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View Full Version : best rooftop directional for adjacent DMA? DTV ONLY PLEASE!



TomCat4680
04-27-2009, 05:55 PM
Hi I'm in the middle of DMA 66 (Flint / Tri Cities, MI) and I'm looking for a directional rooftop antenna that'll pick up more DMA 11 stations (Detroit). I just bought a DirecTV AM21 Off Air Tuner then picked up a Radio Shack Remote Control A/B switcher (one antenna for Flint digital subchannels not on satellite and the other for Detroit) and hooked them all up and my reception of Detroit channels seems to be worse than when I hooked just my indoor directional straight to the TV. I'm looking into getting a directional rooftop outdoor antenna for Detroit and possibly a pre-amp to solve multipath interference and digital cliff effect issues. I need a small one too.
I'm in a 2nd story apartment and the only window available where I wouldn't be tripping over cords faces east. Also, I'm on a busy road and the signal always drops out for Detroit channels on my directional indoor whenever traffic gets too heavy. Oh I also have the Detroit antenna hooked to a distribution amp.

Help?

NN2E
04-29-2009, 03:49 AM
Hi TC,
I'll have a go at it...

A lot of guys are using the model 91XG UHF antenna with good results. It's offered by a couple of different manufacturers. I don't think it's that big of an antenna but you can decide for yourself. Check out Solid Signal...
http://www.solidsignal.com/
...to get a look at it and many other antennas.

I'm not familiar with your TV market so you may also need an antenna that'll do VHF.

As for the Rad-Shack A/B switch...although I'm not familiar with that model I do know that every time you go through a switch some of the signal is lost.

Distribution amps often cause more problems than they solve. I'd use a mast mounted pre-amp and forget the distribution amp. You want to amplify the signal as close to the antennas as possible. I use a Channel Master 7777 pre-amp with good results.

Check out my "Indoor DTV DXing" post, elsewhere in the forum, to see what can be done with a simple set-up.

I hope this has been of some help.
73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

TomCat4680
04-29-2009, 03:53 AM
Hi TC,
I'll have a go at it...

A lot of guys are using the model 91XG UHF antenna with good results. It's offered by a couple of different manufacturers. I don't think it's that big of an antenna but you can decide for yourself. Check out Solid Signal...
http://www.solidsignal.com/
...to get a look at it and many other antennas.

I'm not familiar with your TV market so you may also need an antenna that'll do VHF.

As for the Rad-Shack A/B switch...although I'm not familiar with that model I do know that every time you go through a switch some of the signal is lost.

Distribution amps often cause more problems than they solve. I'd use a mast mounted pre-amp and forget the distribution amp. You want to amplify the signal as close to the antennas as possible. I use a Channel Master 7777 pre-amp with good results.

Check out my "Indoor DTV DXing" post, elsewhere in the forum, to see what can be done with a simple set-up.

I hope this has been of some help.
73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

I've decided to go with a Radio Shack U75R. average 4.5 out of 5 stars rating among 144 customers.

I don't know which pre-amp is best. I thinking of getting the
Winegard AP 8275 Chromstar 2000 Series VHF/UHF Pre Amplifier (AP8275) at http://www.solidsignal.com/prod_display.asp?main_cat=03&CAT=&PROD=SAP8275.

TomCat4680
04-29-2009, 06:49 PM
Well I just bought the U75R. For some reason the box says it only has a 50 mile range. WTF? The website says 75! Was I ripped off? I haven't put it up yet; I'm having my dad come over to help me install it on Sunday. Will I need a pre-amp to get stations from Detroit (most of them are probably over 45 miles away)

cd637299
04-29-2009, 07:04 PM
Everything's relative, TC. "-mile range" vastly depends on power of the station, antenna height, location, terrain, etc.

