Seattle, WA - OTA - Page 311

be236,

I tried vertically stacking two old-style 4228's here and I saw no reception improvement over a single 4228. I can't say anything about the new 4228, although there is a website that offers ways to improve its performance and I haven't tried an HD-8800.

Two summers ago I did an old fashioned antenna shootout and tested old versions of the CM-4228 and CM-4221 against a Kosmic SuperQuad. I did it the 'poor man's' way, using a stepped attenuator. I'll look around to see if I can find the results. The 4221 won: my conclusion is that I live in an RF soup and the smaller the antenna is, the less multipath it collects. I didn't have a DB-2 at the time but way up high it works as well or better than all of the others for UHF (at my location). Its worthless for VHF.

Jim

The only thing different in the two versions you've tried is the balun, the rest is identical.

AD just came out with their newly rescaled )14-51) bowties called the DB2e and DB4e that are somewhere around 20% larger than the old versions. They also have comprehensive tech data sheets posted for each of the new models (look under "Documents").

Correct.


ProjectSHO,

That was news to me and thank you. You are correct about its increased size and their ad is misleading -- from their website: "... We have created an antenna the size of our original DB2 ..."

I measured one of mine and the new version is roughly 4" wider, 3" taller and 2" deeper, that's about one inch narrower than a KSQ or an old-style 4228. Nevertheless, it easily fits within OTARDS limits. I'd like to try one.

Jim

OTARD doesn't have any size limits for an OTA antenna. The size limits apply only to satellite dishes. It's a hell of a lot smaller than an original 4228.

No comment about the ad copy....

You are the first to agree with my original take on the OTARD rules. Six 'authorities' I have talked to in person and on other Forums insist it also applies to OTA antennas. Well, now that makes two of us.

Yeah, at just less than half the height and about one inch narrower than an original 4228 the new DB-2e is small, but an original DB-2 is "a hell of a lot smaller", far lighter in weight and it has about 1/3 of the wind loading, not about half. I'd like to try one and thanks for the heads-up on their new products.

Jim

I don't know who could possibly misinterpret rather explicit language so as to apply the 1-meter restriction to an OTA antenna and still call themselves an authority. The FCC's and the wording in 47 C.F.R. Section 1.4000 is rather explicit in that the one meter rule applies only to DBS antennas (except in Alaska) or for receiving multi-point video or for wireless services.

I've got an original 4228 I bought back around 2002 or 2003 leaning against the garage out back. It's about the same size as a DB8 which is four (4) DB2s in a 2 x 2 stack. I think I still have a DB4 (half a DB8) in the garage. If you need it, I can probably snap a side-by-side photo of them.... Keep in mind that the 4228 is an 8-bay.

ProjectSHO89, Please scroll back.

Earlier today, I wrote I have tested a single and a vertically stacked pair of original CM-4228s so I have no use for your photo, but thank you for your offer.

If you would like to see my antenna shootout results using (original design/s) CM-4228 VS CM-4221 VS a KSQ I can post it for everyone to see and to scrutinize.

Jim

Anyone here watch CBC HD from Vancouver via OTA?

Jim
ProjectSHO89 is correct. OTARD size rules are for the satellite dish only. When they started HD broadcasting I encountered this problem many times. I also posted on several other forums with people from all over the US running into the same thing. In every case the OTARD stood up. I've only had a few customers that ran into trouble with HOA's, initially, and once I showed them the website, I never heard back, and the antennas are still up and working.

As for the 4228's, they are not worthless for VHF high band. They're not great, either, but close in, they actually work fair. It all depends on the location and obstacles in the way. Looking at a VHF channel signal on the scope, the last 20% or so falls of rapidly instead of being nice and flat. It can still work if the level is decent and you're not fighting trees or buildings. I've used the 4228 in Ballard, Greenlake, Kirkland, West Seattle and similar areas. It's a good compromise where you want to mount the antenna on the side of a house or where ch13 is not too far off axis. A UHF/VHF yagi style is far better, but requires more room to mount. It's also more narrow in reception, which can be a good thing or bad. Depends again on what you need for the location.

Doing a shootout of any antenna without a meter/scope is tough. The attenuator test does give an indication of where your receivers minimums are for reception, but if you don't know what the real db levels are to start with, your really just testing your tuner. That's okay, it's just not a very thorough test. You will find which antenna works better for your site and tuner. To say that somebody would get the same results somewhere else is just not real.
There are so many other factors that come into play. It's also why there are so many designs for antennas. They all have their good and bad characteristics.
You also need to see what the signal looks like displayed on a scope. It's why going for gain specifications are not the holy grail. You need it, but trying to compare numbers on paper are just not real. You don't know how they tested them. And if you did, was brand A tested the same exact way as brand B.
And no one tests for how they react to trees or buildings or hills or steel roofs or miscellaneous wierdness in the real world.

Stacking.
Works great if you know what is going on when seen on the scope. It's very touchy. Vertical stacking gives very different results from horizontal. And quad arrays are really fun. Spacing between them is critical for what frequency you're trying to center it on. Distance between the couplers is very important, as well as the type of balun. And obviously, the type of antennas you're stacking makes a huge difference. Did I mention the little holes you can get (losing an entire channel when all else is fine) by just turning one slightly more, or moving it up or down too much?!

