The Official AVS Antenna and Related Hardware Topic! - Page 63

Thanks for this link! It verifies my worst fears - I'm getting FM interference on Channel 8! And it's going right through the FM trap on my preamp! My analog picture strongly resembles the third one on his FM page.

The "dark secret" of FM traps is that they usually don't work below 92Mhz (my problem station is at 91.7) I'd pay good money to have that interference go away. (They'll be on digital 41 until the shutoff, and then they'll move back to channel 8.)

Doable? Yes. Cheaply? No.

The best thing to do would be to raise your antenna above the trees - 10' above them, if possible. Don't worry about ones more than 200'-300' away. Just get above the ones that are close in.

The second best thing would be to try a different style of antenna like the AntennasDirect DB8. The bowties do tend to do a little better in treed in areas.

The perfect filter option isn't going to be cheap, though you could try Jointennas designed for channels 17 or 16 and see if they work. (They have overlap in about 2 channels in each direction, and since you have nothing below 19 on UHF, they might work out okay.) Individual channel filters with sharp cutoffs are usually $200+, but if that's Canadian dollars...

I use the FM trap in my 7777 and in *addition* put one in-line right before the TV (the one made by Winegard). It makes a definite difference without them both in. The other thing you could do (if you don't need low band) is to use the hi port of a hi-lo diplexer which will filter everything below channel 7 (including FM). A good and cheap one made by PICO at http://www.picomacom.com/specs/pico/C/C24.pdf
I think it only passes DC on the lo port so you'll have to put it last or put it on the antenna.

I've heard a few different opinions on joining two different antennas (2 UHFs pointed in separate directions and located on different masts). I've heard I can simply use a splitter only used in reverse, I've read about using a combiner (like the one at www.antennadirect.com), and also about using a A/B switch. There is a big price difference between the splitter (~$4-$8) and the combiner($16 at antennadirect), can someone tell me which one I should be using?

Also, after reading the descriptions, it looks like the CM 7775 would be my best option for the amplifier (since I am only using UHF antennas). Should I consider a different amp.?

Thanks for helping ignorant souls like me!

You cannot predict the results of combining two UHF antennas pointed in separate directions using either a simple splitter or a combiner - I'd guess that 75% of the time, it doesn't work for digital reception. The only way this works reliably is if you have *ONE* station in a different direction from all the others and you use a product from Channel Master called a "Jointenna." An A/B switch would also work well, but isn't quite as "automagic."

I don't recommend the 7775 to anyone at this point, as some digital signals will move back to VHF frequencies in a few years, and you'll need a new preamplifier when that happens (the 7775 does not pass VHF.) I'd get a 7777 instead.

When will this move be taking place? Which channels will be affected?

Thanks sregener. I tried a CM 4221 4 Bay, and it performed worse than the Yagi. I guess I could try a 4228 or the DB-8, but I just don't think I will see much difference. As far as the trees go, I have pines in front of the house that are 60+ feet. I doubt my wife would allow either a 70' antenna mast, or the use of a chainsaw :-). I looked at the Jointennas listed on the CM website, and all I found in the UHF range were 3 models, the closest one to 19 was the 0585-1 for channels 14-29. I don't think that would work since it would pass 19, 20, 21, 25 and 27 from the second antenna. Atlanta is one of the 10 DMA's that D* is launching HD local-in-local, so I guess I might just have to pass on CBS until then.

Whenever analog shuts off. Who knows when that will be but it will happen sooner or later.

If you have analog stations in the 7-13 range chances are pretty good they'll want to go back to their analog channel number. High VHF is prime real estate as the same coverage area can be had for less power.
You can find out your local stations channel election application result at http://www.tvradioworld.com/region1/
Click on your state, area, then the analog station in question's "complete FCC data" then go to "application list" and look for the "FRECT" application which should indicate the station's choice in the first round channel election.

Article on DTV channel selection:

http://www.tvtechnology.com/features...04.06.05.shtml

Ron

Thanks! That helped, the station I was especially interested in (WRTV out of Indy) put their UHF station (25) as their first choice.

