Nashua ARC will be hosting its first Youth Outreach event on Saturday, October 1 from 8am-2pm at Mine Falls Park in Nashua, NH. Mine Falls Park is located on Whipple St.
Mine Falls Park hosts many youth soccer games every Saturday throughout the Fall. We are hoping to take full advantage of that fact in order to provide kids a bit of insight into what comprises amateur radio.
Some of the activities that we will likely host are:
Get-On-The-Air (GOTA) Station
Fox hunts
Use some HT’s and get on the Nashua repeaters
This we hope is to generate enough interest so that we can plan a follow-on activity a bit later.
Now comes the part where AB1ZO looks at you warmly, scratches his cheek, and asks you for a favor. It might go down something like this:
A friendly, casual conversation between me and you
And that favor is that we really do need your help to come out to the Park:
Help us set up beginning around 8 am
(Setup is pretty important to have able bodies around for. We’ll shoot to get on the air as quickly as possible after. Perhaps by 9 am)
Work the booth
(Most importantly) Interact with the kids.
Help breakdown around 2 pm
The more the merrier and the longer you’re able to give a bit of time, the better as well. Additionally, you are completely encouraged to bring family and friends, especially if they are < 18 years old. But in all honesty, I think it would be fantastic if we had a significant contingent of the club at the Park, to welcome our guests. But don’t do it for me, do it for the kids:
Do it for the kids…
If you think you can give some time, please contact myself ([email protected]) or Jamey (KC1ENX) to let us know what you would like to help with. Again, we really could use the volunteers in all the aforementioned areas. We’re hoping this is a facet of the club you will all embrace as it evolves.
A few months ago, I wrote an article on building a stealth antenna farm. Since I live in the land of CC&Rs, antennas must be “dual use” such as a vertical hidden inside a PVC flagpole, or low dipoles and inverted Vees hidden in trees. I spent many years as an avid contester and DX-chaser to appreciate the logic of stacked beams on towers to enhance the thrill of the hunt. Thanks to Layne, AE1N, I checked out the website of Jeff, AC0C (www.acoc.com) for some ideas of how to build a multi-band station in one’s attic without the condo association vigilantes running him out of town. Jeff spent countless hours crawling around his attic to construct multi-element antennas for 160 through 6 meters. Spurred on by Jeff’s success, I decided to explore the attic of my garage to see what I could do. As I described in the MAY Nashua ARC bulletin, I settled on building Moxon antennas for 15 and 17 meters.
An old adage about antenna building states that an antenna must be built-in lousy weather in order to work right. Thirty years in New Hampshire lent credence to this axiom as I spent many a cold, windy day on a tower doing antenna work. In Florida, a similar law applies: build an antenna in the summer months while sweating profusely rather than during the comfortable winter weather. Again this makes sense: DX and contesting fill up the winter months to have time to mess with antennas. It is also important to remember that, during such endeavors, you will become enamored with you antenna as you take breaks to warm your body (in NH) or drink a gallon of water (in FL), all the while cursing this law of antenna building.
But I’m getting ahead of myself. My garage attic is roughly 20 x 20 feet with an apex of about five feet that runs north-south. I had selected the Moxon design because a conventional 2-element beam would not fit in the space available. I elected to build a Moxon for 15 and 17 meters that would fit in the space available without having to encounter obstacles like the ventilation duct work. I was also fortunate in that my home is one of the older models that do not have foil-backed insulation inside the roof that creates a radiation-proof box. The joists junctions are reinforced with metal plates as part of hurricane building codes. My plan was to attach the wires to the roof trusses and stay away from these plates as much as possible to avoid interaction.
The 17-meter Moxon is a little over seven feet between elements while the 15-meter Moxon is about six feet between elements. I used a piece of half-inch PVC pipe as a template to mark the joists for the 17-meter antenna. The antenna is about 2.5 feet above the attic floor for a total height of eleven feet above the ground. I had modeled it at 13 feet so I figured it would be close enough. The 15-meter Moxon is about 15 inches above the 17-meter one. When viewed from the top, the antennas look like concentric rectangular loops.
Over the course of several weeks, I grunted, groaned and sweated my way back and forth measuring and installing the wires. I worked during the morning hours before I was soaked before 10:00 AM. I found myself wishing I could have my five-year-old grandson help me. He can stand upright and is plenty flexible to maneuver around the joists. While I did not have to worry about the obvious safety issue of working on a tower, I did at times feel I was a candidate for the NFL concussion protocol from bumping my head. I tried using my cycling helmet but it interfered with my headlamp. Another similarity to tower work is that I had to make N trips back and forth in the attic for stuff I forgot. This is, however, much more bearable that climbing up and down a tower to get what I forgot.
Figure 1 shows a view toward the south end of the attic. The two pieces of PVC form the element separators for the 15-meter Moxon (top wire) and the 17-meter Moxon (bottom wire).
