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Old 9-Mar-2012, 1:19 PM   #1
renstyle
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Join Date: Mar 2012
Location: Boone, Iowa
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Picking antenna - 23 miles out - Des Moines, IA - attic probable

Long time lurker, first time poster. Thanks in advance to all for what you do.

I've looked at *ALOT* of analyses from other locales to get to this point. At first I thought I was looking at FMfool graphs, signals around the trace everywhere for some folks!

The signals for my area are about as simple as you can get, about 140-142 magAz will get me all the locals from a pair of towers 1 mile apart.

I'm using a hand-me-down UHF only antenna right now (24ish" long, no angled reflectors) on a 15' pole on the south side of the house, works great for the UHF we have (RF 16, 19, 23), not the best signal, but far better that I expected with this setup. Most days this UHF funnels enough signal to allow us to watch RF 11 and RF 13. Spotty, but enuf for cartoons for the kids.

RF 8 and RF 5 might come in every 4th thursday.

Ideally I need a full VHF/UHF antenna (or something similar to denny's stacker).

I've got a 2-story 'foursquare' type house with a hip-roof style attic, which gives me 12'x12' free space just below the peak (about 9' high).

I do realize that the roof is better, but our house, being a big square block thing, has no easy access to the roof at all, would need a 2-story+ ladder (which I can rent periodically for gutters, but cannot afford to buy).

For my personal situation, I need access to the antenna in the attic. For better or worse, I have an older home, with no foil backed anything in the roof, no metal mesh either. Just a single layer of shingles that were put on in 2003 (was a full-tear off, no old left behind).

I've got pretty decent LOS to the towers, with good enough binoculars you can see their tops on clear days (MUCH easier to see their lights at night).

My current favorite choice: Antennacraft C290 from solid.signal

Seems like a decent mid-range rig, and the price is certainly nice. Wish they had the ability to extend the discounted shipping to the bigger rigs, but I do understand why they cannot!

The HD7084, the HD1200 and the CCS1843 all caught my eye, but after you include the shipping charges the price is more than double that for the C290.

I had also considered a new VHF only ant to gang with the UHF I have now, but moving the ant inside may not overcome the roof... Wish I had the model # for this UHF, it's a Winegard, about 10 years old.

Was also looking at an AP8275 preamp to account for losses in the 50' mainline, which then branches off to at least 4 sources (two are DTV boxes, other two are HDHomeRun for MythTV). I chose this one because it had higher gain ratings. Dunno if my situation/siting makes this much pre-amp necessary?

I'm not looking at the pre-amp to improve the signal itself, just to cover line losses as it runs thru the house.

The toughest part of this decision is how much antenna does my site "need" without being "huge overkill". You'd think only 23miles and LOS, this should be easy....(maybe it is and I'm just really dense).

I like the C290 for it's simplicity, just one lead and you're done. But if my UHF rig is sufficient (in the attic), I'd consider a VHF ant to mate with it. Will try to snap a pic of it tonite and sent it along. I've not found a VHF only ant with specs that match well with a C290, not at the sub-$50.00 price point anyway.

Terrain: as I mentioned in a previous post "flat as a pancake, with blueberries here and there to make things interesting". All of the locals are on 560m HAAT or higher.

Do I sound like a floundering fish? Sorry for that....

Thanks so much for your time!
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Last edited by renstyle; 9-Mar-2012 at 5:39 PM. Reason: myriad of spelling errors....
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Old 9-Mar-2012, 10:25 PM   #2
Electron
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Tv antennas and Tv reception

A Long Time Lurker knows that taking a picture of the tvfool radar report does Not cut it. A Long Time Lurker knows what to do to make a tvfool radar report.

Last edited by Electron; 10-Mar-2012 at 3:51 PM.
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Old 10-Mar-2012, 1:26 PM   #3
Dave Loudin
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Location: King George, VA
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Renstyle, you need to read the signal analysis FAQ that's linked to from your TVFool report. The key design variable is the Noise Margin, which measures how much signal is in the air versus the minimum to achieve lock in your receiver. Look at your report, then look at the antenna you're thinking about and tell me if that's the right one to choose.

Your local stations have noise margins above 50! Those that don't are repeaters that don't count. With a typical design goal of +15, you've got 35 dB to give, so you really don't need antenna gain, you just need no antenna loss. You can easily get by with a Winegard HD7000R, which is much smaller and another $10 cheaper.

You probably don't need a preamp, either. Remember, you have a ton of signal to work with. You're probably losing 7 dB in the cable and somewhere between 7 and 10 dB in the splits. I count 17 dB of loss so far. Toss in 20 dB loss for being in the attic, and you're still good. If you want a little more margin, either mount the antenna outside or get a distribution amplifier for your 4-way split.
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Old 10-Mar-2012, 7:11 PM   #4
GroundUrMast
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The Channel Master CM-3016 comes to mind also. Antennacraft and Channel Master are known to be fairly easy to refold if you try the attic but need to move the installation outside. As @DL is saying... you have plenty of signal to work with... keep it simple.

I would avoid trying a 7-51 or 7-69 antenna. If you want to see WOI reliably (I would), use an antenna designed for the job.

Bottom line: The HD7000R, C290, CM-3016 and similar antennas are all worthy contenders.
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