RCA Multi-Directional Flat Antenna Designed for Pinpoint Pickup of Free Over-the-Air Digital TV Signals

This forum is for the purpose of providing a place for registered users to comment on and discuss Bulletin postings.
Post Reply
Shane
Publisher / Author
Posts: 1734
Joined: Fri Oct 20, 2000 5:01 pm
Location: Xenia, OH
Contact:

RCA Multi-Directional Flat Antenna Designed for Pinpoint Pickup of Free Over-the-Air Digital TV Signals

Post by Shane »

Viewers looking for an alternative to soaring subscription TV bills should consider pairing a digital TV with a new RCA Flat Antenna designed to pick up more channels than a traditional "rabbit ears" antenna. Local broadcasters are now sending multiple digital TV channels to supplement their main programs, including informational and live radar and weather forecasts available at the touch of a button - for free!

In addition to receiving pristine uncompressed digital TV signals...

[url=http://www.hdtvmagazine.com/news/2008/07/rca_multi-directional_flat_antenna_designed_for_pinpoint_pickup_of_free_over-the-air_digital_tv_signals.php]Read Bulletin[/url]
lmarks
Member
Member
Posts: 25
Joined: Wed Dec 07, 2005 11:06 am

RCA Multi-Directional Flat Antenna Designed for Pinpoint Pickup

Post by lmarks »

New, better antennas should be coming along. There are two factors that will be changing next February which render current designs obsolete.

1) Divestiture of channels 52-69. Current long-range Yagi antennas (the ones which look like a giant arrow) are designed to give good reception across low-band VHF channels 2-6, slightly higher-band VHF channels 7-13, and UHF channels 14-69. Besides picking up the channels you want, such antennas unavoidably pick up electrical "noise" which interferes with reception (snow and audio static on NTSC, video and audio dropouts on ATSC). Newer antennas will only need to receive channels 2-51. By modifying the reception bandwidth to reject signals in the 52-69 range, reception quality on the remaining channels will be improved.

2) ATSC channels will be moving. This affects your antenna choice. Right now most broadcasters have been given a UHF channel to use for ATSC along with their current NTSC channel which could be VHF or UHF. Next February, when NTSC is shut down, the broadcasters will move their ATSC broadcast to another channel, usually their former NTSC channel. This affects your antenna choice. If all your channels will be UHF after the February move, you can select a UHF-only antenna. If you have a mix, you will need an antenna which receives both--and unfortunately adds VHF noise to the UHF channels and UHF noise to the VHF channels.

I've seen very little discussion on these points--one technical paper on the first one and nothing on the second. In fact I had to search for quite a while to figure out what would happen with channel assignments after the cutoff.

Larry M
eliwhitney
Major Contributor
Major Contributor
Posts: 484
Joined: Thu Dec 07, 2006 5:14 am
Location: Oklahoma

New Antennas

Post by eliwhitney »

Hi lmarks -

Perhaps a "mapping" of the new powered Smart Antenna from the recently-announced
RCA lineup may be done soon ?

Even @ $99, it might be very helpful to many still trying to 'cope' with O.T.A.

eli
lmarks
Member
Member
Posts: 25
Joined: Wed Dec 07, 2005 11:06 am

I don't have good ATSC success with indoor antennas

Post by lmarks »

Eli, my situation is that the antenna farm is about 20 miles to the southeast, but directly across the street from me, on the signal path, is a granite ridge about a story or two higher than my house. 10 blocks away is an 11-story retirement home. If I use an indoor antenna, I must tweak it so I get what little signal spills over the ridge and don't get the multipath interference from the tall building. I have much better success with a directional Yagi on a short mast on the roof.

My Yagi was destroyed in high winds in February, and I've been thinking about getting a new one, but I'd like to get one that cuts off at channel 51 and so far no one seems to be offering one. If you find something (with a long beam, say 110"), let me know.

Larry M
akirby
Major Contributor
Major Contributor
Posts: 819
Joined: Mon Jul 09, 2007 2:52 pm

Post by akirby »

I've posted the FCC's final channel assignments several times - do a search. I don't have the link on this pc.

What will your final channels be?

Do you really think that removing the high UHF channels will make a noticeable improvement in antenna performance?

And it's not necessarily accurate to say that most stations are changing their ATSC channels. I'll have to check the table again but from what I remember a large portion of the stations were sticking with their current ATSC channels, probably for exactly that reason.
lmarks
Member
Member
Posts: 25
Joined: Wed Dec 07, 2005 11:06 am

All are UHF except WTVD

Post by lmarks »

WTVD is the one channel that moves to VHF. All the others are UHF. Otherwise it would be a simple decision to get a UHF-only antenna (ideally, 14-51, not 14-69 or 14-83).

WTVD is the ABC affiliate, and there's not another one within reach. I suppose I could put a high-band VHF antenna pointed directly at WTVD and a UHF antenna on the rotator. I already have two downleads and a really good quality A-B switch.

Or maybe just go UHF only and sacrifice ABC.

Larry
akirby
Major Contributor
Major Contributor
Posts: 819
Joined: Mon Jul 09, 2007 2:52 pm

Post by akirby »

What VHF channel is WTVD using? I know the CM4228 UHF 8 bay bowtie will pick up down to VHF channel 10 - many of us in Atlanta are doing it right now. If it's lower than that just get a VHF Antenna cut specifically for that channel.
lmarks
Member
Member
Posts: 25
Joined: Wed Dec 07, 2005 11:06 am

WTVD is on 11

Post by lmarks »

WTVD will be broadcasting on 11. I was thinking of trying a UHF antenna to see if I could get 11. Thanks for the encouragement.


I'm wary of trying a bowtie, although I may because it's a small investment. I need to have something with a very narrow beam so I can get the main signal without the bounce (about 15 degrees off axis) from the retirement home (or alternatively, the bounce without the direct signal). My recollection is that bowties have a very broad reception pattern.

My last antenna was similar to this 160" one from Radio Shack:
http://www.radioshack.com/product/index ... age=family , their part number 15-2156, which is highly directional.

Just took a quick look and could not find comparative patterns for Yagi and bowtie. Do you have a reference?

Larry
eliwhitney
Major Contributor
Major Contributor
Posts: 484
Joined: Thu Dec 07, 2006 5:14 am
Location: Oklahoma

Various Antenna properties ....

Post by eliwhitney »

Hi lmarks -

Will this help ? -

http://www.starkelectronic.com/cmg2.htm

There's also a "multi product" plot -

eli
lmarks
Member
Member
Posts: 25
Joined: Wed Dec 07, 2005 11:06 am

Well, I was really looking for polar plots

Post by lmarks »

EW, the information I'm seeking could be extracted from the website you referenced, but I'm really looking for polar plots like the one here:
http://www.originlab.com/www/products/G ... s=8&lm=215

This sample has fairly high gain out to about 30 degrees either side of its main axis, and a pretty good front-to-back (F/B) ratio--that is low gain from the reverse side.

Other antennas may have a broader front lobe, or side lobes.

I am looking for an antenna with a fairly narrow front lobe and minimal side lobes, so I reject the multipath from the retirement high-rise. I'd like to see polar plots for Yagi and 8-bay UHF antennas. I suspect the 8-bay has a pretty broad lobe.

Larry M
Post Reply