So, trying to figure out what works best for a particular challenge without being able to really see what's going on is very tough. Trial and error can be done, and can work. A good understanding of all the factors involved will help more.

As for your results with two 4228's not working well, my money is on your location being so hot, and the antennas having far more gain of everything (noise, mutipath, ground waves, harmonics, the neighbors barking dog), the signal was not only garbled, but the waveshape on the scope was all over the place. Using the little antenna got you far less of all that, and your tuner could deal with it.

I do all my shootouts the hard way. Drag around the latest one, try it against my known good ones, in every location, over many months and view it on my meter/scope. After a while, you get a good idea of what it can and can't do.
If I simply tested it out at one location, like home, I might get some idea, but not a true test.

Take all the "shootouts" you read about with a grain of salt. If done with good test equipment, and the setup is explained in detail (how far the transmitters were, what power they put out in what pattern, what frequencies, their height above sea level and the testing site elevation, terrain, temperature, time of day, etc) that's good.
Hearing what one person used at one location, without knowing all the rest of their facts, only says it worked for him. The same antenna might work for many people. Okay, that's worth looking into. If all the facts match up with your needs, great. Base your purchase decision from that perspective.

Yeah, yeah, waay too much coffee again.
We need to get together and tell tall tales!
Dan

I have. Occasionally can get CBUT (CBC RF 43). But more often, I get CHAN (RF 22) and OMNI (RF 20), though CBUT shows a better NM value than OMNI. Go figure.

Jim,

I read up on that 'EV's Kosmic SuperQuad,' and its whisker length is similar to M4 that I built (10.5" whisker x 10" bowtie separation). Longer whiskers gives better gain on low UHF end.. so it's probably even or better than my poorly made M4.

When you get a chance, can you verify if they are still running at 1080i HD resolution?

Thanks.

I have TSReader data from September 3 showing it as 720p. http://www.rabbitears.info/screencap...179301-0_0.htm

- Trip

Fox doesn't own channel 13 and 22, Tribune Broadcasting does. The channel 13.1/13.2 (KCPQ-TV) transmitter is on Gold Mountain, west of Bremerton. If your antenna in Lynnwood is pointed toward Seattle, this is why KCPQ looks like Legos. You will need to find a point halfway between Seattle and Bremerton that works or add a Channel 13 cut or VHF hi antenna (13.1/13.2 broadcast on physical channel 13).

Channel 22.1/22.2/22.2 is broadcast on physical channel 25 from Capitol Hill in Seattle. 22.1 is KJZO in HD, 22.2 is KCPQ (13.1) in widescreen SD and 22.3 is Antenna TV in SD.

Val

That's what I thought, although it was reported (in various places) just after 9/1 that the CBC digital stations previously on the air were still 1080i.

Thanks Trip.

Well, since CBUT is on 720p now, it still looks crystal clear to me in HD (whenever I pick it up via Tropo conditions). heh..

I can't tell the difference between 1080i and 720p.

Like many technical issues, it may depend on how it's handled.

For example, with most ABC stations, they do 720p with at least 1 subchannel which reduces HD bandwidth. FOX does 720p with a unique HD distribution system called the Splicer that can vary the amount of HD bandwidth.

CBC on the other hand uses a consistent amount of HD bandwidth that is usually higher than other OTA networks for 720p. The result, IMO, is a very good looking HD image. I'm just wondering if regular viewers can see a difference between this and their previous HD format of 1080i with slightly higher bandwidth.

When I watch the newscast on CBC (CBUT) and compare it with ABC (KOMO) in Seattle , both at 720p, it seems the CBC broadcast is sharper/clearer than KOMO... heh.

Unless something has changed recently, the KOMO live news shows are shot and switched at 480i, even though the broadcast rate is 720p. KOMO unfortunately built their new, all digital studio just before HD equipment became available, so they said then.

So, a new OTA user should find perfect/accurate information when they access the web.


What does Google put in your face? Denny's TV Antenna Sales dot com

... "What this means is the EZ-HD TV antenna is not effected by rules and regulations prohibiting the use of outdoor TV antennas. This Federal ruling is part of the Federal Communication act of 1996 and can be viewed on the FCC website.

As you can see by the picture we didn't waste 1 inch of space. We wanted the best possible reception even for those people living in antenna restricted areas." ...



[b]For the record I have saved about three (short) e-mail conversations with Denny and he backed down after he learned I HAVE A COPY OF HIS INVOICE to a friend of mine who lives in Renton: his business sold my friend an ABSURDLY GIGANTIC antenna for his location.

If necessary, I can attach the images of BOTH the invoice and the gigantic antenna that should astonish all here.

Jim

Yeah, I know Denny's site is one of those that misinterprets OTARD. I think I've made that observation on one of these sites previously. Given his marketing and testing methods, I doubt he's going to be affected by facts....

