The Official AVS Antenna and Related Hardware Topic! - Page 463

ctdish wrote:

"I am not sure what a CM1220 antenna looks like. Satellite dishes are deep for a UHF antenna and probably should be feed with a fairly low gain UHF antenna perhaps one with two bowties and a reflector. Also the beamwidth will be very small in both horizontal and vertical planes so aiming will be very critical in direction and in vertical elevation. You might need to tweak the tilt angle after it is mounted."

Hi ctdish,
I mixed up the antenna part number, I am using the CM-4220HD which is a 2 bowtie antenna, similar to what the old 4251 used. I think you are right about the tilt. I found it to be quite sensitive while testing on the ground. I will kick it up a few degrees when I reinstall it.
Do you know of anyone doing this?

Mike

I use a level to preset the elevation angle of a dish. The first step is to calculate the desired angle, and then figure out the gap required with a 2' level. Common angles require a .25" gap at the bottom of the level in order to aim to a mountain top. In flat land and aimed at a distant station the back frame of the dish would be perfectly plumb.

I've finally cut the cable and started shopping for an antenna...having a hard time deciding, and hoping for some good advice from this forum. My TVfool report is attached. I'm just trying to get the big 3 networks right in the city, as well as WJSU. I'm fine with an outdoor antenna...whatever it takes to get the best picture quality. I'm dragging my wife along kicking and screaming, so it needs to be easy (no rotator or gain knob to mess with). I've looked at the Winegard 1080, but not sure if it will receive Channel 9 from 30 miles out if it's pointed at the nearby UHF stations at 015 deg. Can anybody help me out?

Ah, yes...it wouldn't be any fun if the wife wasn't kicking and screaming, would it?

To make sure that you get ABC, you want a 7-51 or 7-69 antenna. The 1080 only pays lip service to VHF, although being only 5 miles away should make it easy. I would try the RCA 751 (aka EZ-HD), which is only 3 feet long and made by Winegard. It will get all of those green-level stations, with the possible exception of WUOA, which you could get with rabbit ears. You would aim the 751 to the northeast, and find a sweet spot that gets all of your stations in the 13-85 degrees direction. I would think that you could get all of them on down to WTJP, and you should not need an amplifier at all.
Going with a big rig (huge antenna, rotator, wife screaming louder) would only get you a limited number of additional channels, and isn't worth it unless you are like me and have nothing better to do.

Now that the tropo activity has subsided, I can make some more objective judgements on my new 91XG. There is a marked improvement in all of the channels with NMs below +5, with those above RF 35 showing the most improvement.
With my dish 722 dual-ota tuner, 60 is the digital cliff.

As you can see, stations on freqs up in the 40's showed big improvements, especially WMSN-47 on RF49. This station will be changed to "daytime" thanks to the XG. WISN-12, WBME-49, and WTMJ-4 have crossed over from being merely watchable to now being solidly reliable.
Some Madison stations with Chicago co-channels, which only come in with a bit of tropo help, are now much more likely to do so. The high rear and side rejection of the XG, combined with the laser-beam forward gain, now allow for the strong reception of 2 stations on RF25 (one far-away full power, and one local low-power) by turning the rotor.
And one more thing- the XG really rocks on analog, too. A couple of very weak analogs in Chicago now look better than anything I had when I was a kid.
So far, I'd have to say the 52 bucks was money well spent.

 

91XG Performance.pdf 24.5791015625k . file

I grew up in Kokomo, IN, during the precable days and rooftop antennas were as common as mailboxes.

An ANT 751 should pick up all your channels of interest. This antenna is tuned for channels higher than WUOA (7 and higher), but WUOA is so strong at your location that it should still work.

Start by aiming it at WJSU, your weakest station. If all is good, leave it in that position. If some of your other channels's signal strengths are low, move the antenna to the left in very small increments until you find a sweet spot somewhere between 60° & 16° compass direction.

The ANT 751 is small and comes with its own J-mount bracket.

I would forget about the 1080.

Thanks!

Thanks for the update.

I've been toying with replacing our old style CM4228 with an 91XG. We need a few more dB on RF channels 39-43. The most important for us is Boston WGBX, channel 43. There does not appear to be a clear winner in a CM4228 vs 91XG shootout so I've been holding out hoping Antennas Direct will do an optimized 14-51 version. The reduced bandwidth ought to move the gain peak right where I need it.

The polar plots don't look all that different between the 4228 and XG but from everything I've read it appears the 91XG is more directional. That ought to help here in terrain challenged, forested NH.

Tschmidt,
Have you tried your current antenna in different locations or different heights at the current location? Sometimes a foot or two higher or lower can make a huge difference when hills are in the way.

Higher is not always better.
http://www.hdtvexpert.com/?p=134

Not really.

Mast is gable mounted so it is not feasible to move to another location. I'm using an unguyed mast so cannot go any higher. When I put it up a couple of years ago though about experimenting with different heights but was lazy. Because of the height have to take it down to relocate antenna on the mast. In my "lazy" defense the antenna is about 30' high with skyline tipped up about 10 degrees due to 70' high trees in front of the house. Do not think lower position will help, but have no data to verify that assumption.

If I change out the UHF antenna plan to stick it on a temporary mast so I can experiment with fine tuning height.

How much you want for that old 4228? The only way to get one now is there's a guy in Sterling, Illinois who has 3 brand-new 3021's on eBay for $30 each. I suppose that two of them could be ganged horizontally, and a harness like the one on Antennahacks would really rock.

