Tag Archives: Chameleon CHA MPAS Lite

Chameleon MPAS Lite: Using the coax shield as a counterpoise and how this might affect directionality

Many thanks to Dale (N3HXZ) who shares the following guest post:


Portable Operation Using a Vertical Antenna Without a Counterpoise Wire!

by Dale (N3HXZ)

In a previous article that Thomas was kind enough to post, I ran experiments to determine if the counterpoise wire orientation of the Chameleon MPAS LITE antenna system in the vertical configuration in any way shaped the antenna pattern.  The configuration of the antenna is shown below.

The system consists of a 17’ telescoping whip antenna, a matching transformer, a 50’ coax cable with an in-line RF choke, and a counterpoise wire (60’ long, but unwound to only 25’ for use in the vertical configuration).

Subsequent studies I performed have reinforced my earlier conclusions that the positioning of the counterpoise wire in this setup does not appreciably shape the antenna pattern. One of the comments from my post came from Stephan (HB9EA). He commented on the fact that the coax cable is indeed a counterpoise via the coax shield and that in fact my system set-up had two counterpoises.

It was Stephan’s comment which led me to contact Chameleon Antenna to discuss counterpoises with the MPAS LITE antenna in the vertical configuration. I communicated with the Director of Research and Development group at Chameleon and found out some interesting information that I wanted to pass on.

He mentioned that the system can be used with the coax cable acting as the lone counterpoise as long as the coax cable is at least 25’ long, and preferably 50’ long.  The coax should be spread out and not coiled along any portion of its length. It was stated that the counterpoise wire provided with the product should be used with short-length coax cables.

With regards to a counterpoise orientation shaping the propagation direction, he stated that it is generally accepted that using only the coax as a counterpoise tends to have the antenna pattern slightly favor the direction in which the coax is laid out. Adding the counterpoise wire in a direction opposite to the coax would tend to balance out that pattern. Having the coax and counterpoise wire at some angle to each other introduces variables that make it difficult to determine the antenna pattern.

My initial study had the counterpoise wire oriented at an angle to the coax cable.  I mentioned that my initial study showed that orientation of the counterpoise wire did not seem to appreciably shape the antenna pattern, and he agreed. What is unknown is the overall degree to which the coax cable shapes the antenna pattern with or without use of the counterpoise wire.  This is an area I am currently investigating.

Operating the MPAS-LITE vertical configuration with only the coax cable as a counterpoise was an intriguing thought.

To test it out I teamed up with Jim (KJ3D) for a SOTA activation on W3/PT-003 (Seven Springs). We both deployed the MPAS-Lite with only the supplied 50’ coax cable attached. Coax cables were laid out in a straight line. One cable was oriented southeast, the other one oriented east. We operated on 10 Watts in CW mode. The activation successfully worked all bands from 40M to 10M. I operated an Elecraft KX2 and Jim operated a KX3. The internal tuner of both rigs easily obtained a 1:1 match across all bands.

A map of the QSO’s is shown below. Note that despite the coax cables facing to the southeast and east, we easily worked stations in the opposite directions. Hence any minor shaping of the antenna pattern by the coax orientation does not appear to impede successful communication in all directions.

In summary, the MPAS-LITE antenna system in the vertical configuration utilizing the 50’ coax cable with an in-line RF choke as the single counterpoise has been demonstrated to perform well in the field.

For portable operation where fast deployment and simplicity is paramount, using the furnished coax as a counterpoise is a quick and dirty way to get the antenna erected and on the air with reliable communication capability. Eliminating the counterpoise wire allows for quicker set-up and tear-down, and one less thing to put in the backpack!

Choosing between the Chameloeon MPAS Lite and Chelegance MC-750 vertical antennas

The Chameleon MPAS Lite

Over the past few months I’ve been asked by a number of readers and subscribers about the differences between the Chameleon MPAS Lite and the Chelegance MC-750.

More specifically, folks who are looking for this type of portable HF antenna want to know which one they should buy. I have difficulty answering questions like this in an email or comment because I need to understand the operator first.

At the end of the day, both of these antennas are excellent choices; the decision has more to do with your own personal preferences and how you see yourself using the antenna.

Why buy a vertical?

The Chelegance MC-750

I believe every serious field operator ought to have at least one vertical antenna option available. Depending on where you’re operating, verticals might not be the highest-performing antenna you could deploy, but they may be the most convenient and rapid to deploy. Then again, if you’re sitting on the beach at the ocean or sea, a vertical can be a phenomenal DX antenna.

