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-   Antenna Research & Development (http://www.digitalhome.ca/forum/186-antenna-research-development/)
-   -   A rather unusual tv antenna (http://www.digitalhome.ca/forum/186-antenna-research-development/276281-rather-unusual-tv-antenna.html)

Groundedforlife 2017-08-08 08:24 PM

This popped up in another discussion and I am a little more than curious about the design. Your thoughts are appreciated.
https://drive.google.com/file/d/0B_6...w?usp=drivesdk

Groundedforlife 2017-08-08 08:37 PM

This is the addy. http://maxrangetv.com
Very different.

Jorgek 2017-08-09 12:37 PM

Interesting. However it always makes me suspect when a company uses a lot of adjectives to describe their product rather than actual performance numbers.

Groundedforlife 2017-08-09 04:15 PM

They say it can be used for tv and it must pick up radio, I've never seen anything like it. Actually I like the way the reflector is built.

holl_ands 2017-08-10 05:30 PM

The Active Element is a "Bi-Conical" type, frequently used for very wideband, calibrated EMI/EMC Measurements.
It's basically a VERY FAT and hence WIDEBAND DIPOLE, but Gain won't be any higher than about 2.2 dBi.....with Excellent SWR:
3109 Biconical Antenna Charts | ETS-Lindgren

So about the most Gain it could hope to provide with [ONLY FOUR!!!] Reflector Rods is MAYBE 5.5 dBi.....however, SWR performance "should" be fairly Wideband, probably AT LEAST Ch7-51 + FM [Ch2-4 MIGHT exhibit high SWR], although the use of only ONE Size Reflector Rods will compromise either UHF and/or VHF Performance (I COULD model/optimize it to find out).

Even a simple Bowtie has more Gain in UHF Band:
UHF Bowties - NO Reflector
6-Whisker Bowtie UHF Raw Gain = 3.4 - 5.0 dBi and SWR (300-ohms) under 2.4
and Hi-VHF Raw Gain = 1.8-2.9 dBi, but SWR is Excessive.

Which means even a simple 2-Bay Bowtie with Reflector will run circles around it in the UHF Band....where most people need even HIGHER Gain:
UHF 2-Bay Bowties with Reflector - ImageEvent

Jorgek 2017-08-10 06:29 PM

Is it a wonder that the vendor/manufacturer does not post any specifications.

Jase88 2017-08-11 09:54 AM

I like that it uses solid rods rather than tubes and is made in the US. Price is high. Based on holl_ands evaluation of the design, I'd stick with something else, like a reputable 4 bay.

Either way, they're currently not shipping due to their facility moving.

Groundedforlife 2017-08-11 04:05 PM

Thank you holl_ands and everyone for explaining that. I also wondered why the builders site was so vague. These days there are many oddball antennas that claim to perform miracles it mind numbing, I'll stick with my ugly old bowtie!

majortom 2017-08-12 07:21 AM

IMO, solid rods aren't doing anything for ya in an antenna but adding to the mechanical
loading, making it heavier than it needs to be.
RF current is travelling on the outside of the conductor, Skin effect remember.
It may be that they used solid conductor due to how it is assembled??
Doubt that it would have anything to do with the rf design though.

Groundedforlife 2017-08-12 07:24 PM

Good point majortom, the rod does add weight. Looking at the way the elements are bent, solid rod is the only practical solution for ease of manufacturing. Expensive solution. They no doubt used the rod in the reflector for strength and the fact that they had plenty of material. It also seems that the ends have a cast hub and possibly the center piece, also heavy and expensive.

holl_ands 2017-08-13 06:23 AM

Perhaps they got a good deal on RFI/EMI Test Antennas [perhaps a Going-Out-Of-Business Sale???].....which of course begs the question as to how well they work in UHF Band.....MOST STANDARD TEST Antnnas are designed to max out at 300 MHz (which I'll bet is tied to some specific MIL-SPEC and/or FCC Test Requirements)....

YUP: EMI/EMC Test Antennas come in the fol. "STANDARD" ranges, per MIL-STD-461, EMC Test Requirements:

"Depending on the operating frequency range of the EUT, the start frequency of the test is as follows:
EUT Operating Frequency Range, Start Frequency of Test
10 kHz to 3 MHz, start at 10 kHz
3 MHz to 300 MHz, start at 100 kHz
300 MHz to 3 GHz, start at 1 MHz
3 GHz to 40 GHz, start at 10 MHz"

majortom 2017-08-13 10:28 AM

yeah, maybe they frequency scaled the standard design for the VHF/UHF band?
I shouldn't criticize what someone else has done, when I know that I could do no better.
I wonder what it would do if you installed it for vertical polarization, so the nulls are facing up and down, instead of to the horizon? Would it's doughnut behave like an omni?
Might be all some people need, a sturdy outdoor antenna, if they are in a urban environment near strong signals bouncing around all over?

ProjectSHO89 2017-08-13 02:16 PM

If you did that, it would be vertically polarized for reception and their would be a substantial penalty for cross-polarization reception in the majority of cases as the default polarization in North America is horizontal (optionally, stations can add vertical polarization to their signals).

Jase88 2017-08-14 10:54 AM

Quote:

Originally Posted by majortom (Post 2946193)
IMO, solid rods aren't doing anything for ya in an antenna but adding to the mechanical
loading, making it heavier than it needs to be.

I was thinking of the occasional ice storm that we get in this part of the world, and not RF performance. Agreed that it's a toss up with respect to the additional weight.

Danster 2017-08-14 02:26 PM

Quote:

Originally Posted by holl_ands (Post 2946673)
Perhaps they got a good deal on RFI/EMI Test Antennas [perhaps a Going-Out-Of-Business Sale???].....which of course begs the question as to how well they work in UHF Band.....MOST STANDARD TEST Antnnas are designed to max out at 300 MHz (which I'll bet is tied to some specific MIL-SPEC and/or FCC Test Requirements)....

YUP: EMI/EMC Test Antennas come in the fol. "STANDARD" ranges, per MIL-STD-461, EMC Test Requirements:

"Depending on the operating frequency range of the EUT, the start frequency of the test is as follows:
EUT Operating Frequency Range, Start Frequency of Test
10 kHz to 3 MHz, start at 10 kHz
3 MHz to 300 MHz, start at 100 kHz
300 MHz to 3 GHz, start at 1 MHz
3 GHz to 40 GHz, start at 10 MHz"

I have nothing to bring to the conversation, just coming here to state something I always like to see here in the forums.

I know a few things about how to setup TV antenna (as far as plugging goes) but once in a while, I like the source of info you bring. Just about every posts you have ever written, it is always either to set the record straight or help someone. This is the type of people that bring other valuable info to other members.

Kudos to you sir and thanks for sharing your knowledge. ;)


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