A model 0585-1 Join-tenna has separate bandpass and band reject traps that are tunable to any channel from 14-29. The bandpass width is several channels wide. They typically pass two adjacent lower channels and two adjacent upper channels unscathed, and taper through the third channel away. In other words, if you have one tuned to channel 23, it will pass channels 21-25 like a sieve, beat up channels 20 and 26, and evenly reject 14-19 and 27-69 to full depth, which might be around 20dB.

The band reject circuit on the "All Channels" port is only slightly narrower. If a Join-tenna is tuned to reject channel 23, then it will also wipe out channels 22 and 24, but taper fairly sharply through channels 21 and 25 and not impede 20 or 26 at all. In other words, the reject or notch filter is a couple of channels narrower than is the bandpass filter. With a spectrum analyzer, you can fudge the trap edges by about one channel, but you can't make the pass band or notch bands any narrower.

The other sucky thing about Jointennas is that they are in a unshielded plastic cases, and if you are real close to a channel you are trying to couple, the ingress can wreak havoc on the waveform of the strong, pass-band channel.

I just read f300v10 's earlier post. He seems to need channel 19 from a different vertical plane, but must keep channel 21. He should order a Join-tenna tuned to channel 20. It will pass 19 and 21 from one antenna and couple them with the rest.

If these antennas are on the same mast, then he probably should try to keep the coax lengths to the Join-tenna identical, so that any unintended passed signal is in phase with the intended signal. That assumes that neither the band pass filter or the band reject filter shift the phase of any signals impressed upon them.

On the other hand, it is unlikely that the optimal location for the channel 19 antenna is on the same mast as the other antenna. If a better spot is found elsewhere, then there is no benefit to keeping the cable lengths equal.

I don't know why more people don't just use infrared A/B switches. There are models for $40 or less that can be toggled by any remote control, either by programming it to respond to an infrequently used button, or some other respond to any long duration infrared data stream.

I agree that the A/B switches seem to make the most sense for people who watch "live" television. But that number is dwindling as DVRs become more popular.

There also is the trainability factor. For me to explain how to watch television to someone visiting my house takes at least five minutes. And I still come home to find components (including the television itself, with a black screen) left on...

AntAltMike, thanks for the input. The antennas would indeed be on the same mast. The reason I don't just use a switch, is that I have an HR10-250 HD TiVo, and watch almost all my programs recorded. Unless I have an automated way of switching the antenna inputs it wouldn't work.

To re-state what I am trying to do, I would like to get channels 10, 20, 21, 25, 27, 39 and 43 from my current primary antenna, and 19 only from one mounted 4 ft. higher. I have tried positioning my current antenna at 10 different heights and not one currently works for all the above channels. The current position gives me all but 19 perfectly, but next to nothing on 19. The good position for 19 gives bad 10, 20, 25, 27 and 39. 21 and 43 are great at both positions. If I am reading your comments correctly, I could get a 0585-1, tune the band reject to 20 for the primary and join the secondary? That should give me 19, 20 and 21 from the secondary and the rest from the primary? I think I might lose 20 in that case, but I would be willing to trade 20 for 19. Am I reading this correctly? Also do I order the Join-tenna pre-set to 20, or can I adjust it after I get it?

Thanks

You've got it. The Join-tennas are normally ordered and shipped pretuned to the ordered channel. It would be almost impossible for you to further "tweak" its tuning without using a spectrum analyzer, but you shouldn't need to do that with the three insertion channels being adjacent to one another.

Thanks AntAltMike. Would I be better off getting the JoinTenna set to band reject channel 17 as sregener suggested, which should let 14-19 pass, lower 13 and 20 and stop 2-12 and 21-60? I think that would be closest to my original goal of 19 only off the secondary antenna.

Also, the JoinTenna has 2 types of filters a band-pass and a band trap? If I order the unit set to channel 17, will that be the channel setting for both filters? And one last question, is the JoinTenna suitable for outdoor installation?