Figure 2 shows the reflector elements for each antenna as secured to the joists, looking north through the attic. The white standoff fasteners are coax cable tie-downs that I found at the hardware store. Standard house wiring fasteners would have worked but they leave little room for pulling wires if I needed to make adjustments. (My first attempt was to use duct tape to hold the elements up. However, the heat soon made them droop.)
Figure 3 shows one corner of the director of each antenna looking east. The duct work to the left is part of the ventilation system while the open duct vents directly from the garage below. The yellow fence standoff on the upper antenna is the bend point for one end of the 15-meter director. Not visible to the left is a similar bend point for the 17-meter director.
Figure 3 – Looking East-from the Reflectors
Figure 4 shows the temporary feed points for each antenna.
Figure 4 – Feedpoint for 15m (top) & 17m (bottom)
The figures above show the project to date. I installed the 17-meter antenna first and measured its SWR performance with my analyzer. I found that it resonated beautifully at 16.7 MHz with a 1.1:1 SWR while bulging to 3.9:1 at 18.1 MHz. I shortened each element by a foot and ran measurements again, this time the resonant point moved up to 17.3 MHz (1.3:1 SWR) and the SWR at 18.1 MHz dropped to 2.7:1. I folded the elements back another four inches on each end and measured the response. I observed the SWR bottoming out at 1.5:1 at 18.1 MHz where I wanted to be. As a point of interest, I modeled a Moxon designed for 16.7 MHz and noticed the elements were about two feet longer than a Moxon designed for 18.1 MHz, close to the twenty inches I had to shorten the elements. Apparently, there is some interaction with the wiring that runs along the attic floor near the edges.
Armed with the satisfaction I was on the right track, I installed the 15-meter Moxon above the 17-meter antenna. I hooked up the analyzer and fired it up only to find to that its “resonant” point was a dismal 3.0:1 SWR at 22.9 MHz, rising to 3.9:1 at 21.1 MHz. This meant my antenna was too short. I went back to EZNEC, opened the standard dipole model and plugged in 22.9 MHz and found that its length was very close to the overall driven element for a Moxon designed for 21.1 MHz. I lengthened each element by five inches as a starting point to see what would happen. The result was no change in SWR at 22.9 MHz while dropping slightly to 3.6:1at 21.1 MHz. Hmm, looks like I need to get a little smarter about this.
Stay tuned for Part 2 to find out. (Don’t you hate that?)
I suppose the title could also be: (or how I learned to stop procrastinating and finally put up my HF antenna).
Well, I did it. I finally got my HF antenna up after months of admiring it through the plastic wrap and having the world’s most expensive paperweight (IC-7300) sitting in my metashack (how could I really ascribe any reality to it when it was still merely a concept). What I would like to accomplish in this article is not only a description of the construction etc. but also of some mental gymnastics, I had to do in order to get to the finish line.
Way back in February, I was able to get my General license. I was pretty stoked (to use the common tongue) and looking forward to getting it up and going. This required, essentially, two things: a radio and an antenna. Easy-peasy, right? The first really was easy. I wanted a 7300. Who didn’t? The proverbial ICOM bandwagon drove by my house daily. Several times a day while banging on a few drums. So, I did my homework as best as I could, talked to a few folks, and with not much arm twisting, bought a rig. Now I needed the antenna. And some drums…
For this portion of the ordeal, I ended up doing my homework a little more. I spoke to Fred and Anita at length about their choices: read their blog, saw their own setup in person, read posts in the Elmering session of Nashua ARC’s website, read comments on eHam.net about various antenna types. Some factors to consider are — in no particular order:
Budget
How much help you will have to put this up
Aesthetics
Available real estate
How many bands do you want to work
At my QTH in MA, I have 0.5 acres in the front and back.
I think the price point was a bit north of 300 bucks. Having made up my mind, I didn’t do anything about it. Upon reflection, I think I really didn’t act because work consumed me until mid-May. I literally had no free weekends for months, so there was no rush. In the interim, Fred and Anita had opened up their station for use, and I took joy in hearing about others’ QSOs for a while.
In order to still feel like a HAM, however, I decided to take my Extra exam in May. Once I that got out of the way I bought the Buckmaster in June on one fateful Thursday afternoon, and again, there it sat in the meta shack until September. Excuse #2: Honestly, with a project this big (at least for me) I think I was a bit gun-shy to get it up. I felt unqualified to do it; maybe even afraid to fail amidst all these competent people in the club.
Up until now, this may have read as Dear Diary, so let’s get to some actual station construction! Labor Day weekend was the ticket.
Good grief was this tough! Probably 85-90% of the total time was spent trying to figure this out. Mainly because, looking at the graphic, I had to get this about 35 ft. in the air. I got frustrated pretty quickly…
Buckmaster OCF dipole installation picture. Right from their website
Now maybe that doesn’t seem like it’s that high, but I assure you, it becomes pretty darn high when you keep failing. So thinking about the problem and researching on the internet led me to some methods to try to get a rope up in the tree:
Use a potato gun
Call folks from the club to come lend a hand
Rent a scissor lift from Home Depot
Use a bow and arrow
Use rope tied to a rock or stick and try to launch over the branch I want.
