Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [polarization]

25 questions
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votes
8 answers

Should I chose a vertical or a horizontal HF antenna?

If I only have the budget for one HF antenna, should I chose a vertical or a horizontal antenna?
Timtech
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Why can I receive a vertically polarized signal on a horizontally polarized antenna on HF and vice versa?

One explanation I found is that a signal reflected from ionosphere is always circularly polarized. Thus it can be received by both vertically and horizontally polarized antennas (naturally, with 3 dB attenuation). However I don't trust the source…
Aleksander Alekseev - R2AUK
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5
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1 answer

What is the difference between "Cross Polarized" vs "Circularly Polarized" Antennas?

What is the difference between cross-polarized yagi antennas and circularly polarized antennas?
metropolis
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5
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3 answers

Which way is a yagi polarized?

I am installing a yagi antenna that will receive signals from multiple omni antennas that are vertically polarized. Which way should the elements of the yagi point to match? Up and down, or horizontal? I must not be asking the question correctly to…
T3chie - Bitoku Labs
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Receiving the ISS SSTV: dipole antenna configuration and orientation

In short I am trying to receive SSTV Images from the ISS (145.8Mhz) and I all have is a simple "bunny ears" dipole antenna. In what configuration (straight, vee shaped, upside down vee, ...) and orientation should I place the antenna to optimize…
Steven
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4
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2 answers

Does antenna width/shape affect resonant frequency like length does?

I was wondering if I made an antenna from a Rohn 25G tower, would it have the same resonant frequency as a pole of the same height (assuming guys are insulated)? Also with the Rohn antenna, the waves would be both vertically and horizontally…
Synaps3
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2 answers

Why do horizontally-polarized RF waves reflect better off ground than vertically-polarized waves?

It's a well-known fact among hams who use HF frequencies that horizontally-polarized RF waves reflect better off of ground than vertically-polarized waves. This explains why ground conductivity is so important to the performance of a vertical…
rclocher3
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3
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2 Meter horizontal or vertical dipole polarization?

When should I use one polarization over the other on 2 meters? I've looked at the radiation patterns for horizontal dipole and seen how it changes based on mounting height. I haven't been able to find any information on how the vertical dipole…
KM4NTK
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3
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Rhombic Polarization Question, provided radiation maps

I am trying to engineer my first antenna to get on the air. I need to hit a repeater 50 miles away at a lower elevation than me so that I can use its IRLP nodes. Would this mean I am looking for low angle radiation? 25 feet up with an HT in the…
Zeke Legge
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3
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2 answers

Dual Polarization Yagi Antenna for 10 m

Imagine that someone has built a 4 element horizontal yagi antenna for 28 MHz with elements insulated from the boom, and with the driven element not split in the middle and using a gamma match to set the feed point impedance to 50 ohms. Then,…
Andrew
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3
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Are circular polarized antennas on HF subject to polarization fading?

Consider the common scenario of two amateur radio operators communicating through an ionospheric channel. Typically, each station will have a linearly polarized antenna, like a dipole or a vertical. I understand that the ionosphere will randomize…
Phil Frost - W8II
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Circular polarized antenna feed changes as I rotate it?

I had a 100cm prime focus dish laying around and I thought of making a circularly polarized feed for it, since it seemed pretty straightforward from what I've been reading. Helical feeds are supposed to be very wide and forgiving. So I built this…
hjf
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Antenna polarization when dealing with satellite communications

It's easy to understand, conceptually anyway, the difference between a horizontally polarized antenna and a vertically polarized one, when referenced to ground. However, when they are pointed nearly straight up at a satellite that reference is…
mike65535
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Horizontal dipole radiation gaps

Consider the radiation pattern of a horizontal dipole mounted at a height of 1.75λ. Is it possible for a receiving station's antenna to be mounted at a certain height such that the radiation of the transmitting station misses the receiving antenna…
KM4NTK
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Would two perpendicular dipoles work to avoid polarization mismatch?

What would happen if you made an antenna consisting of two perpendicular dipoles tuned for the same frequency and connected to the same feed line? Would this work to avoid polarization mismatch loss?
kj7rrv
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