Those ads telling you of a "range" can be a tad misleading.

cd

cd637299
04-29-2009, 07:07 PM
To add to the mix, I'll tell you that when I go on my DXpeditions, I use a Radio Shack VU90XR....the "90" refers to the mile range. I set out to try to catch Cuban FM or TV from the FL Keys. Cuban TV stations, and to a greater degree the FM's, do not have near the max power of our stations. The easiest TV stations from there to catch are about 110 miles, and some days reception is peachy, sometimes almost nonexistent.....again, even more-so for FM.

cd

TomCat4680
04-29-2009, 07:16 PM
So do you think I should get a pre-amp? Here's the TVfool info for my apartment. The U75R box says it has an average UHF gain of 7.2 db. Is that enough for ALL of the Detroit stations? I'm most interested in the ones my indoor can't seem to get now (WWJ-TV, WKBD, WTVS, WADL and WPXD), and the ones that come in good except when a car drives by (WJBK, WXYZ, WDIV and WMYD).

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d7f1414683d0b53

Gary Hickerson
04-30-2009, 02:34 PM
TomCat,

I have found, that Radio Shack, almost, always, Overrate, their antennas. Another problem, is, the are not very sturdy. I the 91XG, would be good also the Winegard PR-9032, excellent ant. The CM #777 preamp is excellent also as well as the Winegard AP 8275. The RS preamps, tend to oscillate (not good). Any of the Winegard or CM preamps or ants., are quality stuff!
PCH63
Gary H.

TomCat4680
04-30-2009, 02:36 PM
well too late i already bought it. just ordered a HDP-269 pre-amp too.

NN2E
05-01-2009, 04:02 PM
Hi TC,
Gary and cd have given you good info.
I've seen TV from Mexico on a portable set using a whip antenna. Technically, I could say the whip antenna is "a 1000 mile antenna" and I wouldn't be lying but, I'd be stretching the truth to it's limits.
I'd say, give the Rad-Shack antenna + the HDP-269 pre-amp a shot. Put it up as high, and in the clear, as you can and see how it does.
73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

TomCat4680
05-01-2009, 04:24 PM
Well my pre-amp from SolidSignal.com was just delivered less than 24 hours after I placed my order, so I'm definitely going back to them if I need more accessories. I guess I should have visited their forums too.

TomCat4680
05-05-2009, 11:04 AM
Okay I got the U75R and HDP-269 all hooked up but I still seem to be having the problem of interference when cars drive by. Also some only come in at night. So should I get a higher powered antenna? A higher powered pre-amp? Wait til the new DTV transition date of June 12? I want to watch EVERY Detroit channel 24/7 WITHOUT interference, multipath or digital cliff effect problems.

Just removed switch and re-attached distributor amp. Not much of a change...

Jim Thomas
05-05-2009, 11:57 AM
I'm in a 2nd story apartment and the only window available where I wouldn't be tripping over cords faces east. Also, I'm on a busy road and the signal always drops out for Detroit channels on my directional indoor whenever traffic gets too heavy. Oh I also have the Detroit antenna hooked to a distribution amp.

Help?


Step 1 - Do you have a balcony with your second story apartment?

Step 2 - A second story apartment should be approximately 25-30' AGL and unless that 'busy road' is on a slope that comes up in front of your 'referenced window', shouldn't be the issue of why you are losing signals with increased road activity.

Step 3 - Keep in mind that a distribution amp has dB insertion loss with each connection. That goes for anything you use when connecting cables - splitters, combiners, a/b switches, etc. IF you need to use a a distribution amp, try to use one that is low loss (0-3db). Some lose as much as 8db signal. (That's a killer!)