Here was what the jury decided on each of these options:
Built one! Fires really well, but had issues initially with sparking it in the combustion chamber. Turns out the reason was due to insufficient amounts of butane getting into the chamber. In any case, I abandoned this as a choice. But who’s to say I can’t be mischievous at a later date.
I felt bad bothering folks despite one ethos of amateur radio is to Elmer each other, so I didn’t ask for help. Bad news bears to those of you in the same predicament.
Too expensive for the little time I needed it. I think Home Depot (spelling error intentional) wanted something in the neighborhood of 200 bucks or more.
Don’t have one and nearest friend with one lived in Carlisle. Would have to work around his schedule and at this point, I was thru being patient.
Rock idea worked reasonably well, but honestly, the best option was to get a stick and tie nylon fishing line around it. I have a pretty good arm it turns out, so I tied fishing line around the stick and started throwing.
In full disclosure, the elimination of these options takes us from Friday to Monday. Wisps of steam could be seen emanating from my ears.
The stick was attaining the requisite height and hitting where I needed it to. The huge snag (no pun intended), though, was the fishing line was getting caught in the branches on the way down. Yet another problem. Cue engineer father-in-law. He’s the guy labeled “this guy” in the picture.
Helper Dude
He recommended winding a large amount of fishing line around the stick (but not all of it so that there would still be some left over on my side of the branch) so that when it came down the other side of the branch, it would unravel and not be as likely to get caught. This worked like a charm!
With the fishing line on either side of the branch, we tied the actual nylon, water / UV resistant rope (which I picked up at Home Depot) somewhere 25% up my side of the fishing line and then got on the far side of the branch and began hoisting it up. This also worked out very well.
Same father-in-law and hanging ropes which will support the Buckmaster
Finally, with the rope I actually want to use over the tree, I tied the Buckmaster to one end of the rope on my side of the branch and then raised it up. I lowered and raised it a few times to make sure it wouldn’t get caught in the tree at any place. I tied off the free end through an eye screw that I screwed into the tree.
The coax I used was LMR-400. Again, doing my homework, I decided to splurge and buy 200 ft of coax but without the PL-259 connectors. I did this because I wanted to be able to cut the coax where I wished and would subsequently learn how to attach the connectors myself. This too turned out to be a relatively easy job. I picked up some connectors at the Boxboro Hamvention and borrows Dave’s (N1RF) crimper set (with dies) to attach the connectors. Taking my time, I was able to do both ends of the 200 ft coax in about 30 minutes tops. I also purchased some Super 88 electrical tape from Home Depot as well as used Scotch’s 2228 Moisture Sealing Electrical Tape (some other folks use CoaxWrap) for weatherproofing. I applied this following Fred’s suggestion on his blog.
Layers of super 88 and weatherproofing electrical tape fastened to antenna connection point
With the feed-point setup, I then purchased two more nylon, water/UV resistant ropes to connect to the Buckmaster’s insulators. I found that the 3/16” diameter by 100 ft. rope worked well (3/16″ fit nicely through the insulators’ 1/2″ holes), again purchased at Home Depot. Shirley, the cashier, shot me a smile after ringing me up for the umpteenth time. To temporarily tie these off, I terminated the rope through some more eye screws I screwed into trees in my yard. But for the final installation, I will again follow Fred’s advice from his blog post.
Then, I ran inside, ran the coax through the window thereby performing the transformation of the meta shack into a proto shack! (Proto because it’s in the process of getting changed and upgraded) Ta da! Prestidigitation! That night I worked Brazil and the Czech Republic on 20 and 40 m respectively, and Australia around 0615 the next morning on 20m.
Protoshack. Coax not shown.
My follow up projects:
I never mentioned grounding. I do have an 8 ft copper ground rod that I will install. I bought lightening arresters from DX Engineering: I have the kind that allows the passage of DC voltage which is needed for utilizing an antenna switch down the road. Since I plan on buying an antenna switch later, this seemed like a good option. This entire installation will take some time, so I need to find a free weekend. For now, I am only operating when the skies look perfect!
Install my 15 m dipole that I bought from the HRO and covers the band not covered but the Buckmaster. This will likely happen in the Spring. For reals.
Track down RF interference sources in my home and install the necessary chokes and beads. I’m kind of looking forward to this step.
Find a final resting height for the radiating wires of my Buckmaster. I have a cousin with tree climbing equipment. Once he comes over to trim some branches etc., I am going to try and make a 180-degree angle with the wires as best as I can. Additionally, my wife wants me to switch out the white, nylon, water/UV resistant rope with dark colored rope since it’s a bit too visible.
Once I got going, I really had a blast. If I can be of any help to anyone about this, please feel free to send me a reply or contact me on the club website. Thanks a lot for following me through the whirlwinds that are my thoughts, and see you on the air!
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