Well a new mast and stuff is not in the cards. I was all set to go out and get the 4228 as it was okay with my budget and it sounded like an easy swap-out. Again, Channel master techs said the 4220 mast would work with the 4228. The guy even double-checked with his supervisor, of course they also told me the 4220 was big enough. He said I would have to have the antenna hang over the edge of the roof, though. Are you sure the mast wont work? Check out. The 4220 mast seems very stable and since it has a low center of gravity, I would think the 4228 would be fine. I could add a guy-wire or two, but is that even necessary? Are there any alternatives? the 4221 maybe or some other antenna where I could use the same mast?

For the record, after more watching, fox (13-1) only comes in at night, but I rarely watch anything on that channel anyway. King and Komo are hit and miss, mostly miss; especially on windy or rainy days - and those are the channels I do want.

Maybe I will try messing with the direction, and/or moving the mast a little higher up on my roof before buying a new antenna.


Thanks for the ongoing help and advice.

Given that, the 11 am news on 4.2 should look almost the same as that on 4.1 but it is much less sharp (and much less sharp than most other 420p subchannels, even those with lower bitrates).

rbico
You're welcome, always enjoy helping good people!

The guys you're talking to at Channelmaster must not be listening to what your trying to get across to them. Not uncommon. Not sure what he means by hanging it over the edge of the roof.....

The CM4220MHD I've seen has a very short mast

http://www.solidsignal.com/pview.asp...ce=google_base

The picture you enclosed is of a 4228 mounted on a DS-3000 satellite mount, 39" high.

http://www.solidsignal.com/pview.asp...00)&c=Mounting Supplies&sku=

It has a similar foot, bit bigger, but much longer vertical portion. I have used these occasionally, for special installs. It could work, but you need to brace up the mast from the back side with some long brackets. If you leave it by itself, like in the picture, it will not stay in that position over time. The antenna will work the mast against the bolts at the bottom from windy days. It's only being held in place by squeezing the pipe with those bolts. Eventually it will get loose, no matter how hard you try to tighten it (been there, tried that, learned my lesson). You cannot use guy wires, as they need to be from three equally spaced points, and one of the wires will get in the way of antenna reception.
To make some brackets to brace the mast, I use 1" X 36" X 1/8" thick aluminum L-angle

http://doc-00-8g-3dwarehouse.googleu...000&ctyp=other

Home Depot has it. Cut it to length as needed to form a V-shape, with the point of the V mounted on the mast from the back side. Anchor the other two L-bracket ends to the facia boards or roof as needed. It will be rock solid after that.
It's a bit more work than using an eave mount, and requires at least one more screw into your roof, something I try to avoid.

There isn't any other small antenna that's going to work for your location on that small mast and mount. It seems stable because that tiny antenna has no wind load, and weighs nothing compared to the 4228.
If you ever got on a roof in the wind, even light breezes, and tried to keep a larger style antenna steady with one hand, it's a surprise. Long yagi styles, too.
The 4221 antenna is the same height as a 4228, actually two 4221's side by side. The 4221 would work better than what you have, but won't help with channels 9-11-13. The 4228 will, and is better than the 4221 for the other channels.

Of course, you could experiment with other small antennas and preamplifiers. One might work. Trying to figure out which one would do it is tough. Kind of like driving down the road in broad daylight, wearing very dark sunglasses, in a car with very dark tinted windows, and trying to figure out which ultra bright monster headlights you need to buy for the car to be able to see. It could work, but you're attacking the problem bass-ackwards.

Trying a new location is always a good idea. Be patient, and give the tuner time to scan in and lock on. You can't whip it around and have somebody watch like the old analogs days. Takes 10 to 20 seconds sometimes for a tuner to get just one channel locked into memory. Just moving it 8-10 inches in any direction to make a big change.
And stay safe on the roof.

Let us know what happens.

Dan

We have to consider that the bandwidth allocated to ch 4.2 is far less than for 4.1, so the smaller bandwidth will compromise picture quality.

It is entirely possible that KOMO has upgraded their in-studio facilities to support HD now. I originally heard about the unfortunate timing leading to SD digital instead of HD from a retired KOMO engineer who worked on their analog to digital in-studio transition.

Thanks again, Dan. I will just take your advice and keep poking around with the 4220 before I move up to the 4228. I have a friend that is a welder, so maybe he can make me a basic bracket based on your idea. Good analogy with the headlights, by the way.

rbico
Good plan. Next 5 or 6 days are going to be good weather for it.
Rare thing this time of year, take advantage !
Take care
Dan

For those folks using the CM 4221 and having trouble receiving VHF channels 9, 11, and 13, here is a re-post of my earlier description of mods that can improve the reception of those channels.

 

Mods to the Channel Master 4221HD Antenna.pdf 227.759765625k . file

KOMO quietly upgraded to HD news last month. 720p on 4.1 and down-converted for the 4.2 newscasts.

Yeah, I may have noticed their newscast is slightly "sharper" recently in the last few days or so...

Thanks for your reply. I will have to look carefully at KOMO 4 News. I suspect the "quietly" was because a lot of viewers did not notice the difference.