Rooftop Antenna

[Tivoman44]

I just bought a house in the Greenfield/Greendale area.  The house has a rooftop antenna installed, unclear as to how old it is.  It has a coax cable fed down into the basement.  I tested it out using a small tube TV with an Insignia converter box connected to it.  I did a channel scan and it only found about 15 channels instead of the normal 30 or 40 something if you count the sub channels.  Off the top of my head it found Ch 4, 18, 24, 36 and 58.  All channels found the picture came in well, had the TV on for a few minutes, zero pixelation, and the signal meter, while not 100% was into the high 70s and 80s.  

It's clear that it is a UHF antenna.  I tuned manually to channel 6, and some others and it was a black screen with no signal.  Before I had a new antenna installed, any suggestions as to why not all channels were picked up?

[duncantuna]

I'm not a signal engineer, but I'd suggest it is NOT a UHF antenna as you wrote.

Nearly every Milwaukee digital channel is in the UHF band .. so if you're not receiving many channels, it's probably because only the strongest UHF signals are getting to the antenna, which is VHF.

[budda]

If you have a directional ant., then you need to point it at say 1 or 2 o'clock , given that 12 is direct north. This being the case. That would explain the channels, or lack of. JMO

[Tivoman44]

Well rabbit ears make it easy to see if it has the UHF loop or not.  When I climb the roof in a few days, what am I looking for to see if it is UHF.  

It looks like it is pointing 1 or 2 o clock already.

[Jimboy]

Post a photo.........

[Bebop]

I"m near Southridge. I can pickup all these channels:




If you can't pickup channel 10. It's a good chance it's a UHF only antenna.

[Nels Harvey]

Well rabbit ears make it easy to see if it has the UHF loop or not.  When I climb the roof in a few days, what am I looking for to see if it is UHF. .

I would suggest adding an in-line preamp and new RG-6 cable to the antenna that you have now.  After a re-scan, if you still don't receive all the stations here in Milwaukee, then replacing the antenna itself probably is necessary.

One of the best antennas for UHF reception is the Channel Master 4228.  It's design will permit reception of Ch. 8, which is the actual channel WMVS Ch. 10 is transmitting on.

Just remember, with the exception of Ch. 18 in Milwaukee, all of the other stations transmit on a different channel than the one associated with their identity.

[Tivoman44]

I will be taking a picture tomorrow and posting it.  

Dumb question, how do I upload the photo to a post?

[ArgMeMatey]

I will be taking a picture tomorrow and posting it.  

Dumb question, how do I upload the photo to a post?

You have at least two options.    

First option:  
Use IMG tags to insert photos from a third-party site such as photobucket.  That gives you more control over the photos and it will load them with the post.

Second option:  
1.  Hit the quote or reply button.  
2.  Enter your text in the "Reply to thread" window.
3.  Scroll down to the "Additional Options" section.  
4.  Look in the "Attach Files" section.
5.  Press "Manage Attachments"
6.  You can probably take it from there, but if not post back.

[Jimboy]

What's with the multipath maker behind the Digitenna?

[ArgMeMatey]

What's with the multipath maker behind the Digitenna?

I don't want to threadjack but you can see the history here ...
http://www.milwaukeehdtv.org/forums/showthread.php?t=9147

[Tivoman44]

Here are the pictures.  Do I need a new antenna?  

Also I uploaded a picture of a Jack in my living room, two coax and a cat5 ethernet, is that a Uverse hookup?

[ArgMeMatey]

The box mounted on the mast below the antenna is probably a preamp.  Have you inspected it?  Is there a power supply / distribution amp in the basement or attic?  

While you're up there, take the cables off of it and use some emery cloth to clean the center conductors.  

It could also be a splitter/combiner ... etc.  

If you don't know what it is, and there is no corresponding basement/attic box, I would go up there with a barrel connector and use it to take the box out of the line, then see if reception is better.

[Jimboy]

I'd replace the antenna.

I currently use the older version of the Channel Master 4228 in a garage attic on the south side of Oak Creek with stellar results. Warren Electronics has the newer version available http://www.warrenelectronics.com/antennas/4228HD.htm

Also (it's made in Wisconsin) I'd suggest trying one of the outdoor versions of the Digitenna.  http://digitenna.com/products
I would try the DUV Deep Fringe. It's always better to capture enough signal in the first place then to find it in the noise floor with a preamp.

[Tivoman44]

Thank you all for your help.  I may post a few more questions in the coming days/weeks.  

I have not been on the roof as of yet and I wondered what that box is as well.  I think it may need a new coax cable as well to be fed down into the rooms.  Thank you for the links to the website.  I think I may just have to buy a new one.  

In addition to the cost of a new antenna, does anyone know of a general labor cost it would take to install/ground a roof antenna?  And then to split the signal into different rooms?

Lastly, when you say preamp, is that basically something that is the opposite of an amplifier, where if an antenna pulls a signal in too strong it basically turns down the signal?