Ham Radio: SLOPER ANTENNA - POSITIVES & NEGATIVES
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- Опубликовано: 28 авг 2024
- Lots of folks you are into portable work, POTA, SOTA use end fed half waves, with 40 metres a very popular band. Often, these are deployed as a sloper. What are the pros and cons of these?
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From Colorado, using an EFHW sloper fed a few feet off the ground, with a 25 ft. mast on the high end, I'm able to get to Europe, Mexico, Canada, and South America with 80 watts.
Great video Tim, spot on with what I've experienced with my sloping backyard antennas in Poland and the very reason I experimented with the L shape. I was trying to lower my takeoff angle with an EFHW. As you know I love your antenna modelling and theory videos. keep them coming my friend!!
Thanks Walt! Its all good fun. Happy new year sir!
Endfed LW is pretty much the only antena I use so this video is beyond interessting for me. Thnx !
Thank you!
I liked this one, I typically run a 20m long efhw in an Inv portable. Thanks Tim.
Cheers Callum and happy new year to all there
Thas *is* interesting Tim. My end fed at home is a sloper, facing south, just because that's the only way it fits! It is relatively flat though.
I wonder if you ever model antennas against different ground types? There is a theory that we get away with low masts on rocky mountain tops because the real RF ground can be several metres below the surface layer of shattered rock.
All the Best for 2023.
73, Fraser MM0EFI
That sounds a very interesting avenue to investigate Fraser 73
Great video Tim, nice sound quality. 😊
Cheers Mike! Hope you have a healthy and happy 2023
Great Tim! Your videos are a treasure.
That's very kind! 73
Good stuff! Happy New Year.. 73 Leo.
And to you Leo happy new year 73
Very interesting Tim - being a PoTA guy running QRP I've had a end-fed 40m antenna in my collection for a while, the trouble is that the magloop is so easy to setup ! I have a PoTA activation planned for 2/1/23, will see how the weather is and if I can get the 40m end fed up in the New Forest :)
Good luck Al and happy new year
Nice video Tim ... I live on a 7th floor and my antenna is a steel wire with 21 +/- meters of 0.8mm ... take off angle is about 65º above ground 3.5 meters
I work 80, 40, 20, 15 and 10 meters with very good reports
Happy Near Year - CR7BDO / 73
Sounds a great antenna Jose. 73
Was interesting Tim, thanks for that,..cheers n happy new year!
Thanks Tom and to yourself!
I have an end fed random wire that I use at my home in a portable configuration. That’s to say I zip tie the insulator to the top of a DX commander 10 meter pole and slope downwards… not exactly sure of the angle, but the top is facing hue south, and I was able to get into Europe (uk, Northern Ireland, Italy, Belgium, and even into Southern Africa ) with 100 watts from the east coast of the US…. One thing I can’t do for some reason is get into the west coast of the US so far. Internal ATU in my FT450D tunes all bands 80 thru 6
Sounds like a good solution!
@@timg5tm941it works! Works even better on digital modes like ft8 etc.
Great info. Thank you
Thanks!!
Well done Tim. Interesting video. I never use my endfed as a sloper, always as an inverted V. Best 73 and Happy New Year de ON4MGY Nic
Happy new year! And thanks for stopping by 73
Great Video Tim. Big improvement in the audio quality too!👍
Thanks mate!
Thanks Tim!
Thank you!
Great video Tim! Should really look into MMANA to get a feeling which way of zigzag-ing my EFHW down and into the small garden might work best.
It’s a bit addictive once you start!
right thats the experiment of the day sorted for next beach day. Ill try feed point at waters edge and walk back up with the pole.
Let me know how you get on!
is it possible to slope the ground as well...? my efhw follows a sloped ground almost in the same angle.
I’m setting up a stealth antenna at my QTH and this video was incredibly helpful. Showed that in my situation, I need to attach the high end of the sloper lower than I initially thought so that I would have a more omnidirectional antenna. That said, would there be a substantial difference in radiation pattern if the antenna feedpoint was mounted say 3m off the deck?
Likely a little more gain but not a massive increase
Did i miss something? What about if its fed from the top? Is it all the same? Thank you for the video!
Not tried this on the air but did try it when doing my initial EFHW field tests. What was profound was the SWR of the harmonics did not tie in like they did if it was an Inv L or an inv V. It was way off compared for some reason and unusable on some higher bands.
That’s really interesting Colin. I’m sure some Efhw manufacturers recommend a sloper. But there again it depends on how forgiving (lossy) their transformer design is. I suspect your 56:1 design, with greater efficiency on 10/15 is less forgiving. That’s not a bad thing as we both know. 73
@@timg5tm941 Think so Tim. Witnessed on bothy core's. The 2 common ones are very forgiving.
Interesting stuff Tim. What happens if you feed the sloper at the high end? I have seen this discussed and some antenna manufacturers recommend having the transformer elevated with the wire sloping towards the ground. 73 de Will, M0LGW 👍🏻
Hi Will, it shouldn’t really matter. 73
Tim, at any slope angle does the antenna take on a more Vertical or horizontal polarization? At any point of angle may it be a bit of both? A Happy New Year as well Sir -n2qfk
Happy new year! Well it does assume more of a vertical characteristic once it gets shallower as a sloper. I'll have a play around and see. 73
Could you model it fed at the high end? I use an end-fed half wave sloping down at 45' from the top of a 3 story house to a few metres off the ground and it seems to perform very well for a bit of wire, particularly on 10m. But I've never modeled it.
I can check that.
Nice video.thanks for doing it. What about gain broadside to the wire? I have two sloping center fed dipoles, 20 and 10 meters. Top ends approx. 50 feet and sloping about 30 deg. I get a a similar plot as you have it and the broadside radiation is quite nice. I know my example is not and end feed but I would to get your thoughts. Thanks
That’s an interesting example 👍
I'd have thought it wouldn't make much difference to the pattern where the half wave is fed. It's just an impedance issue.
Pretty shallow slope on your example. Assume a taller (~15m) tree and try 45° of slope.
Yep but don’t forget, I assumed a pretty standard portable use case. 73
@@timg5tm941 Sorry, I was assuming somewhere surrounded by trees. 🙂
@@JxH ah I see. Ok I can check that in a day or 2 👍
Does it make a difference if you feed it at the top?
If the current maximum is near the feedpoint then extra height would really help .. depends on length of the wire and the band
Interesting. Does this apply to long wire antennas too?
Well this was a 1/2 wave. Patterns will vary according to wavelength.
@@timg5tm941 I changed from my EFHW to a long wire so I could get 80M. The external tuner does struggle to tune 80M but gets there after a few attempts. The long wire is on a slope from 12M down to about 10M and is fed at the high end.