Tag Archives: Problem Solving

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 →

Antennas, Field Reports, Morse Code, News, Portable, POTA, QRP

POTA with the Icom IC-703 Plus: Working a serious SWR problem first, though!

October 31, 2022 Thomas Witherspoon 25 Comments

If you’ve been here long, you’ve no doubt noticed that I have a sizable collection of QRP radios I take to the field.

Although I have some favorites, I try to rotate all of my radios in the field and even pair them with different antenna combinations as much as possible. If I only owned one field radio, I’d shake things up by pairing my one radio with different antennas deployed different ways during my POTA/SOTA activations.

I get a real thrill out of testing different combinations, actually, and I feel like it keeps me on my toes because I don’t get too comfortable with any one setup in the field.

No doubt, using a wide variety of radios gives me a more informed perspective when beta testing or evaluating new radio models.

That said, there is one radio in my collection that has been overlooked too many times: my Icom IC-703 Plus.

Many of you have noticed this, in fact. I’ve gotten several emails and comments asking, “So Thomas…when are you taking the 703 out again–?” 🙂

When I purchased the ‘703 from my buddy Don a couple years ago, I imagined taking it to the field very regularly. I always thought it was a cool little radio and with its built-in ATU, it’s quite compact for a tabletop-style rig.

Thing is, each time I’ve taken it to the field, I’ve had issues with the electronic keying that I did not have when using it in the shack. It’s quite sensitive to RF, so end-fed antennas seem to create unwanted dits and dashes in the keyer.

The simple fix, I hoped, was simply using an in-line common mode choke to keep the RF away from the radio. Thing is, the IC-703 has an SO-239 antenna port and two of my common mode chokes are BNC. I meant to purchase a BNC-to-PL-259 adapter at the Shelby Hamfest, but picked up the wrong item (I should have been wearing my glasses).

Then I remembered that my Chameleon 50′ RG-58C/U cable not only has an integrated in-line choke, but also PL-259 connectors. This could work! Continue reading POTA with the Icom IC-703 Plus: Working a serious SWR problem first, though! →

Field Reports, Morse Code, News, Portable, POTA, QRP, QRP Radios

POTA in the Dark: Problem solving as the sun sets and the clock is ticking on my UTC day

October 27, 2022 Thomas Witherspoon 9 Comments

Have you ever had an activation that didn’t quite go to plan?

Yeah. Me too.

Truth is, it’s just the nature of field radio that things sometimes break, behave erratically, and/or some key component goes missing. When you’re lugging your gear around in a pack and deploying it outdoors in a wide variety of settings it’s a much less “controlled” environment than, say, in the shack.

When a problem arises, you have to work that problem in the field to get on the air and complete the activation.

If you watch my activation videos, you’ll note that I try to include everything in them–including mistakes and mishaps.

Mishaps that lead to a failed activation happen less frequently than they did when I first got started in the world of field radio. Over the years, I’ve refined my field kit and made sure I’ve got the right spare components and tools to solve minor issues I might encounter.

That said, I felt like my activation attempt of Lake James State Park on Wednesday, October 5, 2022 was a total comedy of errors. It seemed like an extra layer of complication presented itself each step along the way as I tried to activate that park.

Lake James State Park (K-2739)

The plan was to leave my home around 17:15 local, arrive at the park around 18:00, set up my Icom IC-703 Plus, pair it with a 40 meter end-fed half-wave, hop on the air and work stations until about 19:00 (23:00 UTC) at the latest, then pack up and continue driving another hour to my final destination.

Here’s how it actually played out…

I had all of my bags packed and ready to go at 17:15, but as I was ready to leave, I discovered a plumbing leak under our kitchen sink. It required immediate attention (obviously) so I grabbed my tools, pulled everything out from under the kitchen sink, found the leak, and sorted out the issue. Thankfully, I had some spare plumbing parts at the house. This only delayed my departure about 30 minutes.

I arrived at Lake James around 18:30 and had the entire park to myself.

My real goal at the park was to take the Icom IC-703 Plus out for a little fresh air. It had been ages since I put it on the air in the field. The last time I tried to use it in the field, the internal keyer was tripping up due to a little RF coming back to the radio from my end-fed half-wave. This is a known issue with the Icom IC-703–it’s more sensitive to RF than any other radio I own.

This time, I planned to eliminate the RF with the inline common mode choke built into my Chameleon 50′ cable.

I grabbed my throw line, MM0OPX EFHW and had the antenna deployed in record time.

You can’t tell from the photos because my iPhone does a great job with low-light, but the sun was setting quickly even as I set up the IC-703. I knew I’d be finishing the activation in the dark, but I had a headlamp handy so wasn’t concerned (again, never leave home without a headlamp!).

I turned on the ‘703 and the 40 meter band was chock-full of signals. A very good sign!

Then I switched the 703’s meter to the SWR setting and sent a couple of dits on an open frequency to confirm a low SWR.

The SWR was off the charts poor, pegging the SWR meter at 9:1 (or worse?).

What–?

Continue reading POTA in the Dark: Problem solving as the sun sets and the clock is ticking on my UTC day →