I have finally found what works for me. I wanted to be able to receive my core group of Denver dtv's, 45 miles south, and a couple network stations in Cheyenne WY, 55 miles north. However, I did not want to use a switch. I wanted them there at the same time. I had to use two dissimilar antennas. I use a CM 4228 8-bay for Denver and an Antennacraft MXU59 Deep Fringe UHF antenna for the Cheyenne stations.

http://www.warrenelectronics.com/antennas/mxu59.htm

There are a few things you need to keep in mind when joining two antenna cables (either with a combiner or a/b switch). To keep things balanced with the incoming signals, the two antenna cables that feed to the combiner, a/b switch, or distribution box, need to be equal lengths. What length? You have to determine that by what is the lowest channel number you receive from either direction. THEN, you have to determine the wavelength of that channel, THEN, make each cable 1/2 wavelength of the number you just deteremined for the lowest channel. :confused: At this point, you may say, BUT I'm using an A/B switch - is that really necessary? It is because the primary signals coming off of the antennas is feeding through those cables to the switch/etc., and if they are not equal lengths, the antennas are not tuned to each other. The other thing is spacing of the two antennas you are using. How do you have the two antennas in relationship to each other? It is recommended that, if vertical, they are one half wavelength apart (the booms), and if horizontal, a full wavelength from each other. If you have two antennas right next to each other, they will interfere with the 'performance' that is necessary to do what they would made to do.

In my situation, I have the CM 4228 (pointing SW) at the top of my mast and the MXU59 (pointing N), lower by 32", which is a half wavelength of vhf 7 (which is my lowest received channel). I continued to have multipath issues so seriously that certain channels were being completely wiped out until I did EXACTLY as outlined above. The information I am giving you is from an antenna installation company that has to do such assemblies for their customers, because they are located in an area where they have multiple TV signals from different directions. Most of their customers do not want to fiddle with A/B switches - they want their channels now! :mad:

I hope this brief tutorial helps.

TomCat4680
05-05-2009, 12:09 PM
The U75R is OUTDOORS on my ROOF. I guess I didn't make that clear. I just put away all of indoor antennas, I don't seem to need them any more.

Okay removed the distributor amp too...

I updated my signature to clear up any further confusion...

Jim Thomas
05-05-2009, 12:56 PM
Also, if you have not already, you might want to check out the threads for your local area on the AVS Forum. You can subscribe just like this Forum, then post questions or comments.

For Flint, the link is...
http://www.avsforum.com/avs-vb/showthread.php?t=250654

For Detroit....
http://www.avsforum.com/avs-vb/showthread.php?t=453486

TomCat4680
05-05-2009, 05:15 PM
Okay here's the percentage readouts: May 5 at about 4:00 PM per AM21 (all highest it received)

WJBK 65 %
WDIV 59 %
WXYZ 75 %
WMYD 73 %
WPXD, WADL, WKBD and WTVS no signal
WWJ-TV 49 %

I'll check again tonight and early tomorrow morning as a comparison...

So how do I get these up to the to the 85-95 % range?

Mike-CT
05-05-2009, 07:20 PM
I want to watch EVERY Detroit channel 24/7 WITHOUT interference, multipath or digital cliff effect problems.

After reading this thread one thought comes to mind: You may not be able to. Too many variables.

BTW, I plugged my zip into tvfool.com and the results gave me a couple of laughs. Don't make something out of tvfool that it isn't. It's just a guide...not a bible.

A preamp needs a signal to amplify. Poor signal, poor amplification. And a digital signal is more fragile than an analog signal. I think you're finding that out.

Good luck, though.

Jim Thomas
05-05-2009, 09:36 PM
I agree with Mike 100%. The one thing you can do right now is be patient until the final June 12th analog cutoff. Once the analog signals 'clear the air', you'll have a much better idea what you can and cannot do.

One thing an antenna amplifier does that we might tend to forget about, especially when we're trying to get maximum mileage out of our DTV signals - it amplifies ALL of the TV signals that are present - ANALOG and digital. Even if the DTV tuner can't do anything with analog signals, it still "see's" them and that can also be seen as multipath interference. If you have any strong analog signals that are present, they can get in the way of the DTV tuner doing its job. ALSO - all of your local/semi-local DTV channels may not be running at full power yet - until June 12th. I am not familiar with your local situation and you may want to research that - a determination of who is full power and who is not. Again, for those that are not, you will have to be patient.

FWIW....

cd637299
05-05-2009, 11:17 PM
Outta curiosity, TC----does CBET have a digital ch? One would think that the Detroit market would pressure CBET to do so.

