be a speedy process at all. Thanks to your detailed explaination I advised them of what is belived to be happening so that they simply don't sent a tec to check the signal and say its OK. Guess I will have to wait and see what happens next. I have a feeling this may actually take months.

@inky blacks
Yes the receiver is a cheap one and my Panasonic Plasma can do 1080i/p but I am happy with what I got, maybe in a few paychecks I might upgrade, but I wan tto ensure good quality signal and no problems occur (as I have been experiencing already) before spending more money on a "real" tuner. I will def keep the model you suggested in mind. Also, big thanks on the home antenna suggestion, perhaps it will do for a $28 substitute until they get mine atop my roof going properly

I will keep this post updated when my setup is complete, thanks to all who helped me and made these wonderful suggestions!!!

I wonder if your building management actually meant that they "rent out antenna space to Sprint/Nextel"?

I never heard of those companies owning MATV systems, but they buy rooftop space from many tall buildings.

@kenglish
yes you are right, they confused me about that, we do rent out space to sprint/nextel

We had after all this time wait an antenna company come by, they changed the antenna which was very old to a newer antenna which does digital better, and added some amplifier as the super called it when he told me what they did. Sure enough, I tried it again with my RJ box, and it works, although I do not get all digital signals, in fact I gew very few, I catch about 6 channels.

Is there any reference on line which can show whats available in my area or perhaps a channel guide, for example 5501 channel being old type channel 5 is confusing. I would also like to know if certain channels are availabel in my area before I complain again about lack of reception. I currently get 5, 9, and some other channels as well.

http://www.tvfool.com/index.php?option=com_frontpage&Itemid=1

http://www.titantv.com/

http://www.checkhd.com/aw/welcome.aspx