Verticals aren’t terribly difficult to build. In fact, one of the first field antennas I built many years ago was a 20 meter vertical, albeit with wires instead of telescoping whips.  That said, it’s difficult for some of us to build something as high quality and as durable as a commercially-produced vertical antenna system.

Both the MC-750 and MPAS Lite antennas are high-quality and very quick to deploy. I reach for them frequently because I often have only a short time on the air and any time saved setting up the antenna usually leads to more SOTA and POTA contacts.

MC-750 / MPAS Lite Comparison

Instead of writing a full article about the differences, I made a video where I discuss these two antennas at length. My focus and goal being to help those who are trying to make a purchase decision.

At the end of the day, I don’t think you could go wrong with either antenna system, but I do do think one may suit you slightly better based on your operating style and goals.

Enjoy:

Video

Click here to view on YouTube.

Below, I’ve also listed some key features and specs of both antennas along with links that you might find helpful:

Chelegance MC-750

  • Price: $179 + $50 shipping (via Chelegance)
  • Whip length: 5.2 Meters/17.06 Feet
  • Counterpoise: Quantity of four 11.48 foot counterpoises
  • Frequency range: 40M – 6M
  • Resonance markings: Yes (save 30M and 6M on current version)
  • Carry case: Yes, padded case included with purchases
  • Product manual (PDF)
  • Product Link

Chameleon MPAS Lite

  • Price: $360.00 (via Chameleon)
  • Whip length: 5.18 Meters/17 Feet
  • Counterpoise: 60 feet of tinned copper KEVLAR PTFE
  • Frequency range: 160M – 6M
  • Resonance markings: No
  • Carry case: No (Optional large backpack from Chameloen)
  • Includes 50 feet of high-quality coax with inline RF choke
  • Product manual (PDF)
  • Product Link

POTA/SOTA Activation Video Playlists:

Spring Flashback: Pairing the Elecraft KX2 and Chameleon MPAS Lite at New River State Park

This year, it’s been a challenge for me to keep up with field reports that accompany my activation videos.  It’s been a very busy year with a fair amount of travel, DIY projects, and family activities.

I recently realized that I have a number of activation videos from much earlier this year–videos I skipped over in order to post some of my Canadian field reports while I was still in Canada (at one point, I was over 2 months behind posting field reports and activation videos!).

I’ve often said that even if only a handful of people enjoyed my reports and activation videos, I’d still post them. I feel like they could even play a small part in someone’s path to doing field radio or learning CW, it’s wort it.

Plus, I occasionally like looking back at them myself.

In a sense, these reports are my travelogues and they bring back memories of some beautiful spots where I’ve played radio, gone camping, and enjoyed time with my family.

So why don’t you join me as we travel back a few months to…

Springtime

Photo by K4TLI

In late April 2022, I took my family on a camping trip to New River State Park here in North Carolina. You might remember this post and a couple field reports from that trip.

In short, it was an amazing trip and I got to play radio quite a bit!

Each day, I played radio from the morning into the evening. The camp site was actually ideal for playing radio. Until…

Saturday morning (April 30) I woke up, made some coffee at the picnic table, then fired up my radio. It was then I learned that one of the new RVs that joined the campground Friday evening brought some sort of RFI-spewing device with them.

I’ve no clue what it was. If I were to venture a guess, I’d say it was likely something used in electronic warfare. It was intense.

At the campsite that morning, I couldn’t copy a single signal that wasn’t S9+ on my meter. The noise level was S8 or S9.

I decided that I’d need to move to a different part of the park to play radio after breakfast and our family’s morning hike.

Fortunately, there was a large picnic shelter within a short drive of our campsite.

I had the whole place to myself! Continue reading Spring Flashback: Pairing the Elecraft KX2 and Chameleon MPAS Lite at New River State Park

POTA Plan C: Swapping antennas and rigs at Tuttle Educational State Forest

After the success of my previous day’s activation at Fort Dobbs State Historic Site, I decided to take the Icom IC-703 Plus out for yet another activation.

As I mentioned in the previous post, the IC-703 has not gotten a lot of outdoor time this year because I’ve had issues with the electronic keyer locking up when using the radio with end-fed antennas.

Of course, there are a number of ways to mitigate or radiate the RF that could be coming back to the radio, so at Fort Dobbs, the previous day, I used a simple common mode choke. It seemed to do the trick.

I was curious if using a common mode choke might be the only solution needed to solve this problem, or if I’d need to perform a mod to my IC-703.

I was ready to test the IC-703 again.

I had a fair amount of antenna options in the trunk of my car, so on the way to Tuttle Educational State Forest (on Friday, October 7, 2022), I considered a few options to shake things up a bit.

