Is Elecraft AX1 antenna efficient? It depends on mounting!
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- เผยแพร่เมื่อ 26 พ.ย. 2024
- Many Ham Radio portable operators owning the Elecraft KX2 transceiver also have a super-compact AX1 portable antenna. It is a base-loaded short telescoping whip with just some 115cm of antenna body in the air. Lots of hams use it in a walkie-talkie style mounted directly to the BNC connector on the radio. Sometimes, operators don’t even use a single radial supplied with the kit. It’s a big mistake! In this video, I make a small experiment with two different mounting styles of the AX1: a “ walkie -talkie” style with one radial vs bike-mounted style with 3 radials on the ground. The Reverse Beacon Network reports surprised me!
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73! @Linas_LY2H
It's great to see a tester using CW on these antennas !!! ..... I've seen many reviews on the AX-1 and will be getting one for my portable CW and FT8 efforts .... thanks !!!! de George , N2JNZ
Linas... I haven't had the success I'd hope for from my AX1... Your video illustrates how ground radials can make a significant difference in RST. Bravo, on the tuning knob... I have a nicely machined aluminum knob... it's too big really, so I went back to the factory knob. Thanks again and 72! de W7UDT (dit dit)
Thanks Rand! Yes, it's a compromise antenna, but lots depend on propagation. Even with one radial dragging behind I've done numerous contacts, especially on 17m, conditions permitting. Actually, it's even more fun when making a QSO with such a minimalist set-up and when you get it done!
The knob I printed out is actually the same diameter, just a bit taller and with a finger dimple, makes tuning more comfy. Aluminum would be nice, but as you say, the ones I saw all were too big, and, probably, too heavy which could disbalance the encoder's shaft with time. 73! Linas LY2H
Thansk for sharing this experiment! How much influence do you think having your body so close to the antenna has in disturbing the system in the "walkie-talkie" configuration? Also, would having 3 radials dangling instead of 1 in this configuration make any difference?
Thanks for watching my experiments and conducting your own!
Human body is a lousy radial but it can work as such, at some extent, if no wire radials at all are used. Usually , it's a stray capacitance between the radio and the ground which provides the necessary return path for the radiated signal in addition to the humam body. My experience is, that if at least one radial is used, the human body makes no significant influence to the whole antenna system ( with antenna tuned and low SWR) . Three dangling radials would certainly (IMO) make the overal performance much better than one radial or no-radial-just-body configuration. Have fun! 73! Linas LY2H
There is no common mode choke at the AX1 feedpoint, so there is a very good chance the attached 2m coax cable acts as an element of the antenna and helps improve the sig.
73 Gerd Df9TS
Linas. Thank you. Am going overseas with KX2 but only have room for small antenna. Thought I would use the AX1 mounted on a camera tripod with one radial. Sounds like 3 radials with small diameter wire would work ok. 73 de K4RLC Bob
Yes, sounds like that. Have a nice trip and great time with your radio Bob! 73! Linas LY2H
I shall "borrow" your idea... using watson mobile antenna on my e-tricycle when out and about.
I also have an ild Hanimex photo tripod which I might try as well.
TNX 73
You are most welcome! I'd love to see your antenna installation on your e-trike, as I also have one ( for QRO operations :)! 73! Linas LY2H
Linas. Thanks for video. Interesting test. I wonder if you tested the antenna in walkie talkie mode with 3 radials. It could be that it’s the radials that improve performance, not the mounting. Eg both tests should use 3 radials.
Thanks for the comment Pat! I think, you are right, it's the radials which make difference, then only mounting. But the goal of this experiment was to compare situations of typical use: one typical being walkie-talkie with one dragging radial, the other typical - tripod-mounted (bike-, table-, bench-) with typically 3 radials. So, comparing 3 radials in the walkie-talkie style would not be a typical situation, accordingly to my way of thinking :). But of course, it's totally possible and would bring much better results than one-radial, or no-radial ( or "I am the radial") scenario. Well, may be it's a food for thought for some other sunny afternoon experiment... Stay tuned! 73! Linas LY2H
@@Linas_LY2H Hi Linas. I have used the AX1 both ways but have never used RBN to check the strength. I usually attach the 40m and 20m counterpoise so I can change bands by adding or removing the 40m coil. I never thought to add a third radial. What length radials do you use? In any case, the AX1 does get results. I've used it for SOTA or POTA when I can't put up a wire antenna, and I always get 30-40 QSOs. So even though it's a compromise antenna, it does work adequately. Thanks again for the great video.
Great performance Pat! 30-40 QSO is a solid score. My radials are cut 6m each so I can adjust the length in case I need to. But radials lying on the ground don't need to be resonant, the quantity is more important with 3 being the very minimum, and 16 being the practical limit after which further increase in number does not bring justified improvement in performance compare to the increase in costs and labour to install them... Have fun experimenting! 73! Linas LY2H
Great Video. I have learned something new. Thank you for that. The mini bike you are using seems to be pretty awesome. May I ask what model / brand this is? Thanks again.
Thanks for watching! The e-bike is a Woosh Galego with 250W front-wheel motor and 3-speed enclosed gear box in the rear. HTH, 73! Linas LY2H
Labas Linai,
Andrius KE2AXD
Labas, Andriau, malonu matyti lietuviškus vardus su JAV šaukiniais! 73! Linas LY2H
Great video. What is the length of the 3 radials used? The single counterpoise wire provided with the ax1 is 4 meters btw.
Thanks for the correction, Martin! Yes, the stock c'poise wire is almost 4m long. My own 3 radials are cut for 6m each so I can make adjustment if I need to , by winding them a little bit up. 73! Linas LY2H.
Linas - Thanks for another great video. I wonder if your result for the walkie-talkie test was affected by holding the AX-1 at an angle vs. vertical, as during the bike mount test. KN6WKM
Hi Kevin, thanks for a good question! Operating the walkie-talkie style I was NOT standing in the same position and keeping the whip at an angle all the time during this ~5 min slot of transmitting. It's only in this ~30 seconds episode I put in the video it seems like that :). In the reality, I was moving myself a bit, changing the angle of the antenna, keeping it a bit higher, a bit lower than the bike's seat- immitating a normal "pedestrian mobile" behaviour. And the behaviour, as well as my body's impact, is a part of an antenna configuration in this case. My goal was not to mimic the tripod, but the opposite: to compare a stable on-the-bike plus 3 radials configuration vs dynamic "walkie-talkie" style. So, I don't think the RBN report was much influenced by this short time of antenna at an angle, I consider it a holistic report mirroring the realistic situation, actually. 73! Linas LY2H
Thanks for the experiment good results.
Interesting experiment, thanks. good video showing the process, also.
I have enjoyed similar successes using a home brew vertical - usually coil-loaded, especially on the beach in various places and even in other countries (Malta/Gozo especially). No need to buy an aerial (I detest buying aerials!) they are so easy to make even if you’re hamfisted and have few tools, a length of wire on a pole will do fine. The radials are key, though, elevate them if you can, even if you just lay them on top of the grass or bushes. 73/72 es gud DX, Les G0NMD always QRP (edit) I forgot to say Slava Ukraini 🇺🇦
Thanks Les! 100% with you on homebrewing antennas, especially wire ones! But if it's a YAGI, or a multiband vertical - sometimes it is hard to achieve just a mechanical quality not having right quality materials and machinery at hand. Simple verticals, 3D printed coils- yes, I love this DIY! As it comes to AX1, I bought it of pure curiosity as I like the high craftsmanship of Elecraft :) 73! Linas LY2H
Expensive garbage. Avoid.
The only accurate way for this test is to call Cq for the same amount of time on both tests and move vfo up one to test on the bike after being down one k holding radio in hand. Also needs to be done asap between testing.
Thanks Jay! That's , actually, exactly what I was doing , even the QRG :) The RBN is very convenient that it displays on the same page, chronologically, all my CQ attempts, so I can see and compare my reports very comfortably. 73! Linas LY2H