Easier to build, versatile, and effective, the K6ARK QRP matching unit kits are now available. Here’s how to build it as an End Fed Halfwave.
First things first, if you’re building one of these kits, be sure to carefully read and follow the instructions at www.K6ARK.com. Kits can be purchased through Amazon. Here are some affiliate links:
Male BNC Kit: https://amzn.to/3G28lfD
Female BNC kit: https://amzn.to/3zhepOq
Build the kit into a matching unit of your choice, add wire, and get on the air.
If you have any questions or issues during your build, please contact me directly and I’ll do my best to help you succeed in your build. Thanks for watching, and have fun with the build!
The Arizona Summit-to-Summit 10 Point Madness event provides a great opportunity to push the limits of 2m simplex and see what’s possible over long distances. Although I didn’t set any new personal records on this trip, some great contacts were made and plenty of fun was had.
The yagi is a homebrew design made from U-channel aluminum, steel hardware, and arrow shaft elements. The matching network is made from parallel 1/4 wavelength sections of 75 ohm coax to transform the 28 ohm yagi impedance up to 50 ohms. Those coax sections are wound a few times through a toroid as a common mode choke.
The boom is about 8 ft in length when extended and folds down to 32 inches. total weight of the antenna is about 2 lbs, and the pool cleaning pole mast adds another 2 lb or so.
n August, I set out with 3 friends from the SAR team to spend 4 days in the hills, building and refreshing our mountain skills and visiting some amazing summits. Afternoon thundershowers limited us to only two summits, but they were fantastic.
First on the list was Thunderbolt Peak at 14,003′. It has an incredible summit with a technical summit block. The next day, we summited Picture Puzzle Peak, a first for me, and a SOTA summit which had never seen an activation.
The team was great, the trip was awesome, and I can’t wait to be back in the mountains.
GEAR I USE:
Cooking and water:
Aquamira Water Treatement: https://amzn.to/3zMl7f0
Squeeze Water Filter: https://amzn.to/3kXgatq (for smaller volumes/on-the-go)
Stove: https://amzn.to/3thCWQp
Food:
Meat Shredz: https://amzn.to/3thD7v3
Canned Salmon: https://amzn.to/3BIFdaA
Couscous: https://amzn.to/3h1UVpp
Dried Oyster Mushrooms: https://amzn.to/3zKy3ln
Freeze Dried Broccoli: https://amzn.to/2WMUU1J
Soup Vegetables: https://amzn.to/3zP2Qxx (good for mixing with other meals for flavor)
Camp Gear:
Backpack: https://www.mammut.com/us/en/products/2520-03831/trion-nordwand-28
Outdoor Research Bivy: https://amzn.to/2YtGynh
Aricxi Tarp: https://www.aliexpress.com/item/32965526071.html?spm=a2g0o.productlist.0.0.4d956ca37vmoLN&algo_pvid=a2178fa8-0827-4432-9603-10c44a2a66f2&algo_exp_id=a2178fa8-0827-4432-9603-10c44a2a66f2-0
Bear Canister: https://amzn.to/3hm0CyH
Every year, the Mountain Rescue Team embarks on trips to the Sierra Nevada to train on technical terrain at high elevations. Each year, I organize a trip that I call Car-to-Car hell. It involves daily climbs up big mountains with overnight car-camping in between. This year, we climbed Laurel Mountain, 11,812′, via the NE gulley (aka Mendenhall Couloir). It’s a 3,000+ foot vertical "easy" 5th class climb. Most would want a rope for protection, but there aren’t many options to place gear, so most just free-solo the route, as we did.
It was a beautiful climb with a bonus SOTA activation at the top. So here’s the story. Hope you enjoy coming along for the climb.
On July 24, 2021, around 1830 UTC, some potentially incredible 2m simplex contacts were made between a station in New Hampshire and about 20 stations in Southern California. Those contacts may have been part of some kind of incredible propagation event. Or they may have been the result of happenstance, via a set of internet linked transceivers at each end of the continent. Check out the video and let me know what YOU think made these contacts possible.
Big thanks to the @SoCal Simplex Archive for allowing me to share his recording as part of my video. Please check out the links below for more of the audio.
First call from NE1B: https://youtu.be/hmuXBf0Himk?t=37670
First NE1B QSO: https://www.youtube.com/watch?v=hmuXBf0Himk&t=37865s
W2CAZ/M CQ call: https://www.youtube.com/watch?v=hmuXBf0Himk&t=38060s
Beginning of about 30 minutes of QSOs with NE1B: https://www.youtube.com/watch?v=JEIOhuhZyYU&t=4335s
Transmission with apparent packet loss: https://youtu.be/JEIOhuhZyYU?t=4419
Every year, the Central States VHF Society hosts a series of Sprint Sprint contests – one of which is a 50 MHz event. It’s a 4 hour contest with a point for each contact, and a multiplier of the number of 4-character grids worked. So I figured, I should probably operate from a SOTA summit for this event.
Spring Sprint Website: https://sites.google.com/site/springvhfupsprints/home/2021-information
Show Chapters:
0:00 Headed up the peak
1:42 Antenna intro
4:00 Telescopic Pole and Extended Double Zepp setup
6:19 Yagi Assembly and Setup
15:05 Contest Begins
21:32 Wrap-up
Not fully satisfied with the size of my 3-element 6m yagi, I constructed a larger one… much larger, actually. It consists of a 4-section 5 meter folding aluminum C-channel boom, and arrow shaft elements. Spread out on the boom are 5 elements which give a theoretical free-space gain of about 8.5 dBd. At 12 ft above ground, with sloping terrain all around on a summit, I expected pretty solid performance. And that’s what I got.
For the contest, I set up two antennas: the yagi, and an extended double zepp – a high-performing wire omnidirectional vertical antenna. I had each connected to an Icom IC-7300 with a coax switch to quickly change antennas. It was awesome switching back and forth to compare signal strengths on each antenna from the same source. The yagi crushed the vertical for longer-range contacts, but closer stations were much more mixed, likely due to signal polarization.
Check out my Amazon store with lots of my favorite portable radio gear: https://www.amazon.com/shop/k6arkportableradio
Toss in some food, a bit of sleeping kit, and that’s about it. Villager Peak, W6/CT-096, is a remote 5,760′ summit with the nearest trailhead about 7 miles away at 900′ elevation.
I had activated Villager Peak before for SOTA, but a nearby summit, guarded by a steep descent and climb from the Villager peak ridge, remained unactivated. My goal for this trip was to activate that summit.
Hope you enjoy coming along for the adventure.
Interested in the gear I use? I have organized a bunch of it into an Amazon store: www.amazon.com/shop/k6arkportableradio
I’ll be operating and streaming live from a local SOTA summit during the YouTuber’s Hamfest. Hope to get you all in the log, and I’ll also do my best to watch the chat for any questions about SOTA.
Please join in on the fun – I’ll be working 20 and 40m which should cover much of the US.
Trying to those last few states, grid squares, or DXCC entities? Want to make a contact with a particular station half-way around the world? VOACAP is an incredible tool to help plan your contact and maximize your chance of success.
As part of the YouTuber’s Hamfest – 2021, I’ll be spending 30 minutes presenting what I’ve learned about VOACAP and how to use it to maximize your odds of that elusive DX contact.
I took the homebrew QRP 1 m diameter small transmitting loop out to a local summit for some fun and was surprised with some fantastic propagation, on 40 meter nonetheless. This was one of my first DX contacts on the band, and with a small compromise antenna and QRP power, nonetheless.
Small transmitting loop antennas are relatively simple and fun to build. Here’s a little helpful info to get you on the right path to building.
Also check out @Amateur Radio VK3YE’s videos here on YouTube – he has done lots of work with small transmitting loops.
Here’s the hardware I use to make the larger part of the loop. Pretty simple bar-stock aluminum folded out straight and then bent into a circle. Works great!
1/16" x 1/2" Flat Aluminum Bar: https://amzn.to/3trTdAX
Mini project box: https://amzn.to/3h8FeNP
6-32 x 1/2" Stainless Screws: https://amzn.to/3tmqI7G
6-32 Nylock Nuts: https://amzn.to/33lLnyj
#6 Flat Washer: https://amzn.to/3h9YJWy
Feeding and matching a loop takes a bit of trial and error, and some specific electrical components – primarily variable and potentially also switched capacitors that can handle very high voltage and currents. Study up before you build to optimize your design.
If there’s interest, I can create some videos that go more into my strategy for building and matching these types of antennas. It’s a fun build!
