One factor that is often overlooked in planning a good portable operation is the location's height above average terrain and the surrounding noise level. Dave KG5CCI certainly knows how to pick a good location.
In a very low-noise, high plain area where I operate occasionally (DM95ae/DM985xe,) a short 2 element 2m yagi and 4 element 70cm yagi allow me to operate to the horizon in all directions on all of our current LEO satellites. That antenna choice is not applicable everywhere.
Another factor is the portability of the station itself. In many cases, I drive a vehicle with my portable gear. With air travel, larger yagis or multiple antennas can be problematic. I have had no trouble flying domestically or internationally with a full size Arrow and/or Elk.
I'd opt for a better operating location than bigger antenna almost any day. Larger and more complex stations reduce your ability to be agile and adapt to unexpected situations encountered in the field. Plus, increased complexity creates opportunity for failure.
It is always interesting to read from others how they operate portable. The variations in technique and equipment provides others a stepping stones on which to perfect their own portable stations.
73 Clayton W5PFG
On 1/9/2016 13:35, Lizeth Norman wrote:
Phased Elks work well. Airline portable. 2 pieces of coax the same length and a tee. Only caveat is the horizontal spacing. Any antenna pair could be driven the same way.
Shooting RF up and over the Andes (knife edge diffraction) and taking advantage of ducting are two of the things that I've noticed with this setup.
Fellow at Elk was kind enough to outline what I needed to know regarding this and then push me out to the net to learn.. Look up stacking antennas. Capture area. He thinks the elk has an elliptical capture area. That follows from my in field testing.
It's not about gain (directionality, really), it's about more signal to less noise. Noise levels in the rest of the world are high.
Example: Seaside VHF or UHF. Noise pointing over the ocean is much less, s2. Point inland in any occupied area.. 20+S9. Cavity helps somewhat with AGC lift.
I don't take this stuff to nowheresville without a reason.
Let me tell you about the dxpedition to Vieques that no one heard.
On Sat, Jan 9, 2016 at 2:10 PM, Dave Swanson dave@druidnetworks.com wrote:
Hello Satellites friends and colleagues,
Since I started making videos a few months back of my portable satellite operating, a lot of folks have picked up on the fact that I seem to use the 'Alaskan' Arrow (AKA) pretty often. I also tend to use the AKA for DX contacts and very long distance QSOs which always make it into my movies. Questions about the AKA versus the regular arrow have become by far the most asked topic of me from other operators. Clayton, W5PFG, wrote an outstanding piece on his blog ( http://www.w5pfg.us/2015/10/my-thoughts-about-alaskan-arrow-146437.html ) with his thoughts on the AKA, after his experience with one this fall, that I'd recommend that anyone interested in this topic also go read. Since I don't have a blog though, this is the best forum I have to express thoughts on the matter. If you have no intention of ever operating portable, or are convinced some other design is superior, then feel free to skip the rest of this thread. I'm not trying to make this into anything other than an answer to frequently asked questions I get, concerning the differences between the Regular Arrow and the Alaskan Arrow, and to try and address the 'is it worth it' question that inevitably follows the 'which one should I get' question.
So, to start, the regular arrow is great antenna. I have one, and I use it for 95% of the passes I work. I used my regular arrow for my first QSOs with Brazil, Alaska, Hawaii, Northern Ireland, and England, all of which are between 5000km and 7200km from my home operating spots. It is lightweight, effective, and will suit the needs of nearly every satellite operator out there that seeks a portable antenna. If (and this is a huge if, that's outside the scope of this post, but so so important) you have a nice operating spot that has a clear view of the horizon with nothing in the way. You can easily work all birds in the sky AOS til LOS with the regular arrow, and be wildly successful. If I'm not chasing 7000km+ DX, I'll be on my regular arrow. If I'm hanging my arm out the window while /P in another grid? I'll be on my regular arrow. Backyard 45° SO50 pass in the evening? Regular Arrow. Most of the time, I'm on my regular Arrow. It probably doesn't look that way from pictures and video, but I typically don't document my routine operating.. no one wants to see that, they only wanna see the cool stuff.
So, why do I own and use an AKA with everything I just wrote in mind?
First, I do operate terrestrial VHF/UHF, as well as satellites, from mountain tops. For this type of work I'll physically attach the AKA with only one set of elements installed to my mast, pop it up in the air, and work folks in other grids on 2m or 70cm. If I'm Jeepin' to the mountain top, my equipment has to break down into small enough pieces I can fit it inside, or if I'm hiking, it needs to be small and lightweight enough to carry up on my back. The AKA represents the highest gain, lightest weight, most portable solution that I could find for my style of mountain-topping.
Second, the AKA does have more gain, which is useful for working satellites. It's not a lot more gain, and it's not required on most passes, but I routinely work at < 0.5° in max elevation from elevated positions while portable, and so every db counts. Most people are probably not doing this... and judging by the considerable lack of activity I hear in the birds on these passes, I think there's a fair amount of evidence to support this theory. If you're routinely working exceptionally low passes at and near the horizon portable, then an AKA might be for you. If not, I wouldn't worry about it.
Third, as mentioned many times by others, the AKA is big and heavy. As Jeff, NI3B, said a while back in a post "Holding one of those things up in the air for fourteen minutes and your arms will look like Popeye the Sailor Man at LOS." Combine this with my distaste for tripods, and you can see where we've got an issue. While I don't care much for canned spinach, I am a six-foot, 250 pound man, I split firewood by hand, and I try to keep myself pretty strong and in shape. I can hold the AKA for an entire pass without a huge issue, even thought my arms get pretty sore after. I absolutely understand that others may not be capable, or simply may not want to subject themselves to this kind of punishment. That's fine, you don't have too. Get a regular arrow, and save your biceps.. you'll be just fine.
So in summary, If you're a mountain-top, multidisciplinary operator, that wants superior portable performance, weight and muscle fatigue be damned, then the AKA might be for you. If you're not, get the regular arrow, you won't be sorry.
Feel free to ask questions, provide critiques.
73!
-Dave, KG5CCI
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Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb