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Fixed antenna for CICO & CBET

The technical side of broadcasting. Think IBOC is a sham? Talk about it here! How about HDTV? Post DX reports here as well.
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MWmetalhead
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Re: Fixed antenna for CICO & CBET

Post by MWmetalhead » Mon Dec 14, 2020 7:20 pm

Completely agree about the benefits of gain derived through natural antenna design.

Admittedly, I did not do a good job earlier distinguishing between "good" gain and "fake" gain.



jimh
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Re: Fixed antenna for CICO & CBET

Post by jimh » Tue Dec 15, 2020 9:14 am

Regarding reception of CICO and CBET: I recommend you look at your signal path to their co-located transmitter site. Use GOOGLE EARTH to draw a line from their antenna to your location. Carefully look along the path to see if there are any large, tall buildings that are in the path, particularly in the downtown Detroit and Windsor area. Reception of either signal will affected if your path aligns with a large structure. If your path to CICO/CBET does not transit through the downtown Detroit and Windsor area, you will probably not have difficulty receiving them.

Another useful feature for GOOGLE EARTH: you can plot the terrain profile of the path. Save the line as a "place." Then you can right-click on the place item and choose "Show Elevation Profile."

Here is an screen capture demonstrating this method:

http://continuouswave.com/radio/graphic ... xample.jpg

The terrain profile shows there is no obstructing terrain between my location and CBET/CICO. If you add the tower height at both ends of the path, you can infer the path will be reasonably clear of any terrain obstructions, other than big buildings.



CK-722
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Re: Fixed antenna for CICO & CBET

Post by CK-722 » Tue Dec 15, 2020 12:06 pm

Circular and Elliptical polarization signals lose usually the Vertical polarization component when they encounter a knife edge terrain obstruction and change handedness on reflection.. While light is incoherent and randomly polarized and radio waves are coherent and polarized, in most other ways they are very similar. Consider polarized sunglasses, which are oriented to cut down reflections off horizontal surfaces like a car hood , which often create glare. Once you go through the reflection, the light is plane polarized while still incoherent.

So unless the signal is LOS, you probably wouldn't gain much gain form a circularly or elliptically polarized antenna,.


Is THAT where they got the idea for the 486-SX?

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innate-in-you
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Re: Fixed antenna for CICO & CBET

Post by innate-in-you » Tue Dec 15, 2020 11:44 pm

n8fnr wrote:
Fri Dec 11, 2020 2:07 pm
I want to put up a fixed TV antenna at about 20 feet for CICO and CBET in Windsor. According to RabbitEars they are 27 miles from my house. Since CBET is high VHF (channel 9 actual channel) and CICO is channel 19 I will need a VHF/UHF antenna. I am trying to get a smaller antenna and wonder if the folks here think that this will be good enough for my needs; https://www.solidsignal.com/rca-high-vh ... nna-ant751. Sadly there is no gain mentioned. Or perhaps I need one that is a little bigger? Any suggestions?

Thanks
Zack S
Winegard has VHF-high/UHF combination antennas in a few sizes.

They also have a UHF/VHF-high antenna (HD-7000R) with a very short boom which includes a VHF-Low addition that converts it into a triband antenna.

However, it is not OTARD compliant with the VHF-Low kit installed.

Without installing the VHF-low kit, it fits inside a one-meter sphere, making it compliant with the OTARD rule.

It will not fit in a 1m sphere with the VHF-Low kit.

With the VHF-Low kit, it is bi-directional, with a significant back lobe (it just so happens, in my case, that the back lobe is in the direction of the only VHF-low station, whilst the other stations are in the front lobe.



CK-722
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Re: Fixed antenna for CICO & CBET

Post by CK-722 » Wed Dec 16, 2020 1:12 am

HD7000R

Image

I called Winegard a couple of months ago and asked the technical department if they had any new designs. They said no.


Is THAT where they got the idea for the 486-SX?

Same (x, y, z), different (t)

Your bullet missed my trial balloon.

RTN Price. Not guaranteed. As of 12:30, 157.71 Down 0.22.

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jimh
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Re: Fixed antenna for CICO & CBET

Post by jimh » Wed Dec 16, 2020 9:05 am

An antenna for CBET-9 or CICO-32 does not need VHF low-band elements.



jimh
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Re: Fixed antenna for CICO & CBET

Post by jimh » Wed Dec 16, 2020 9:16 am

CK-722 wrote:
Wed Dec 16, 2020 1:12 am
I called Winegard a couple of months ago and asked the technical department if they had any new designs. They said no.
On the new topic of revised antenna designs:

With the repack, the UHF TV antenna could be optimized for the narrower band. With only Channels 14 to 38, a new antenna could be designed for just 470 to 608-MHz.

Legacy UHF TV antennas were designed for Channels 14 to 83, 470 to 890-MHz.



CK-722
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Re: Fixed antenna for CICO & CBET

Post by CK-722 » Wed Dec 16, 2020 9:40 am

jimh wrote:
Wed Dec 16, 2020 9:16 am
CK-722 wrote:
Wed Dec 16, 2020 1:12 am
I called Winegard a couple of months ago and asked the technical department if they had any new designs. They said no.
On the new topic of revised antenna designs:

With the repack, the UHF TV antenna could be optimized for the narrower band. With only Channels 14 to 38, a new antenna could be designed for just 470 to 608-MHz.

Legacy UHF TV antennas were designed for Channels 14 to 83, 470 to 890-MHz.
I pointedly asked about an antenna optimized for 14-36 as well as an add on VHF-Low element. She said no. Could they just be trying to do that before someone else, and didn't want to reveal it?


Is THAT where they got the idea for the 486-SX?

Same (x, y, z), different (t)

Your bullet missed my trial balloon.

RTN Price. Not guaranteed. As of 12:30, 157.71 Down 0.22.

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km1125
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Re: Fixed antenna for CICO & CBET

Post by km1125 » Wed Dec 16, 2020 12:46 pm

jimh wrote:
Wed Dec 16, 2020 9:16 am
CK-722 wrote:
Wed Dec 16, 2020 1:12 am
I called Winegard a couple of months ago and asked the technical department if they had any new designs. They said no.
On the new topic of revised antenna designs:

With the repack, the UHF TV antenna could be optimized for the narrower band. With only Channels 14 to 38, a new antenna could be designed for just 470 to 608-MHz.

Legacy UHF TV antennas were designed for Channels 14 to 83, 470 to 890-MHz.
Don't know why they don't have redesigns in the works, or out already. You'd think they'd have improved performance if they didn't have to stretch the bandwidth all the way to 890. It also would drop the 'gain' in the whole LTE band, which I understand is a problem for some folks as it overdrives amps or TVs.

I posted in another thread about the Hoverman antenna, which was patented in 1952 but did poorly commercially because it couldn't cover the upper half of the UHF band. It was nearly perfectly designed for the present-day UHF TV broadcast spectrum. Just came out 65 years too early!



CK-722
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Re: Fixed antenna for CICO & CBET

Post by CK-722 » Wed Dec 16, 2020 1:23 pm

What are the devices in the center of each side of the Low VHF dipole? Center loading? Capacitance coupling? Explain if you can what that does in this case.


Is THAT where they got the idea for the 486-SX?

Same (x, y, z), different (t)

Your bullet missed my trial balloon.

RTN Price. Not guaranteed. As of 12:30, 157.71 Down 0.22.

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jimh
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Re: Fixed antenna for CICO & CBET

Post by jimh » Wed Dec 16, 2020 3:54 pm

innate-in-you wrote:
Tue Dec 15, 2020 11:44 pm
...HD-7000R...which includes a VHF-Low addition....is not OTARD compliant with the VHF-Low kit installed...Without installing the VHF-low kit, it fits inside a one-meter sphere, making it compliant with the OTARD rule...It will not fit in a 1m sphere with the VHF-Low kit.
I don't see where you came up with the criterion that an off-air TV antenna designed to receive local signals must fit into a one-meter sphere in order to be qualified for protection under the Over-the-Air-Reception Devices (OTARD) regulation. The FCC says:
The following antennas or dishes are covered by these rules:...An antenna that is designed to receive local television broadcast signals.
Source: https://www.fcc.gov/media/over-air-rece ... vices-rule

The official rule is found at:
https://www.law.cornell.edu/cfr/text/47/1.4000

The one-meter dimension is therein mentioned twice, but in each case in sections related to other types of services. For antennas that are "designed to receive local television broadcast signals" there is no associated sub-paragraph that imposes a limit on diameter or diagonal dimension of the antenna. The word "sphere" appears nowhere in the regulation.

Please cite your source for your notion that an antenna that receives local television broadcast signals must fit inside a one-meter sphere in order to be protected by the FCC OTARD regulations.



jimh
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Re: Fixed antenna for CICO & CBET

Post by jimh » Wed Dec 16, 2020 3:56 pm

CK-722 wrote:
Wed Dec 16, 2020 1:23 pm
What are the devices in the center of each side of the Low VHF dipole? Center loading? Capacitance coupling? Explain if you can what that does in this case.
Which of the antenna suggested to the OP to receive CICO or CBET are you talking about?



CK-722
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Re: Fixed antenna for CICO & CBET

Post by CK-722 » Wed Dec 16, 2020 4:45 pm

jimh wrote:
Wed Dec 16, 2020 3:56 pm
CK-722 wrote:
Wed Dec 16, 2020 1:23 pm
What are the devices in the center of each side of the Low VHF dipole? Center loading? Capacitance coupling? Explain if you can what that does in this case.
Which of the antenna suggested to the OP to receive CICO or CBET are you talking about?
I'm sorry. I mean the HD-7000R, pictured in my previous post. If the thing in the middle is inductive, it would make the element function as a 7-13 element for higher frequencies, 2-6 for lower frequencies, as 2 PI fL would be a greater reactance at higher frequencies.

Image


Is THAT where they got the idea for the 486-SX?

Same (x, y, z), different (t)

Your bullet missed my trial balloon.

RTN Price. Not guaranteed. As of 12:30, 157.71 Down 0.22.

Artificial Intelligence is a Child that needs a Parent to guide it through.

jimh
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Joined: Thu Sep 22, 2011 12:02 am

Re: Fixed antenna for CICO & CBET

Post by jimh » Thu Dec 17, 2020 1:19 pm

CK-722 wrote:
Wed Dec 16, 2020 4:45 pm
...I mean the HD-7000R.... If the thing in the middle is...
The image is really very low resolution. I don't understand what "the middle" refers to. It looks to me like one or two elements are lengthened and there is a joint of some kind. I cannot offer any inference about what that joint is.

This topic seems to me to be extremely tangential to the discussion because neither CBET or CICO would need a low-VHF element, and the OP requested advice on antennas of limited size. So increasing the element size of the antenna recommended to add low-VHF would not be particularly useful for receiving CICO or CBET.



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Ben Zonia
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Re: Fixed antenna for CICO & CBET

Post by Ben Zonia » Thu Dec 17, 2020 2:36 pm

If you don't like subjects going off on tangents, you may be on the wrong board. Often, the tangents are more interesting than the original topics.


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