OTA Antenna installation w/622 question??

[cbagman]

I apologize if this is not the correct forum but I have a question about HDTV antennas. I currently have a 622 and live in Richmond, VA (no HD locals through DN scheduled here). I read another thread about getting the OTA HD channels and took the plunge.

I purchased a few antennas that did not work well and finally settled on a Terk TV55. I looked at antennaweb's website and have the antenna mounted outside in the best place to receive the digital local signals (tried 15 different locations outside). I live about 7 miles from all of the broadcast antennas. I have a long cable run of about 100 feet so I purchased a Terk In-line amp and have it installed towards the end of the run (closer to the 622). CBS, ABC, and Fox come in very well and look amazing (80-90 signal strength). NBC comes in and out (around 70 signal strength). I'm so close to everything being perfect but NBC drops out quite a bit.

Is it possible to use more than one in line amplifier on a cable run of 100ft? I don't want to short a circuit but I feel like if I had a bit more amplification, it would solve my problem. Any other suggestions would be welcome. Thank you very much, in advance, for your suggestions and help.

OTA HD is AMAZING!!

 

[garys]

You can try the in-line amplifier, that does make the most sense. But if that doesn't work, try going the other direction as far as range of antennias. You may actually be too close to the broadcast towers and what you are seeing is the result of the signal being short circuited already.

 

[cbagman]

Thanks for the suggestion. I already have one amp installed - is it okay to have more than one on the same cable run? Thanks!

 

[garys]

If you already have one on the line, a second one really won't give you too much more, unless the line run is around 100 ft. or more.

 

[pdxsam]

I purchased a few antennas that did not work well and finally settled on a Terk TV55.

I have this antenna from Radio Shack:
http://www.radioshack.com/product/index.jsp?productId=2103084&cp=&kw=antenna&parentPage=search


I'm about 9 miles from the towers, line of sight. I had to put an outdoor antenna up because where the TV's are in house is directly opposite of clear sight for a silver sensor.

This antenna works great. What I did was not extend the back two sets of directors to make the antenna more wideband and not so much gain and it works like a champ. I used to have dropouts and lost picture until I closed the two back sets of directors.

My run is about 75 feet and I don't use an amplifier.


Sam

 

[jrfuda]

Have you tried pointing the antenna right at NBC. In my experience, a 70% signal is more than enough for reliable HD reception IF you have no multiplath issues. I can get some stations perfectly in the very low 60's, but I have one station I get at 74 that has a lot of macroblocking due to multipath. I'm currently experimenting with different wayd of dealing with this - mostly nby giving the questionabel station its own antenna and using a CM Jointenna tuned for that station - but I can't report my resuilts yet, as the Jointenna is special order and I have not received it yet.

Again, try aiming the antenna right at your bad station, at the expense of the others, and see what happens, The others may come in fine with lower signal strengths.

 

[bhelms]

cbagman - I believe the TV55 already is amplified, and you also add another Trek in-line amp. Is that what you're doing? For you situation that is probably way too much amplification! I'm not sure the TV55 is the best solution for your situation.

In general a preamp should be as close to the antenna as possible, not at the receiver end. The goal is to boost the signal as it enters the cable to make the desired signals more powerful than any interferrence you might pick up in the cable itself. Are you using RG6? For OTA, better if it is quad shield to help reduce interference. You can actually pick-up multipath in the cable, and as jrfuda indicated, multipath is more of a problem for digital, vs low signal strength.

I am curious, tho'...have you tried the system without any amp? At 7 miles, you might be receiving too much signal on some channels and that can be overloading your amp, causing problems with all channels. I'm really surprised at that range that you can't just use an omnidirectional, short range antenna without an amp to receive all channels, but the omni will have more multipath problems and that might be what's causing your drop-outs. Are you near tall buildings or something similar that can reflect signals? Added amplification won't help with multipath. You'll need to resolve that first using directional antenna(s). Try what jrfuda is doing - Perhaps an omni with a trap to block your NBC channel will work best for the other channels, then combine that with a directional antenna pointed to just the NBC channel. I'd also try without the amps...

 

[cbagman]

jrfudea / bhelms - thank you very much for the advice. This gives me a few options to try. I tried the TV55 (which is amplified) without the inline amp at first and had 60-70% strength on all station with major video dropouts. The in line amp definitely helped as I have a cable run of around 100ft. I am using RG6 and never would have known that it could be contributing to the problem. I am not familiar with quad shield cable - is there a certain name I should look for?
I am not near tall buildings - just a few multi story houses - one of which is blocking direct line of sight for NBC's tower. I like the trap idea and that may work well with an antenna pointed directly at NBC's tower. I NEVER would have thought of that guys so thank you very much. I'll try the easier solutions first and will post the results. Thanks again!!!

 

[cbagman]

I ended up taking the Terk InLine amp off of the line all together. I went to Radio Shack and got an attenuator and an FM Trap. I wanted to try both. Tried the attenuator and (obviously) the signal went down and it did not help the problem. For some reason, I put the FM trap on the line and it has fixed the problem thus far. I'm not shure how or why but the signal is locked. For anyone having similar multipath issues with their OTA Antenna, you may want to try these options. Attenator AND FM Trap cost $10 total. Easy, cheap fix. Thanks for your help guys!