If so, have u seen it?

cd

TomCat4680
05-05-2009, 11:20 PM
Outta curiosity, TC----does CBET have a digital ch? One would think that the Detroit market would pressure CBET to do so.

If so, have u seen it?

cd

CBET is considered the "Windsor market" so only cable customers get it. I don't know if its digital yet or not, I can't get it here I know that...

TomCat4680
05-05-2009, 11:22 PM
I agree with Mike 100%. The one thing you can do right now is be patient until the final June 12th analog cutoff. Once the analog signals 'clear the air', you'll have a much better idea what you can and cannot do.

One thing an antenna amplifier does that we might tend to forget about, especially when we're trying to get maximum mileage out of our DTV signals - it amplifies ALL of the TV signals that are present - ANALOG and digital. Even if the DTV tuner can't do anything with analog signals, it still "see's" them and that can also be seen as multipath interference. If you have any strong analog signals that are present, they can get in the way of the DTV tuner doing its job. ALSO - all of your local/semi-local DTV channels may not be running at full power yet - until June 12th. I am not familiar with your local situation and you may want to research that - a determination of who is full power and who is not. Again, for those that are not, you will have to be patient.

FWIW....

Yeah you're probably right. I'll wait until after June 12 to see what I do and don't pick up then. I know WKBD's analog signal is WAY stronger than its digital signal right now...

Robert Grant
05-06-2009, 01:06 AM
Outta curiosity, TC----does CBET have a digital ch? One would think that the Detroit market would pressure CBET to do so.

If so, have u seen it?

cd

NO

And, sadly, may never be. It has, however, been given a reprieve from a proposed budget cut that would have shut it down altogether, so it should be available as analog 9 until August 2011.

One other note - the CBET of today is not nearly as strong in Michigan as it had been years ago. Many years ago (I think it was in the late 1990's), CBET left their old tower (it was actually an enormous tubular mast) that was right up against the Detroit River and moved to a shorter tower near McGregor that is shared with CICO32 and CBEFT.

cd637299
05-06-2009, 02:27 AM
ah----I see, said the blind man.

cd

TomCat4680
05-06-2009, 12:16 PM
I'd like some Canadian channels on DirecTV. There's like 50 Mexican / Latino ones. Doesn't seem fair...

cd637299
05-06-2009, 03:50 PM
Well, I dunno....if you ever get to see SCTV (the comedy troupe)'s jab at Canadian TV, if it is really like they portray it, welllllllll.....

It's a hilarious bit. Supposedly in this series of skits, the CBC took over SCTV's facilities (maybe it was a strike by SCTV). They did a spoof of CBC's "Headline Hunters" (similar to What's My Line)....boy was that bland....but funny.

Apologies to our Canadian friends here....but SCTV IS Canadian.... :)

cd

TomCat4680
05-06-2009, 03:54 PM
My favorite current Canadian show would have to be Red Green. That guy's freaking hilarious. You Can't Do That On Television was my favorite as a kid...

Anyways, back on topic. Solidsignal says I need a HD9032. To me its looks just like the U75R. They were acussing Radio Shack of exaggerating their own stats. Maybe they're doing the same...?

cd637299
05-06-2009, 04:31 PM
My brother loves Red Green...He got a couple of DVDs of it for his birthday, I think.

BTW on that SCTV thing....to give you an idea....the Headline Challenge mystery guest was silhouetted behind a translucent door. The host told the panel to put on the blindfolds. The clue was "He's a popular Canadian actor." The first panelist said sumpn like "Hmm, a popular Canadian actor.....(pause).....I'll pass."

If that wasn't enough....when the panel seemed stumped, the host said, "OK we will show everyone who our guest is. And Panel, take off your blindfolds....and we will CONTINUE THE QUESTIONING with Philip Marks." How obscure can a guest be???

Most effective was, that there was NO laugh track here. Made it sound serious. Quite effective. That "continue the questioning" still has me LOL.

cd