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Discussion Starter · #1 ·
Hi
I hope you can help me I have some questions.
Building Rectangle Plant Font House

Can you explain why this antenna model that I put on my balcony (30 feet from ground) has the main element, (the folded dipole), lying down instead of up, like any other antenna? advantages/disadvantages See the attachments.
I want to get better reception of some FM stations in Montreal, but I have a limited space on my balcony.
I live in Quebec City

Does a 4 elements FM antenna like the Stellar Labs Model #30-2460:https://www.farnell.com/datasheets/...78.254980428.1634345285-1948104228.1633359304
would be better, or there is not enough difference to make a change?

Thanks a lot!

Yvan Carette
 

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The stellar labs has two director elements, instead of just one, it will likely have a bit more gain, and
a bit more directivity than the one in your photo.
For your other question, a dipole's radiation pattern is in the shape of a donut, so it doesn't matter.
scroll down to radiation pattern and gain. That's a Vertical dipole example.

 

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I want to get better reception of some FM stations in Montreal, but I have a limited space on my balcony.
I live in Quebec City
That's quite a hike, even for FM. 145mi (233km) is beyond the range for FM or TV signals under most circumstances. The best I've seen for reliable reception is about 100mi-120mi and that was with more powerful stations than is allowed today. I'd suggest using the internet to stream the stations as most now provide free internet streaming.
 

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Discussion Starter · #6 ·
Very amazingly, on clear mornings and evenings, with this southwest facing antenna, I can receive about 6 stations from Montreal, a few from Sherbrooke and even VPR from Mount Mansfield in Vermont at 107.9.
I live in the St-Lawrence valley and I think this flat terrain helps. Signal levels is variable between 2 and 5 on a scale of 10, on an old FT-11 FM analog tuner from Magnum Dynalab.:)
 

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I've seen stations from that far away come in regularly as well. Clear mornings and evenings in warm weather are conducive to tropo. It also helps if the stations are clear channel with no other stations on the same frequencies. I doubt that a 4 element instead of a 3 element antenna will make much difference. A much longer, more directive antenna might tune out interfering stations and increase the signal strength a little but that doesn't appear to be the issue. The St. Laurence valley may be doing some good by blocking other stations on the same frequencies from interfering. The cable company here had antennas on a 500' tower which allowed for consistent FM reception at 100 miles. I did the same for awhile when I lived on higher ground. FM typically does quite well with lower signal strengths as long as there is no interference from other stations.
 

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Discussion Starter · #9 ·
OK thanks for the cue. Already 7 or 8 years ago, my cable TV company stopped offering analog FM sets to allocate the bandwidth to digital channels....always quantity at the expense of quality. Monumental mistake in my opinion because the quality of digital reception in streaming on average at 128 kbps or lower does not have the sound quality of a stereo FM signal received on an ANALOGUE quality tuner that very few companies produce now. For me, quality over quantity...in many things in our lives!
 

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Can you explain why this antenna model that I put on my balcony (30 feet from ground) has the main element, (the folded dipole), lying down instead of up, like any other antenna? advantages/disadvantages See the attachments.
That type of Yagi is called a loop fed array or a low-noise array. The horizontal loop is also called a coplanar loop.

The advantages are that it has a very clean pattern that picks up less interference from the sides and the rear. It also allows direct feed with coax so that a balun isn't needed. The loop fed array is becoming more popular with hams that like to work DX.
 

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I personnally believe that 128 kbps sounds better than analog FM, but you need good quality equipment. I use a Cambridge Audio CXN v2 streamer. The sound quality is amazing and I can access thousands of stations. Moreover, some stations transmit at 256 or 320 kbps. They sound just like a CD.
 

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I agree. The FM signal must be pristine to sound better than a good digital stream. Even then, analog FM is intentionally rolled off at around 15KHz, less if digital co-channels are present, and is often compressed. The digital co-channels are typically inferior to a good digital stream as well. I prefer FLAC or similar lossless encoding which preserves the quality of CD sourced music streams. Few broadcasters offer lossless formats but, when available, they are superior to any standard MP3 format and FM. So called master quality streams are available on some music services, which is close to DVD Audio quality and is vastly superior to CD and FM. Please excuse me while I start some master quality tunes on Tidal. ;)
 

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lying down instead of up, like any other antenna? advantages/disadvantages
Main difference is matching technique.
Classical folded dipole has 200-300 Ohm impedance and typically matched to coax cable via 4:1 Guanella current balun, or Lambda/2 coax loop.

When folded dipole is lying down in Uda-Yagi design, it's operation principle is quite different.
In classical dipole, both parts (upper and bottom) have identical coupling to reflector and to director.

In "Loop-fed array yagi" one part has more coupling with reflector and other part more coupling with director.
Typically, spacing is adjustet to get 50 or 75 Ohm and use 1:1 balun instead of 4:1 balun
 

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Typically, spacing is adjustet to get 50 or 75 Ohm and use 1:1 balun instead of 4:1 balun
Yurii is correct. You no longer need a 4:1 balun, but you do need a 1:1 balun. This is because when you go from balanced antenna feed point to unbalanced coax feedline, there will be current on the outside of the coax without a 1:1 balun. This current will distort the antenna pattern.

The antenna will still function without the 1:1 balun, but the pattern will not be clean.
 

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Discussion Starter · #16 ·
Oh... the box where I connected the 75 ohm cable is already ready for the 75 ohm. According to the manufacturer's instructions I just had to screw the cable in. I don't want to broadcast but only receive FM stations. Probably the balun is inside the black box, if not, what is the part to add that would be a 1: 1 balun with coaxial female F input and output. I haven't seen anything like that on the internet...
 

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Oh... the box where I connected the 75 ohm cable is already ready for the 75 ohm. According to the manufacturer's instructions I just had to screw the cable in. I don't want to broadcast but only receive FM stations. Probably the balun is inside the black box, if not, what is the part to add that would be a 1: 1 balun with coaxial female F input and output. I haven't seen anything like that on the internet...
It's probably OK as it is for your application on your balcony. Yurii was talking about the ultimate purist applications.
 
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