The XG is really cooking on the higher freqs, and even a few of the lower ones. A real suprise is W25DW, a low-power Home Shopping digital on RF25. This station has a pathetic noise margin of -17.3, and yet the XG is pulling it in during the day. And it has a full-power co-channel up in Milwaukee with a noise margin right at zero, so the side rejection is great. Rear rejection is also impressive, as I've been able to grab several Madisons each night that have powerful co-channels behind the antenna. I think the XG's reflector might be a lot more effective than it looks like.

Heh, I was surprised with a low noise margin Home Shopping channel a few years ago too. Turns out, that particular network likes to use a lot of repeaters, that TVFool doesnt list. You'll have to dig deeper into the FCC data base to find your real transmitter.

Actually, my Home Shopping channel is on RF25 too, so we may well be talking about the same network.

No such plans are currently in the pipeline. The 91Xg is such a low-volume item that it simply would never pay off to develop and produce a re-scaled unit. Besides, while the current frequency range isn't optimized for the 14-51 range, it's still pretty darned good out in the real world (where it counts). FYI, it's looking like the rescaled 2- and 4-bay bowties will be available sometime this fall. I field tested prototypes back in March and I know the pre-production tooling has been ordered.

Keep in mind that Yagis and bowties will always have gain vs frequency curves that look almost the same as to the slope since they are inherently a narrow-band antenna. If you want a broadband UHF antenna with a nearly flat response across the design band, the tapered loops on our ClearStreams will do that, but it becomes quite cumbersome to achieve gains much higher than 12 dBi.

No repeater on this one, it's broadcast from the Aon Center in the Loop (not the Sears, Hancock, or Chump towers), so it's about 350 feet lower than the other Chicago transmitters. Only 12.5 kW, and it's directional to the southwest, whereas I'm northwest of it.

http://www.rabbitears.info/contour.php?appid=1418918

recommend me an antenna for my mother's place to be mounted on the roof to get the channels in sioux falls, to the SSE. The more powerful the better. Thanks.

If that were my TVFool and if KTTW Fox was the lowest station on the list I was interested in, I would get this antenna:
http://www.solidsignal.com/pview.asp?mc=03&p=HD7694P
If I also wanted KWSD CW, I would get something bigger:
http://www.solidsignal.com/pview.asp?mc=03&p=HD7698P

For a long coax run or if splitting to multiple TVs, add this preamp between the antenna and the splitter:
http://www.solidsignal.com/pview.asp?mc=03&p=HDP-269

I have a rabbit ears antenna with a flat 300hm connector which I attached to a 75 ohm adapter and plugged that in to my digital TV converter box. It works pretty well and the box picks up quite a few digital channels.

Can I add a UHF loop by just attaching the loop's 300 ohm connector ends to the same screws on the 300 to 75 ohm adapter where the VHF cable is attached and using the UHF and VHF antennas together? Or is there some special way that the UHF loop antenna signal should be added to the rabbit ears VHF connection that is more complicated?

Thanks

It works, but you'd be combining the signals from both antennas, with will probably weaken some channels.
Better to use a UVSJ, or UHF-VHF signal joiner. It has an input for each and the tuner will only use the rabbit ears for VHF and the loop/bowtie for UHF. Radio Shack has them in 75 ohm and 300/75 combinations, for under 10 bucks.

I would recommend trying a bowtie alone before adding the rabbit ears and bowtie together. The same connector you are using for rabbit ears will work for the bowtie. I say this because, when I combined the 2 antennas with the 4-screw uhf/vhf adapter, my reception was considerably worse for uhf signals. Also, be aware that the bowtie alone may be able to receive vhf high signals. Aim for one channel at a time.

I live in Indianapolis and was looking for an antenna recommendation. I've attached my TVFool report. I was hoping for an attic mounted antenna but I can mount it on the peak of my 2nd story facing north as well.

Thanks in advance for your help!

Either one of these, aimed N/NE should get your stations of interest, and probably even those to the South (around 200° compass direction), off the back side of the antenna.
http://www.amazon.com/gp/offer-listi...8762454&sr=1-1
http://www.amazon.com/RCA-ANT751-Out...B5C/ref=sr_1_1

Thanks for the recommendation. Can either of these antennas go in the attic and still pick up well? Thanks.

The CM4221HD is UHF only, for VHF also (CBS and NBC) the CM4228HD would be better.

http://www.amazon.com/gp/product/B00...rev_prod_title

CBS has a UHF translator. And at his NM, the 4221 will work fine for channel 13 (nbc). The 4228 is often too big to fit through an attic opening.
@DefelRadar,
Attic reception, like indoor reception, is unpredictable.

I hadn't noticed the translator.

Can't it be broken down and re-assembled in the attic? Are the fasteners that hold it together removable?

Hello, I live in Chula Vista, CA (suburb southeast of San Diego). Roof mounted antennas are against HOA rules so I need an attic config. The diagonal for my attic access is 35 inches (probably not an issue if I assemble the antenna in the attic). I am primarily interested in KNSD-TV, KFMB-TV, KGTV-DT, KSW-TV but would like to receive as many channels as possible. Attached is my tvfool report. Thanks in advance!

You have several VHF stations. Those are often difficult to receive reliably with an attic antenna and reception is impossible to predict, due to building material variables. You also have stations in multiple directions, which may require a rotor, or a multi-antenna setup.

Per the FCC, HOAs can not restrict TV antenna installation on your own private non-common property, unless you live in a historic district.