Local Reception Challenge ... the attic.

[MikeInRI]

Hi,

First off, I just found this site a few hours ago and, WOW, what a great set of tools!

My project is to improve reception on two TVs for several local channels while not affecting the good reception I have on other channels.

http://www.tvfool.com/?option=com_wr...8d177350d0a3b1

Here is the layout. It's a two story house:
TV-1 HDTV on the 1st floor with a Terk rotating set top antenna.
TV-2 HDTV is in the basement being fed from a rooftop 20" round Radio Schack antenna (non amplified) pointing to 20 deg. The cable from it goes to a wall connection in the basement then from there a short Sony "injector cable" connects from the wall to the TV. The injector is just a compact signal booster and it does help with the reception on this TV.

Current Reception (both TVs have similar reception):
The reception from 20deg is very good, although 32, 39 and 41 pixelate randomly as well as in poor weather. If possible, I'd like these improved.

From the report, I don't really care about channels below #41.

Almost all the channels from 105deg need to be improved. They have various levels of pixilation in good and bad weather. The house is on the side of a hill near the top. There is a clear site to 20deg BUT in the 105deg direction, the hill rises for a while then drops away after a few hundred yards.

Plan 1 is to put an upgraded antenna system in the attic that serves both TVs. It's a standard wooden roofed attic with asphault shingles and no metal or insulation. It can afford only about 24" of height for an antenna. From reading through the forum posts and the report, it seems there may be enough NM(db) headroom to afford an attic installation. ... hopefully.

I would greatly appreciate any advice on this and the appropriate wiring stye to the first floor and basement.

Best,
Mike

[GroundUrMast]

You have a situation that calls for two antennas. I would prefer outside mounting for both antennas. However, you have the signal strength to attempt attic mounting if the attic and roof construction is not metallic

An RCA ANT-751 aimed at 105° compass should offer good coverage of the stations to the ESE. Though in the attic, a Winegard HD7694P would not be overkill.

A two or four bay panel antenna (DB-2 or DB-4 for example) aimed at 20° would cover the NE group of stations. Go larger if mounting in the attic.

There simply are no practical consumer grade products that would reliably combine all these signals from those two sources. (It's done with tens of thousands of dollars worth of equipment in a CATV head-end.)

I think the most practical method for users of conventional TV sets is to wire each antenna separately to each TV. Then select the desired antenna with an A/B switch at each TV.

There are computer and network attached tuners... You may or may not want to go down that road given your existing investment in TV sets.

[John Candle]

I agree with GUM about the 2 antenna set up. Each antenna is connected to a 2 way splitter and the outputs of the 2 way splitters go to the the Tv's. DO NOT combine both antennas on to the same coax at the same time. Use a remote control A/B antenna switch at both Tv's to switch from one antenna to the other. Here are remote control A/B switches , ab27rs and rs 15-1968.

[MikeInRI]

Thank you gentlemen... For your knowledge and time. That's exactly the help I need.

I've checked the spec on the antennae (is that the correct plural?) and the A/B switches. Now, onto getting the hardware. Are all 2 way splitters created equal?

Actually, I admit being a tech nurd. Is there a good (practical) installer reference that might include tips i.e. connection losses, noise, proper grounding, etc?

There are computer and network attached tuners... You may or may not want to go down that road given your existing investment in TV sets.

That may be in the future, I build my own desktops and I have been thinking about building a multimedia box for one of the TVs.

Once again.. THANK YOU

[GroundUrMast]

Are all 2 way splitters created equal?

No, but no need to spend ton of money. Look for those with specified loss of less than 4 dB per port... 3.5dB is a typical number. Also look for the bandwidth rating 5 - 1000 MHz (sometimes stated, 5 MHz to 1 GHz). More bandwidth above 1000 MHz is of no use in OTA reception so why pay for it.

Is there a good (practical) installer reference that might include tips i.e. connection losses, noise, proper grounding, etc?

I'll let you judge how practical this is.

RG-6 and F connector losses can vary somewhat from one vendor to another but generally plan for as much as 7 dB loss per 100' of RG-6 at the top end of the UHF band, and not more than 0.5 dB per F connector. (For example, Re. their part # 40985-CPF, Leviton publishes 0.3 dB insertion loss @ 1GHz and >30dB return loss to 1GHz)

[MikeInRI]

That reference even answered a few question I had not though to ask. Thanks again.

[MikeInRI]

While I find myself on this site again asking for advice in a different thread, I thought I would post a little update here on this thread.

- I am cured now of all desire to put an antenna in the attic.
- GREAT success putting a new ANT 751 on the roof looking at ~105 degrees. All the channels in this direction are stronger and more stable in wet weather. The ANT is on a short (~18") post screwed into the roof and has new RG6 coax running to a splitter to the 2 TV's. The older Sony came with a little "booster" cable that i still use. Otherwise, no amp needed.
- The channels coming from ~020 are just about as strong as before even though I am pointing to 105 with the ANT.
- I have not tried a second antenna pointing to 020 yet as the above fix has solved 80% of the original (local) issues.

Thanks again for the help.
Mike