Since I was feeling comfortable that the common mode choke was taking care of things, I decided to push the limit a bit and deploy an end-fed random wire antenna. I didn’t have any of my mini portable 9:1 random wire antennas in the car (PackTenna, Tufteln, etc.), but I did have another solution: the Chameleon MPAS Lite.

The cool thing about the CHA MPAS Lite is that while it’s primarily designed to be a vertical antenna with counterpoise, it can be reconfigured and deployed a number of ways including as a simple end-fed random wire antenna.

After giving it some thought, I decided it might be fun to deploy it as an inverted V random wire. In fact, here’s a diagram from the MPAS Lite manual of exactly what I planned to do.

I’d be using the MPAS Lite counterpoise as the radiator, so I wouldn’t have the optional second counterpoise as seen in the illustration above. That’s okay, though, because I was feeding the antenna with Chameleon’s 50′ RG-58C/U cable with in-line choke; the shield of the coax would act as the antenna counterpoise.

This is the same coax cable I used the previous day. Continue reading POTA Plan C: Swapping antennas and rigs at Tuttle Educational State Forest

Fickle weather during an early morning activation at Parc de la Rivière-du-Moulin, Saguenay

Each time our family spends the summer in Québec, we make time to visit the Saguenay region  which is just a couple hours north of Québec City.

We enjoy the hikes, the river walks, and other outdoor activities. It’s a beautiful part of Québec.

This year, we spent more time along the north shore of the St. Lawrence visiting Baie-Comeau and later camping and whale watching a little north of Tadoussac. We also explored more of the Charlevoix region and even parts of the Québec City area we’d never visited in the past. I really enjoyed driving some new-to-us back country roads.

A couple weeks before leaving Québec, we took a family poll and unanimously decided to squeeze in a trip to Saguenay despite our other travels.

Due to other activities we’d scheduled, we only had a window of a couple of days to make the trip. The weather didn’t look that wonderful for the drive north and, in fact, it wasn’t. We drove along a line of torrential rain that was so heavy at one point, I (along with many other drivers) pulled off the road to wait out the heaviest bit.

Otherwise, the drive was/is a beautiful one through the Jacques-Cartier  National Park on 73/175 North. Had it not been for the thunderstorms and rain, I would have taken a small detour to make at least one activation.

The first day in Saguenay was all about walking on the river, and hitting some of our favorite spots when the rain finally moved on; I didn’t attempt a park activation. I decided instead to do an early morning activation the following day (July 22, 2022).

Finding a park

You may have noticed that quite a lot of my activations in Québec have been ATNOs (All-Time New Ones). I didn’t specifically set out to activate ATNOs–in fact, they were hard to avoid because there were so many.

Not so in Saguenay!

POTA activators in Saguenay are an active bunch and they are spoiled for choice in terms of the density of parks; there are so many!

It really pleased me to see so many previous activations at the parks I researched–not only activations in the summer months, but also winter (and they have proper winters in Saguenay/Chicoutimi–!).

There were so many parks to choose from, I decided I would simply choose the one closest to our hotel and that turned out to be Parc de la Rivière-du-Moulin.

It was so close to our hotel, I could have easily walked there.

Continue reading Fickle weather during an early morning activation at Parc de la Rivière-du-Moulin, Saguenay

SOTA in the Clouds: Pairing the Elecraft KX2 and MPAS Lite for brilliant QRP fun on Craggy Dome!

Although I live in the mountains of North Carolina and am surrounded by SOTA summits, it’s much easier for me to activate a park rather than a summit.

Parks can be quite easy: find the park on a map, drive through their main entrance, find a good picnic table to set up, and next thing you know you’re on the air! Of course, wildlife management areas and game lands can be more tricky, but typically you can drive to the activation site.

Summits–speaking as someone who activates in North Carolina–take much more planning. If it’s a new-to-me summit, I typically need to:

  1. find the GPS coordinates of the true summit
  2. map out the drive to the trail head
  3. read through previous activation notes (if they exist) to find out
    • what type of antenna/gear I might pack
    • and any notes I might need to find the trail or bushwhack to the true summit (quite often published, well-worn trails don’t lead to the actual summit)
  4. look up the trail map and make sure I have a paper and/or electronic copy
  5. pack all needed gear for the hike, activation, and emergencies
  6. sort out the time it will take to travel to the site, hike the full trail to the summit, activate, and return home

If you ask most any SOTA activator, they’ll tell you that the planning is part of the fun.

It really is.

One summit I’ve had on my activation list for ages is Craggy Dome (W4C/CM-007). Out of the higher summits in this region, it’s one of the easier ones for me to reach from the QTH. In fact, as with Lane Pinnacle, I could simply hike from my house directly to the summit (although one way to Craggy might take the better part of a day). The trailhead is about a 50 minute drive, and the hike about 30 minutes.

