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Questions on Rooftop Antennas

captouch

captouch

Addicted Member
I have an old rooftop antenna on the top of my house, used to get over the air HDTV.

It looks like this:
Rooftop_Antenna.jpg


I'm wondering - do new antennas do a better job at getting stronger reception vs these old ones? Or are they basically the same.

This one has to be taken down temporarily for a termite fumigation and I'm not sure whether to try and be careful with this one (to avoid damage) and put it back up, or just get a new one that's better.

Thanks.
 
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It looks basically the same as mine and I purchased it about 3 years ago. I get OTA HDTV w/great picture quality. I see no difference in the one in your picture than the one I put up.
 
The one you have may be better than new ones. As far as digital, RF is RF. Since it's down, clean up the contact points that connect back and forth to the elements and other electrical connections. A lot of the new supposedly "digital" antennas assume there is no VHF, only UHF, or may have only the High 7-13 VHF channels. With future "repacking" of the TV channels by the FCC, some channels may eventually go to Low VHF (2-6) which that antenna will do well. So I would definitely clean it up and keep it in use, look at the coax and maybe replace it with some good RG-6 quad shielded coax, and use compression F-connectors and you'll be in good shape.
 
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I have had one like your picture for 10+ years and it made the digital transition perfectly!

I would hang on to it.
 
Thanks guys. I guess I'll try to climb up there this afternoon and take her down myself. If it's worth saving, I don't really trust the fumigators to keep such a vintage piece intact.
 
Wish I had one like that. Mine half that size and I hide it under the roof of my porch for FM... Apt living stinks!
 
You might consider this. Replace the coax with 300ohm flat lead. I replaced my coax with 300ohm flat lead and gained at least 10dB in signal strength.
Look on eBay and you can get various lengths. I think I bought 75ft for about $15. Hell, for what I save in cable bills I could buy 100 miles of it!
AND a mile of antennas!
 

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Ed in Tx said:
The one you have may be better than new ones. As far as digital, RF is RF. Since it's down, clean up the contact points that connect back and forth to the elements and other electrical connections. A lot of the new supposedly "digital" antennas assume there is no VHF, only UHF, or may have only the High 7-13 VHF channels. With future "repacking" of the TV channels buy the FCC, some channels may eventually go to Low VHF (2-6) which that antenna will do well. So I would definitely clean it up and keep it in use, look at the coax and maybe replace it with some good RG-6 quad shielded coax, and use compression F-connectors and you'll be in good shape.
Click to expand...

Agree 100%. I had one of these type yagi antennas at my old house and it did a fine job on HDTV. Replacing the cable is a must. Plus, as an extra bonus, this might also do well on local FM reception. Unfortunately, fewer and fewer full band models are available, so if it's in good shape, keep it.
 
dosmalo said:
You might consider this. Replace the coax with 300ohm flat lead. I replaced my coax with 300ohm flat lead and gained at least 10dB in signal strength.
Look on eBay and you can get various lengths. I think I bought 75ft for about $15. Hell, for what I save in cable bills I could buy 100 miles of it!
AND a mile of antennas!
Click to expand...

You still have to transform it from 300 Ohms balanced to 75 Ohms unbalanced coax to hook it up to the TV with its F-connector. What are you using to do that? (Unless you're talking about an older pre-1975 or so TV with the two-screw 300 Ohm antenna connectors.) The 300 Ohm flat will have somewhat less loss at UHF frequencies than RG-6 coax, but can be more susceptable to interference, and needs to be kept away from anything metal like rain gutters, and standoffs used to keep it away from the mast to maintain the balance between the two conductors. The RG-6 is good because it has minimal loss and you can route it anywhere and tape it to the mast with no effect.
 
I climbed up there, but it's pretty windy and no extra pair of hands, so after noodling on it for a bit on the roof, I decided it wasn't worth my breaking my neck/back trying to do it myself. Hopefully I can be there when they take it down to set it down gently.

It's currently using a coax - RG6 most of the way from the antenna to the house - from there, I have it going into a splitter/amplifier and 2 of the outputs are used for FM tuners and two for HDTV.

I'll keep my fingers crossed they don't break it.
 