Thanks for all your help on this. It's knowlegble folks like you that make this forum such a great resource.

You may not have to use the jointennas.Just combine the two antennas using a splitter used backwards and equal length feedlines.You might get lucky:-)

Well, shoot! Why didn't I think of this sooner?

Get a second identical antenna and combine the two like MAX HD says. If the antennas are identical and the feedlines to the splitter are exactly the same length, you've got yourself a vertical stack and it should work just fine. (Point the antennas in precisely the same direction, too.)

If it doesn't, you could still buy a Jointenna.

But I'm betting that a vertical stack hooked up like this would work great - and it might even improve reception on other stations you're not getting.

OK, I will give that a try. If it doesn't work, I will then try the jointenna. Thanks again for all the help.

Hi

New member here. I've been reading through this thread trying to figure what is the best antenna to use. Im considering an indoor antenna as i only live like 4 miles away from the stations. Zip is 60616. I read the radio shack or silver something is good. Anyone could help me with clearer info in which is the best indoor antenna, and what model it is. ThANKS A LOT

http://www.zenith.com/sub_prod/produ...?cat=49&id=131

http://www.radioshack.com/product.as...%5Fid=15%2D624

Since there is one VHF station in the area now and a couple more switching to VHF in the next couple of years, you might want to go for a combo antenna such as http://www.radioshack.com/product.as...1880&hp=search

A UHF only antenna may work for VHF since the distance is so small though. A cheap rabbit ear + UHF loop could do the trick too.

Sregener-
The stations you're picking up with the XG91, how are they rated on AntennaWeb? Are they even rated?

violet - uhf KMWB 23 WB MINNEAPOLIS MN
violet - vhf WKBT 8 CBS LA CROSSE WI
violet - uhf WHWC 28 PBS MENOMONIE WI
violet - uhf WFTC 29 UPN MINNEAPOLIS MN
violet - uhf WEUX 48 FOX CHIPPEWA FALLS WI
violet - uhf KXLT 47 FOX ROCHESTER MN
violet - uhf KYIN 24 PBS MASON CITY IA
violet - uhf KSTC 45 IND MINNEAPOLIS MN
violet - uhf KSMQ 15 PBS AUSTIN MN
violet - vhf KTTC 10 NBC ROCHESTER MN
* violet - uhf KTTC-DT 10.1 NBC ROCHESTER MN

As you can see, Antennaweb (no buildings, multiple story structure) expects me to receive one digital station, and that's with the largest antenna and preamp available.

I had a Winegard HD-7084P on my roof (single story), with a 28db UHF preamp (Winegard AP-8780) before my current tower, and I got KSMQ, KTTC and KXLT digitally 24x7. Obviously, they still come in with the 54' tower and the 91XG.

Thanks for the info. I'll have to give the antenna a long look, if i decide to attempt some violet S.F. channels.

I am moving to Edgewater, MD (Just West of Annapolis) in a couple of weeks and am wondering if anyone in the Annapolis/Edgewater area is getting DC channels OTA, and if so, what info they could provide regarding their setup regarding the type of antenna they are using, the type of mount, etc.

I am moving into a community with a HOA, and while I know they are not within their rights to do so, their rules place restrictions on antennas, etc. I will already be installing a Direct TV dish, and I'd rather not throw a huge antenna on the roof as well (and thus piss off the neighbors before I even get to know them!) so I am hoping I can get away with an attic install . . .

Any Annapolis/Edgewater/Davidsonville people here who can give me some OTA tips?

Thanks in advance!

That area would appear to be covered by the D.C./Baltimore thread http://www.avsforum.com/avs-vb/showt...44#post5288144

Thanks, Pat. I posted this information on that board as well. Hopefully I will get a response soon!

How are the Terk HDTV-S antennas? Was thinking of getting one and mounting it on the roof.

Sorry. Terk has a reputation for being overpriced and/or underperforming.