SOTA notes and All Trails indicated that Craggy Dome’s trail isn’t always easy to follow and that it’s steep and slippery.

Craggy has been activated loads of times, though, so I wasn’t concerned at all.

Living here and knowing how much brush there was on the manway to the summit, I knew that Craggy would be a pretty easy summit if I could activate it after the parkway re-opened for the spring and before the mountain “greened-up”; about a five week window.

Meeting Bruce

My schedule opened up for an activation of Craggy Dome on the morning of April 21, 2022 and I was very much looking forward to it.

I wouldn’t be alone on this hike either. Bruce (KO4ZRN), a newly-minted ham, contacted me and asked if he could join me on a hike and simply be an observer during a SOTA activation.

Fortunately, timing worked for him to join me on this particular SOTA activation. Continue reading SOTA in the Clouds: Pairing the Elecraft KX2 and MPAS Lite for brilliant QRP fun on Craggy Dome!

A quick roadside activation with the Elecraft KX2 and CHA MPAS Lite

There are days when I leave the QTH and have no idea if I have enough time to fit in a park or summit activation. Because of this, I always keep a radio field kit in the car.

On Monday, January 31, 2022 I had an appointment-packed day ahead of me, but I was hopeful I might be able to squeeze in a quick activation of some sort.

Specifically, I had a new-to-me super easy, drive-up SOTA site in mind: Peach Knob (W4C/CM-097). In fact, it’s a bit odd that I hadn’t activated this site before. It must be the most accessible summit (to me) in the area.

After a 2:00 appointment in downtown Asheville, I drove 15 minutes to the summit of Peach Knob where I discovered 1.) there was almost no space to park and 2.) what little space there was was taken up with crews working on a cluster of communications towers. In situations like this, the last thing I want to do is get in the way; that sort of activator persistence could lead to “no trespassing” signs in the future.

The site also reminded me that what I love about SOTA is the hike to the summit. Sites like this one are wedged between private property and city property–I just feel like I’m in the way, arousing neighborhood suspicions, and just doing the activation for the points. I’m not a points guy (though I’ll do a happy dance when I accumulate 1000 for ‘Mountain Goat’ status sometime within a decade at this rate).

Moving forward, I think I’ll skip drive up sites like this one; at least for HF activations.

At this point, I pretty much abandoned the idea of a field activation as I’d taken up the wee bit of free time in my schedule just checking out Peach Knob.

Next, I popped by Vlado’s (N3CZ) QTH to drop off some parts so he could finish the repair of my Elecraft KX1.  While chatting with him, I received a message from our grocery store noting that our 4:00 curbside pickup would be delayed. This opened up a one hour window where I could perform an activation! Woo hoo! Continue reading A quick roadside activation with the Elecraft KX2 and CHA MPAS Lite

POTA RaDAR Run Activation #4: A “wham bam” activation at Johns River Game Land

On January 26, 2022, I fit in multiple park activations in one day as a RaDAR (Rapid Deployment Amateur Radio) run. My hope was to activate four or five sites between 14:00 – 21:30 UTC.

Here are the field reports and videos of my first three activations:

The next park in my run (#4) was either going to be my last activation, or second to last depending on my available time.

After visiting with my buddy, Hamilton, at his ceramics studio in Morganton (read about that in the previous report) I looked at the time and decided I could fit in a very quick activation of Johns River Game Land (#4) en route to Tuttle Educational State Forest (#5).

I made up my mind en route that I’d use my fastest-to-deploy combo: the Elecraft KX2 and Chameleon CHA MPAS Lite.

I really wanted to be in and out of the site within a 20 minute window. That’s actually very doable as long as I could rack up at least ten contacts in 10-15 minutes. Some days, propagation can make that a tall order, though!

Johns River Game Land (K-6916)

Johns River actually has a number of access points and, frankly, none of them are exactly “bucolic.” Other than the river itself which is beautiful and the main access point for the river which is well-maintained, most of the game land parking areas are filled with litter.

I chose a parking area for this activation which has, in the past, looked like a dumping ground. I was pleased when I pulled into the parking lot this time to find it much cleaner (no old refrigerators or sofas dumped at the far end of the lot) but then again the snow on the ground was likely hiding quite a bit of litter! My philosophy is to always leave a site cleaner than I found it, but Johns River often has so much littler, I could spend a week picking up trash.

After doing a very short intro for my activation video, I set up the Elecraft KX2 and MPAS Lite antenna in a matter of two minutes.

