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Identify my existing roof Antenna

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Identify my existing roof Antenna

Postby tvwatcher on Thu May 01, 2008 8:15 am

Long time gawker of thios forum, first time posting.

I recently moved into a home not wired for cable or Sattelite but that has a roof antenna. Can someone tell me from the picture attached if they can tell if it is a VHF, UHF, or combined antenna. My plan is to pull available HDTV OTA signals from it and use it alone or by joining it to a second antenna that contains the band that this may be missing.

IMAGE_246.jpg
Photo of Roof Antenna
IMAGE_246.jpg (252.01 KB) Viewed 1302 times


Thanks for all your help.
David

tvwatcher
 
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Re: Identify my existing roof Antenna

Postby SWHouston on Thu May 01, 2008 10:56 am

tvwatcher,

It kinda looks like the HD7###P Series from Channelmaster, not sure though.
Check out.....
http://www.winegard.com/offair/vhfuhf.htm
ans see if you agree. Might help if you measured the Boom length where you could make a more speciffic ID.

Some other points:
I'd get rid of that Twinlead and get some Coax on it. If it doesn't work you can always use the new wire on a new antenna.
Be careful about using two Antennas unless you just have to.
Looks like the one you have may do VHF and UHF, try hooking it up, and see just what it will do !
Drop by one of the Antenna Locators, and make sure you're online with a good Xmitter.

Hope this helps

Have a good Day ! :)

SWHouston
 
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Re: Identify my existing roof Antenna

Postby hdtvlabs on Thu May 01, 2008 3:55 pm

Ok, this is a combined VHF/UHF antenna, but I don't think it's Winegard HD7xxx

I'd get rid of that Twinlead and get some Coax on it.


Though I agree coax is a better solution, one can not simply replace a 300 ohm twinlead with a 75ohm coax, that would cause antenna/cable impedance mismatch and worsen the reception, so be careful there.

hdtvlabs
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Re: Identify my existing roof Antenna

Postby sykes on Thu May 01, 2008 6:22 pm

As far as I know this is a VHF antenna and I don't think that you can do what you're planning because there might be an incompatibility problem. I'm not quite sure because I've never had such an idea. I would really want to find out if it works.

sykes
 
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Re: Identify my existing roof Antenna

Postby SWHouston on Fri May 02, 2008 3:45 am

hdtvlabs,

Yur RIGHT, but as old as that thing looks, probably Lamp Cord would work on it ! :lol:

Have a good Day ! :)

Sorry David, but it does look like it's seen better days ! :P

SWHouston
 
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Re: Identify my existing roof Antenna

Postby tvwatcher on Fri May 02, 2008 5:51 am

When you say "Drop by one of the Antenna Locators, and make sure you're online with a good Xmitter." I know where the transmitters are, they are at the Empire state building in New York City - The question is on that antenna, which way is up so to speak. How do I "aim it" which end of that is the front, etc...

Thank for all your responses, etc...

As far the coax vs twinlead goes, I do use a balun to convert the twinlead to coax about 10 feet after it comes into my house.

tvwatcher
 
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Re: Identify my existing roof Antenna

Postby hdtvlabs on Fri May 02, 2008 7:59 am

How do I "aim it" which end of that is the front


IMAGE_246c.jpg
IMAGE_246c.jpg (79.21 KB) Viewed 1246 times


The red arrow should point to the towers.

hdtvlabs
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Re: Identify my existing roof Antenna

Postby SWHouston on Sat May 03, 2008 7:06 am

David,
hdtvlabs has identified the front (point toward Xmitter) end of your Antenna, now...

Without an ID/model, where you can look up the specs for range, you're just going to have to do "trial n error".

Do a "look up" of the available Xmitters, using the distance in miles, that you are from the ESB. Print it out !
Hopefully, the Antenna is hefty enough to make the distance, it sorta looks like it's medium range, which should get you 30 miles or so.
Given the "field of view" of most Antennas like yours, pointing it upward won't be necessary, but, direction/Azimuth WILL!
Check your printout for direction/Azimuth, if there are several Xmitters, pick the one in the middle of the group.
Got a Compass, USE IT, and make sure that the Boom of the Antenna, is right on line with the ESB. (like shown above, narrow end toward ESB)
Keep in mind, you need to back off about five or so feet from any Metal surface/parts, or it will effect the direction of the Compass Pointer.
Now, crank the system up, do an Autoscan, and see what you got!

Now, check out what you got, to what's out there. Note where the Xmitters are placed on the Printout.
IF you aren't getting ones that you want, see if they are either right or left of the direction you Pointed to, and move the Antenna A LITTLE !!!
The farther you are away from the Towers, the MORE effect left/right movement will have.
At 30 miles, just 1° of Azimuth change, will be several thousand feet, BUT, the Field of View of your Antenna, will allow that.
Keep in mind, what you add to one side, you take off from the other, you only got so much "window" on the Antenna.

Ok, just in case you took offense, I was just kidding about your Antenna in my previous post. I enjoy some frivolity (within reason) when Posting, and don't mean to make anyone mad. Fact is, I enjoy making what I got work, and it's specially gratifying when it's old, and you make it work good. I'm a died in the wool Gadgeteer, and am pretty sure that old piece will probably make the trip, with some TLC.

Tip:
I haven't had much luck mixing Twin Lead and Coax. If I were you, I'd take that Balun and Coax all the way up to the Antenna, and just get rid of the Twin Lead compleetly. Given that most of our stuff isn't all that old, a good bet is that you can use 75 ohm all the way on it, and get a better signal strength.

Remember, we're doing Digital here, it's not like Analog where you could "barely" pick up a Station. Digital stations will either be there or not, there's very little room for error. Most times when you have sound drop out or pixelization, it's cause the Xmitter isn't strong, and less likely that you're off center with it.

Again I must appologize, i may have gone into some very basic detail here, much of which you may already know. SO many people read these Posts, and those have varying degrees of ability and knowledge, that i find that a few extra words just to make sure, are well given.

Hope this helps, and keep us updated on it !

Have a good Day ! :)

SWHouston
 
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Re: Identify my existing roof Antenna

Postby tvwatcher on Sun May 04, 2008 6:08 pm

Thanks to all for the detailed info. I am getting tons of HD stations, and loving every minute of it! I hope to be able to help someone else out in the future the way you all helped me out.

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