Category Archives: QRP Radios

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

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

When one KX1 is not enough. (For me, it seems.)

If you’ve been following this site for long, you’ll know I’m a big fan of the Elecraft KX1 [understatement alert].

I owned one for the better part of a decade, then sold it to purchase a KX2 in 2016. I almost instantly regretted selling it.

In 2020 I purchased another KX1 for $300; like my previous one, it was a four band model, with ATU and paddles. In fact, it even came with a number of other accessories like a proper Pelican 1060 case.

I made dozens of POTA activations with this little KX1 and named her “Ruby” (because I tend to name radios that are a permanent part of my collection).

Trouble in paradise

In the summer of 2021, though, Ruby started exhibiting some issues. This was not completely unexpected because:

  1. All KX1s started life as a kit. None were factory assembled and tested by Elecraft. Quality varies based on the original kit builder.
  2. I believe Ruby is pushing 20 years old.

The main issue was, after turning on the power switch, the rig wouldn’t completely power up. Instead of the typical two clicks we KX1 owners are accustomed to hearing, I only heard one click and neither the display nor any of the functions worked.

This was an intermittent issue–the next day it might power up as it should. I continued operating and tried to find the issue myself, but my skills at doing repairs on radios is very limited.

I took Ruby to Dr. Vlado who traced the issue to a faulty encoder. I purchased a replacement encoder from Elecraft (along with a number of other spares) and Ruby was back on the air!

Back on the air for a while…

A couple months later, I discovered that power output would drop to nearly zero watts after about 20-25 minutes on the air. Basically, when the radio would get warm from operating, power output was affected.

Vlado traced the issue to a cold solder joint and repaired it (while also double checking other joints). Ruby worked perfectly for a few more activations…then once again the same issue with power output dropping reared its ugly head.

Right before we left for Canada this summer, Vlado found yet another cold solder joint and made the repair.

Once we were back home from Canada, I put Ruby back on the air. I did a lot of SOTA/POTA chasing from home and took her on a couple activations.

All was going well until a few weeks ago (you may see this in an upcoming activation video) when once again, power output took a nose dive after the radio warmed up from operating.

It appears old Ruby is just littered with cold solder joints.

I brought her home and decided that I would pull her completely apart this winter and re-solder every point on her board.

Parts radio hunt

Last year, I started hunting for a second KX1. I didn’t care if it was fully functioning because I was mainly searching for a parts radio.

The KX1 has become–and you’ll know this if you’ve been looking for one as well– as rare as hen’s teeth. When they do appear on the market, they command a premium.

In a full year, looking pretty steadily, I only found one reasonable deal on what sounded like a quality KX1. I contacted the seller and he told me that within the one hour his ad was published, he received 10 offers. He asked if I wanted to be put on the waiting list if all ten fell through.

“Okay, I guess?”

I blame the KX1 price increase on a few factors:

  • Elecraft discontinued the KX1 several years ago. No more are being made.
  • Others are looking for spare KX1s.
  • The CW renaissance we’re going through (truly an amazing thing!)
  • The popularity of POTA and SOTA
  • It is still a very unique and capable field radio
  • And quite possibly me, being so public about my love and admiration of the KX1 (where’s that foot of mine so I can shoot it?)

If you’ve been looking for a KX1, you’ve no doubt noticed the low supply and high prices.

Frankly, I’ve even felt a bit guilty looking for a second KX1 knowing how few there were on the market.

Then an opportunity

A few weeks ago, I was chatting with a friend and–long story short–I discovered that a mutual friend of ours would be willing to sell me his KX1.

It was a three band model with ATU and paddles.

He was the original builder and, in fact, this was the third KX1 he’d built. I know him and his soldering work; it’s top-shelf and professional.

I knew I’d likely never get an opportunity to be only the second owner of a KX1 and to actually know that the builder is one of the best out there.

He offered it to me for a fair price based on the current market.  I didn’t want him to lose money by selling to me, so I agreed.

I’ve already taken the new KX1 on three activations and it’s performing flawlessly. In fact, I believe the built-in ATU is even doing a better job finding matches that the one in Ruby.

I still plan to work on Ruby this winter–it’ll make for a nice relaxing project some cold, snowy day. It’s the same process Vlado would have to go through (and he’d do it without hesitation) but I’d rather do it myself and save his time especially since it’ll be a bit tedious.

Oh yeah. The name for my new KX1?

Meet Ingrid!

Thank you for reading this post (which is arguably more of a confession and justification)! As always thank you for your support.

An evening POTA activation with the Penntek TR-45L, a pileup, and buddy Steve

 

Last month, my buddy Steve (VA3FLF/KM4FLF) was in North Carolina visiting family and we hoped to meet up in person at some point.  Thing was, both of our schedules were pretty busy with various family activities and projects.

On Wednesday, September 21, 2022, we found an opening in the evening that coincided with a trip to do a little caregiving for my parents. We agreed to meet up at Lake Jame State Park (K-2739) which was on my way and also convenient to Steve.

Steve is also a fan of Parks On The Air, so why not fit in an activation? No better way to spend time with POTA family than at a POTA park, right? Right!

I arrived at the park around 18:30 local (22:30UTC) and set up MM0OPX’s 40 meter end-fed half-wave.

I only had one radio with me at the time: my prototype Penntek TR-45L.

At that point, the TR-45L had not yet been released and was in the very final stages of Beta testing. I was waiting on one more firmware update to bring the radio up to what would eventually be version 1.

Since I was still waiting on the final update that sorted out the CW message memory recording function (and boy did it–the final version is benchmark) I didn’t use message memories during this outing.

I offered Steve a hand at the TR-45L, but he claimed he wasn’t a heavy CW operator–he was interested in helping me with logging, though. How could I refuse that?

Continue reading An evening POTA activation with the Penntek TR-45L, a pileup, and buddy Steve

Photos of Mike’s uber-organized Icom IC-705 field kit

Many thanks to Mike (2E1BFH) who shares the following photos of a new field kit he’s built around the Icom IC-705:


 


Continue reading Photos of Mike’s uber-organized Icom IC-705 field kit

Ken’s photos comparing five field radios

Many thanks to Ken (WW5A) who writes:

Hello Thomas-

I enjoy reading the posts on the QRPer. The size comparison photos recently posted got me thinking. I had taken a photo several months back of a X5105, 817, RS918 (McHF), G90 and a 705, basically to do the same thing (size comparison).

I have attached them for your amusement [click to enlarge]:

73,

Ken WW5A

Thanks for sharing these, Ken. To me, it’s interesting to see the comparison between the FT-817 and the G90. When I owned a G90 I didn’t have an 817 at the time for comparison. It reminds me just how long/deep that G90 was! Also interesting to see that the mcHF clone is a wee bit wider than the IC-705. Thanks for sharing!

Photos: Comparing sizes of the Mountain Topper MTR-4B, MTR-3B, and Elecraft KX1

After sharing a few photos by request comparing the size of the  Mountain Topper MTR-3B, MTR-4B, and Elecraft KX2 yesterday, I took a few pmore photos by request comparing those same radios with the Elecraft KX1.

I decided to simply post these on QRPer.com in case they could also be of help to someone else:

Mountain Topper MTR-3B v Elecraft KX1

Mountain Topper MTR-4B v Elecraft KX1

Elecraft KX1 v KX2

Photos: Comparing sizes of the Mountain Topper MTR-4B, MTR-3B, and Elecraft KX2

A reader/subscriber just asked for photos comparing the size of the  Mountain Topper MTR-3B and MTR-4B. I know they were also curious how the MTR-4B might compare in size with the Elecraft KX2. Of course, one can look up the actual sizes, but sometimes a photo adds more context.

I decided to simply post these on QRPer.com in case they could also be of help to someone else:

Mountain Topper MTR-4B vs MTR-3B

Mountain Topper MTR-4B vs Elecraft KX2

Why does the Mountain Topper MTR-4B (& 3B) have three separate band switches?

A question I’ve received several times since sharing my last field activation with the MTR-4B is “why do Mountain Topper radios have three individual band switches–?

That’s a great question and the answer is actually in the product manual.

The following comes from the MTR-3B manual but also applies to the MTR-4B (save the 4B has four band positions instead of three):

The band is selected by three, three position slide switches. For proper operation, all three switches must be in the same
column[…]. It’s easy to get into the habit of flipping each switch in sequence from the top down.

The top switch tells the processor which band to operate on and connects the Receiver input filter to the first mixer. The
middle switch connects the transmitter low pass filter output to the antenna and connects the antenna to the receiver
input filter. The bottom switch connects the output of the transmitter PA to the low pass filter.

The manual is correct: it’s easy to get in the habit of sliding all three switches with band changes. It becomes second nature in very short order.

It’s easy to tell that all of the switches are in the correct position as well because without all three switches selected, the receiver sounds deaf and audio muted. With them in position, the receiver sounds “alive.”  (That said, the noise floor is so low on these radios, it’s quite possible you might think they’re not engaged properly if there aren’t many signals on the band!) Of course, it’s very easily to visually inspect the switches and confirm they’re in the correct position.

Side note: On the Mountain Topper series, each band switch is an independent mechanical switch. On the Venus SW-3B (which was no doubt inspired by the Mountain Topper) the two band switches are bound together as one:

You can’t tell from looking at the photo above, but if you slide the top switch, you’re also sliding the bottom switch: the two switches are only one mechanical piece. An interesting design choice!

Side Note: The (now discontinued) Mountain Topper MTR-5B had a more complex series of six switches. Here are the instructions for it along with a drawing from the MTR-5B manual:

I hope this helps clarify how/why the Mountain Topper series uses multiple switches for band changes!

The FX-4L QRP SDR HF transceiver is on order!

This year, I’ve had a couple of readers very kindly offer to loan me their FX-4C transceivers to take to the field and review.