Gear:

On the air

I started calling CQ POTA (with my fingers crossed!) on 40 meters and was very pleased that chasers were out and about!

I worked my ten contact in 9 minutes and then went QRT! Woot!  Here’s the log sheet:

In this short activation, there was actually a P2P with Max (WG4Z) who was just up the road at Tuttle Educational State Forest. We were definitely working each other via ground wave.

The contacts were flowing so well, that I wanted to stay on the air a bit longer, but I knew to fit in Tuttle and a hike, I really needed keep moving. As soon as I worked my ten, I hopped off the radio.

While I like putting more contacts in the log–especially when they’re flowing so freely–it was actually kind of fun to validate this activation in somewhat of a “sprint.”

QSO Map

Here’s what 5 watts and the MPAS Lite yielded in nine minutes on the air:

Activation video

Here’s my real-time, real-life video of the entire activation. This must be one of the shortest activation videos I’ve ever made:

Click here to view on YouTube.

Thank you

Thank you so much for reading this short report and coming along with me on this RaDAR run! I’ll be posting Park #5–Tuttle Educational State Forest–soon where I catch up with Max (WG4Z) and we work park-to-park once again.

As always, I’d like to send a special thanks to those of you who have been supporting the site and channel through Patreon and the Coffee Fund. While certainly not a requirement as my content will always be free, I truly appreciate the support.

These are crazy times we’re living in these days (at time of posting). I wish all of you good health, safety, and peace–especially our good friends in Ukraine.

Let’s all treat each other with kindness and respect this week as we remember that all we’ve got on this old planet is each other.

I hope you get some time to play radio this week!

72,

Thomas (K4SWL)

Summits On The Air: Pairing the Elecraft KX2 and Chameleon CHA MPAS Lite on Bearwallow Mountain!

So far this winter has been a challenge in terms of activating summits. For me, at least.

Between my busy schedule, family life, and the weather, it’s been difficult to make the stars align. Activating a summit, in general, requires much more time than activating a park. At least, where I live.

Summits tend to be much less accessible and time-consuming than, say, a state or national park. Besides getting to the summit trailhead and hiking it, there can be quite a bit more research in advance including reading previous activator notes and mapping out the true summit location.

SOTA (Summits On The Air) activators (depending on their location) often have extra incentive to do activations during the winter because many of us can accumulate “bonus points” for summits above a certain height during the winter months.

As I’ve mentioned before, I’m not a numbers guy and honestly couldn’t tell you, for example, how many parks I’ve activated this year. But it would be awfully fun to eventually achieve “Mountain Goat” status in the SOTA program. It requires 1000 (!!!) points. Many of the summits where I live range from 1 to 10 points each. Each summit can only count once per year, so if I activate Mount Mitchell (our highest summit) the 10 points only count once in 2022 toward Mountain Goat status. The program is designed to encourage activators to activate a wide variety of unique summits each year. It’s a brilliant motivator.

I will be happy if I achieve Mountain Goat status in 5 years. I simply don’t have the free time to hit summits as often as I’d like. It is a really cool goal though.

Now where was I–? Continue reading Summits On The Air: Pairing the Elecraft KX2 and Chameleon CHA MPAS Lite on Bearwallow Mountain!

Field Report: Pairing the Discovery TX-500, Elecraft T1, and CHA MPAS Lite

You might recall that I’ve been testing a new backpack that I plan to use primarily for SOTA activations. It’s the Spec-Ops Brand T.H.E. Pack EDC.

I’ve now taken it on a few activations, but the very first outing was on Monday, December 7, 2021.

That afternoon, my daughters attended an afternoon art class that was only four miles from our QTH as the crow flies, but took 45+ minutes to drive. Gotta love the mountains!

I had no complaints whatsoever about the drive, though, because it was within five minutes of the Zebulon Vance Historic Birthplace; one of my favorite local POTA spots!

Zebulon B. Vance Birthplace (K-6856)

After dropping off the girls, I drove to Vance and was happy to see that no one was occupying their one picnic shelter. Even though the Vance site is relatively spacious and they’ve numerous trees along the periphery of the property, it’s a historic/archaeological site and as a rule of thumb I only set up at picnic areas in parks like these.

It was a breezy day and temps were hovering around 44F/7C. These are ideal conditions in my world.

I grabbed the Discovery TX-500 for this activation. I had been using it quite a bit in the shack, but realized I hadn’t taken it to the field in a few weeks. I decided to pair it with the Chameleon MPAS Lite vertical antenna since I had already loaded the Lite in my pack, using the pack’s built-in antenna port. Continue reading Field Report: Pairing the Discovery TX-500, Elecraft T1, and CHA MPAS Lite