Ed in Tx said:
You still have to transform it from 300 Ohms balanced to 75 Ohms unbalanced coax to hook it up to the TV with its F-connector. What are you using to do that? (Unless you're talking about an older pre-1975 or so TV with the two-screw 300 Ohm antenna connectors.) The 300 Ohm flat will have somewhat less loss at UHF frequencies than RG-6 coax, but can be more susceptable to interference, and needs to be kept away from anything metal like rain gutters, and standoffs used to keep it away from the mast to maintain the balance between the two conductors. The RG-6 is good because it has minimal loss and you can route it anywhere and tape it to the mast with no effect.
Click to expand...

I'm using a 300/75 Ohm transformer just on the television end. I was able to get around that part up on the antenna end just by splitting the flat lead and going "old school" on the connections.
The flat lead was better for my set-up all the way around. Actually, I was surprised it was still available but I stumbled on to some NOS Philips from a seller on the bay and I bought 2 rolls so I'd have more if and when I ever needed it.
I think the biggest cost of the whole set up was the mast which was in 5 ft section from Radio Shack and was close to $15 a section (!)
But...even all that has paid for itself quite a few times over since I went OTA.
It's been over 2 years and I've never looked back:banana:!
 
dosmalo said:
You might consider this. Replace the coax with 300ohm flat lead. I replaced my coax with 300ohm flat lead and gained at least 10dB in signal strength.
Look on eBay and you can get various lengths. I think I bought 75ft for about $15. Hell, for what I save in cable bills I could buy 100 miles of it!
AND a mile of antennas!
Click to expand...

This should not be - something wrong with your coax (wrong type with high loss) or with the balun transformer at the antenna end. We would never use twinlead - subject to degradation if not spaced away from metal mast, potential interference pickup. You should get the same 10 dB improvement with the proper coax.
 
Well, it very well may have not been proper to begin with. it was the crap that the cable company left when I kicked them to the curb. No telling how old it was but the twin lead gave me at least a 10 dB increase in signal and whereas figure-ers may lie, figures don't. That coax went to the curb too.
I only have broadband cable internet w/no TV (of course)and every time they roll a truck for me because of funky internet probs they change the drop coax and it's something different every time. I've had big and fat (actually about the size of my index finger) and then something smaller and orange colored and a couple of different ones in between. My ISP is CRAZY!:screwy:
The repair tech comes in the other day and actually TOOK the cable Motorolla surfboard modem THAT I HAD PAID FOR AND OWNED (no monthly rental) and replaced it with a new Motorolla SB6141!:jawdrop:
Walked out with MY modem and left.
I'm waiting for my next internet bill to see if they're planning on charging me a monthly rental fee. If so, a pow-wow will insue.
But, long story short, I like the twin lead.
 
Slightly off topic, but can anyone advise how the multiple screens of the co-ax should be connected, that is at the aerial end, and the equipment end...
 
Hyperion said:
Slightly off topic, but can anyone advise how the multiple screens of the co-ax should be connected, that is at the aerial end, and the equipment end...
Click to expand...

Sounds like you are using multishield cable - perhaps it has twisted braid as well as foil?

With Coaxial cable, there's basically only 2 connections - the center conductor (signal), and the shield/braid (ground). Center conductor comes out the center of the F connector, shield gets around the outer edge of the connector and gets crimped by the ring.

If your antenna and TV have twin screws to connect to (usually for twin lead design), you need a Balun (Balanced-Unbalanced) transformer to convert between your Coax (75 ohm) and those old-style flat wire connectors (300 ohm).
 
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I was thinking more when you have a co-axial cable with an outer screen and an inner screen AND an inner (centre) conductor. Just wanted to know the recommended method of utilising the fact that you have 2 layers of screening at your disposal.

EDIT: - Got it - http://www.swhowto.com/CoaxStrip.htm
 
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Right replacement part???

Well, they did break something when they removed the antenna. :( I think it's minor though.

What broke is the old looking part that has two leads (connects to the antenna and one of them is broken off in the picture below) and then leading to a coaxial connection.

I bought what I think is the equivalent part that seems to have the same connections: The part (as I bought it) is called a matching transformer and the back shows a connection from a rooftop antenna (300ohm) to a coaxial cable going into a TV (75ohms).

photo_23.jpg


This part should be a fine replacement for the broken part, right?
 
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Yes that should do it. Matching transformer, or balun transformer ( balanced-unbalanced).
Looks like the old one was pretty much corroded anyway. I would put a dab of silicone grease in the coax fitting when attaching the cable. F connectors aren't very water tight.
 
Thank you sir! Appreciate it and you're right, the old one was pretty shot anyway. Maybe I'll get better reception! :)
 
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