Those offers have been very temping because I’ve only heard positive comments from owners of this wee feature-packed SDR transceiver designed by Yu (BG2FX).

Earlier this year, I learned that Yu was retiring the FX-4C and would be introducing two new radios, so I decided to hold off on an FX-4C review for this reason.

My buddy, Don, informed me that the new radios were now available for pre-order, so I checked out the option on Yu’s website, and placed an order.

Details (features and specs) are still a little sparse because BG2FX is still finalizing the design and lining up production, but here’s a snapshot of the two models based on Yu’s preliminary info:

The FX-4CR

I was very pleased to read that my buddy John (AE5X) has one of these on order.

The FX-4CR can push 15-20 watts on most bands according to John, which is most impressive for a one pound radio that fits in the palm of your hand! It covers 80 – 6 meters, sports a color screen with a 48 kHz wide waterfall display, an internal sound card for digital modes, built-in speaker and microphone, 9 – 18 VDC input range, and even sports Bluetooth!

That’s an impressive array of features for $550 US (on pre-order).

The FX-4L

I pre-ordered the FX-4L and am told by Yu that it should ship by end of October or early November 2022. I wouldn’t be surprised if that’s an optimistic projection.

The FX-4L is essentially a more basic QRP version of the FX-4CR; it’s maximum output power is around 5 watts.

It’s very similar to the FX-4CR in many respects: it has the same display from what I can tell, covers 80 – 6 meters, has a wide voltage range 9 – 18 VDC, sports an internal sound card, and is super compact and lightweight.

The FX-4L doesn’t appear to have Bluetooth. Lu doesn’t mention a built-in speaker or microphone, but there’s an obvious speaker grill and even a small hole that might be a microphone. I’ll try to confirm this. Yu does note that there’s room in the chassis for the user to add a battery or ATU.

I’ve been more interested in the FX-4L because, as you likely know, it’s very rare for me top operate over 5 watts of power.

That said, I certainly see the appeal of a 15W+ radio like the FX-4CR.

(Many thanks to Yu for sharing all of the FX-4L photos above.)

Stay tuned!

I’m really looking forward to checking out the FX-4L and also reading AE5X’s assessment of the FX-4CR.

I’m curious if anyone else has pre-ordered one of these radios. Also, if you’re an FX-4C owner, I’d love to hear your comments!

What are my favorite QRP field radios in terms of audio quality–?

Many thanks to QRPer.com reader, Charles, who recently sent me the following question:

Thomas, I’ve watched a number of your videos and read your activation reports. I’m studying for both my Technician and General class license right now and hope to pass both in one session later this month. I’m also learning CW.

I consider myself an audiophile and appreciate good audio fidelity. I know that amateur radio modes are narrow and by their very nature have less audio fidelity than commercial broadcast modes. 

I’ve already obtained a Kenwood TS-590G for the shack. It was practically given to me by a friend. I’m very pleased with its audio fidelity especially when I connect it to an external speaker.

Next year, I plan to buy a dedicated QRP field radio. Out of the radios you’ve owned, what are your favorites in terms of audio fidelity. Also, what are your least favorites?

Thank you.

What a great question, Charles!

Being an audiophile, I’m sure you understand that this is a very subjective area: one person’s idea of good audio might not match that of someone else’s.

I can only speak to how I evaluate a transceiver’s audio.

What makes for good audio?

A lot goes into what I would call “good audio” in an amateur radio transceiver.

To me, “good audio” means the radio

  • produces clear accurate sound,
  • has stable AGC (Auto Gain Control),
  • has audio properties that benefit amateur radio modes like CW and SSB,
  • has enough audio amplification to be heard in noisy field conditions,
  • and has little to no internally-generated noises leaking into the audio amplification chain. (In other words, a low noise floor.)

In contrast, radios with poor audio

  • sound noisy/harsh,
  • have a high noise floor or produce audio hash making it difficult to hear weak signals,
  • have speakers that become distorted at higher volume levels,
  • have poor AGC characteristics which lead to pumping,
  • and are simply fatiguing to listen to during extended on-air sessions (like long activations or contests).

I would add that a good receiver front end is an important part of audio because it keeps imaging and overloading at bay, thus producing a less cluttered and noisy audio experience.

My field audio favorites

I’ll keep this discussion limited to QRP field portable radios. There are numerous 100 watt desktop radios with excellent audio because those models aren’t trying to limit their current consumption like field radios typically do. They can use more amperage to benefit audio amplification and push a much larger speaker.

In addition, I’ll limit the scope to field radios with built-in speakers. There are some great CW-only radios out there that lack an internal speaker but have great audio (thinking of the Penntek TR-35 and the Elecraft KX1, for example); choice of earphones or headphones can have a dramatic effect on audio. That’s a different discussion altogether!

Best audio: My top three picks

The following are three of my favorite portable field radios in terms of audio quality. I limited myself to three simply because all of the radios I use regularly in the field have what I would consider good and acceptable audio.

The following are simply stand-outs, in my opinion:

Continue reading What are my favorite QRP field radios in terms of audio quality–?