Does Ham Radio Antenna Polarization Really Matter? (6 Meters VHF)
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- เผยแพร่เมื่อ 4 เม.ย. 2024
- Let's see if Ham Radio Antenna Polarity makes a difference on 6 meters
► DISCLAIMER
This video is for entertainment purposes only. I am not an expert on this subject and what I'm showing here are just observations.
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#hamradio #antenna #vhf - วิทยาศาสตร์และเทคโนโลยี
That was interesting. My father had a 40 foot tower next to our house growing up and used a horizontally polarized beam for use on 2 meters. He frowned on using repeaters and liked to run direct. On higher power, he could easily get Pa. and Long island as well as Southwestern Ct. It was on a antenna rotor as well. He used it for "Civil Air Patrol" frequency 148.15Mhz.
Neat video! KC2RDU Bob
Wouldn't the mast have interfered with the drivin element, I see companies make stand offs 1' to 18" that go horizontal between the mast and beam so the antenna is away from the steel mast because it will act as another element but at the wrong length and distance from the drivin, Good video.
The mast I used was fiberglass so it shouldn't affect the antenna. However, as I explained in the video, the coax may have interacted with the driven element a bit.
The coax does not only affect the SWR, but it also affects it radiation pattern.
From horizontal to vertical our visa versa is around 25dB, as far as I know. But you have to remember that polarization can switch depending on the path the signal is traveling. Reflection can chance polarization. That's why on HF with signals bouncing of tthe ionosphere (wich is reflection) you can use horizontal and vertical without noticing much different. Signals will probably be circular, because the mirror chances form.
But on VHF and UHF signals do not reflect but they will refract (tropo) . And that does not chance polarization. So yes on VHF and UHF polarization does matter and it matters a lot. That is why I prefer circular polarization for my antennas. Circular polarization to either vertical our horizontal is about 3dB loss.
BTW sporadic E reflection goes into the same category as bouncing to the ionosphere, so on 6m when signals are reflected to the E layer polarity os not so big of a game changer....
So it depends rather your signal is ground wave refracted our reflected...
Man, as a former resident of this neck of the woods, I miss having the use of both ends of the 6m band. One possible influence here is that horizontal polarization seems to be able to deal with terrain...the nooks and crannies...the hills and dales...that New England is full of. There's also the possibility that some repeaters may not always use purely vertical antennas. Definitely smiling watching you get into all those machines though. Used to run a Hy Gain VR-6 vertical at home.
Good point on terrain being a factor!
Interesting video. I have never played with 6m. That is a summer project that I plan to do. I have a ham stick dipole setup as well as an Opek HVT400B mobile vertical capable of 6m.
Great test! I wonder if your vertical SWR would be better with the gamma above the boom.
I'll have to give that a try
Thinking the same thing. Worth a try anyway, gamma on the high side
Thanks for an interesting experiment!
You are welcome!
Anybody can sit at their computer with their modeling software and tell us something won't work but it's more important and educational to perform the tests.
Rob, I'm curious if you tried with the gamma match on top of the driven element when vertical?
I didn't. I wouldn't think that would make a difference but it's worth another test to see
Cool video. I'm wondering where the repeaters are in relation to the antenna. wondering if that has anything to do with the signal strength. I would think it does.
The radiation pattern of the antenna is definitely a factor.
Another great video. Reminds me I have not tried 6m yet. Would like to fabricate one from arrow shaft material for portable work.
6m is a fun band, I think you'll enjoy it once you try it
Good real life experiment.
Polarization really only matters on groundwave, and most people are not close enough to a 6m repeater to use groundwave. Once you bounce your signal off of the ionosphere your polarization will be twisted into a random orientation due to Faraday rotation. On VHF groundwave isn't much farther than line of sight. Of course for vertical polarization to be better on groundwave, the repeater would need to be using vertical polarization as well. For skywave your takeoff angle also matters which will be influenced by the height of your antenna.
we have ton of local activity on 6 meter - FM,AM,SSB,CW,FT8 are all active here on ground wave
Very interesting results. Is it possible you could do one more test with the elements at 45 degrees. I was told by a Ham years ago that you then get the best of both worlds. Would be very interesting to know if it works better. Forgot all about it until I saw your video. Keep up the good work.
I'll have to give that a try
still working out my difficulties with 6m but, your experiment runs parallel with what I have seen...gets worse the higher you go, at least with me
Interesting
You may have had the radiating element facing the ground instead of facing up when in vertical?
I don't think that would really matter but it's worth trying another test to see. Both elements radiate but having the gamma match close to the coax may account for some of the swr increase
@@SevenFortyOne A good test either way. We've been told that vertical = FM & horizontal = SSB but my local group TX on 144.310 vertical SSB as not all of us have beams. I'm running a net here in Scotland in June vertical SSB just so the stations who don't have a beam can join.
6m season coming up soon , june
Thanks for reminding me 👍
Very Interesting test....Each S unit = 6 dBm signal strength Difference....Theoretical 90° antenna Mismatch loss >30 dB.....Next, Try your Yagi beam antenna at 45° polarity Angle to Dynamically test for Theoretical 3 dBm polarity Mismatch loss...Best predicted Comprise signal loss beam polarity should be 45° .Your observed Vswr Detuning effect most Likely due to the Metallic mast close Proximity to Vertical radiator Driven element
The mast was fiberglass
not a question
very old question answered long ago
this video is useless
So is this comment 👍
I don't know why this guy always has to be such an ass. He has some very knowledgeable videos but his interaction with people leaves a lot to be desired.
Were you aiming the antenna at each repeater? Or just leaving it pointed at the oak tree?
I left it pointed at the tree for the entire test