Category Archives: QRP

Elecraft KX1: Back with my portable radio companion

The Elecraft KX1

Note: This article was first published on QRPer.com.

A few weeks ago, I published a post about radios I’ve regretted selling or giving away.

Number one on that list was the Elecraft KX1.

Within a couple hours of posting that article, I had already purchased a KX1 I found on the QTH.com classifieds. It was, by any definition, an impulse purchase.

The seller, who lives about 2 hours from my QTH, described his KX1 as the full package: a complete 3 band (40/30/20M) KX1 with all of the items needed to get on the air (save batteries) in a Pelican 1060 Micro Case.

The KX1 I owned in the past was a four bander (80/40/30/20M) and I already double checked to make sure Elecraft still had a few of their 80/30 module kits available (they do!).  I do operate 80M in the field on occasion, but I really wanted the 80/30 module to get full use of the expanded HF receiver range which allows me to zero-beat broadcast stations and do a little SWLing while in the field.

The seller shipped the radio that same afternoon and I purchased it for $300 (plus shipping) based purely on his good word.

The KX1 package

I’ll admit, I was a bit nervous: I hadn’t asked all of the typical questions about dents/dings, if it smelled of cigarette smoke, and hadn’t even asked for photos. I just had a feeling it would all be good (but please, never follow my example here–I was drunk with excitement).

Here’s the photo I took after removing the Pelican case from the shipping box and opening it for the first time:

My jaw dropped.

The seller was right: everything I needed (and more!) was in the Pelican case with the KX1. Not only that, everything was labeled. An indication that the previous owner took pride in this little radio.

I don’t think the seller actually put this kit together. He bought it this way two years ago and I don’t think he ever even put it on the air based on his note to me. He sold the KX1 because he wasn’t using it.

I don’t know who the original owner was, but they did a fabulous job not only putting this field kit together, but also soldering/building the KX1. I hope the original owner reads this article sometime and steps forward.

You might note in the photo that there’s even a quick reference sheet, Morse Code reference sheet and QRP calling frequencies list attached to the Pelican’s lid inside. How clever!

I plan to replace the Morse Code sheet with a list of POTA and SOTA park/summit references and re-print the QRP calling frequencies sheet. But other than that, I’m leaving it all as-is. This might be the only time I’ve ever purchased a “package” transceiver and not modified it in some significant way.

Speaking of modifying: that 80/30 meter module? Glad I didn’t purchase one.

After putting the KX1 on a dummy load, I checked each band for output power. Band changes are made on the KX1 by pressing the “Band” button which cycles through the bands one-way. It started on 40 meters, then on to 30 meters, and 20 meters. All tested fine. Then I pressed the band button to return to 40 meters and the KX1 dived down to the 80 meter band!

Turns out, this is a four band KX1! Woo hoo! That saved me from having to purchase the $90 30/80M kit (although admittedly, I was looking forward to building it).

Photos

The only issue with the KX1 was that its paddles would only send “dit dah” from either side. I was able to fix this, though, by disassembling the paddles and fixing a short.

Although I’m currently in the process of testing the Icom IC-705, I’ve taken the KX1 along on a number of my park adventures and switched it out during band changes.

Indeed, my first two contacts were made using some nearly-depleted AA rechargeables on 30 meters: I worked a station in Iowa and one in Kansas with perhaps 1.5 watts of output power–not bad from North Carolina!

I’m super pleased to have the KX1 back in my field radio arsenal.

I name radios I plan to keep for the long-haul, so I dubbed this little KX1 “Ruby” after one of my favorite actresses, Barbara Stanwyck.

Look for Ruby and me on the air at a park or summit near you!

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Icom IC-705 blind audio tests: Let’s take a look at your choices!

Before I had even taken delivery of the new Icom IC-705 transceiver, a number of SWLing Post readers asked me to do a series of blind audio comparison tests like I’ve done in the past (click here for an example).

Last week, I published a series of five audio tests/surveys and asked for your vote and comments. The survey response far exceeded anything I would have anticipated.

We received a total of 931 survey entries/votes which only highlights how much you enjoy this sort of receiver test.

In this challenge, I didn’t even give you the luxury of knowing the other radios I used in each comparison, so let’s take a look…

The competition

Since the Icom IC-705 is essentially a tabletop SDR, I compared it with a couple dedicated PC-connected SDRs.

WinRadio Excalibur SDR

The WinRadio Excalibur

I consider the WinRadio Excalibur to be a benchmark sub $1000 HF, mediumwave, and longwave SDR.

It is still my staple receiver for making off-air audio and spectrum recordings, and is always hooked up to an antenna and ready to record.

In the tests where I employed the WinRadio Excalibur, I used its proprietary SDR application to directly make recordings. I used none of its advanced filters, AGC control, or synchronous detection.

Click here to read my original 2012 review of the WinRadio Excalibur.

Airspy HF+ SDR

The Airspy HF+ SDR

I also consider the Airspy HF+ SDR to be one of the finest sub-$200 HF SDRs on the market.

The HF+ is a choice SDR for DXing. Mine has not been modified in any way to increase its performance or sensitivity.

In the test where I employed the HF+ I used Airspy’s own SDR application, SDR#, to directly make recordings. I used none of its advanced filters, AGC control, noise reduction, or synchronous detection.

Belka-DSP portable receiver

The Belka-DSP

I recently acquired a Belka-DSP portable after reading 13dka’s superb review.

I thought it might be fun to include it in a comparison although, in truth, it’s hardly fair to compare a $160 receiver with a $1300 SDR transceiver.

The Belka, to me, is like a Lowe HF-150 in a tiny, pocket package.

Elecraft KX3 QRP transceiver

The Elecraft KX3

The KX3 is one of the best transceivers I’ve ever owned. Mine has the CW roofing filter installed (only recently) and is, without a doubt, a benchmark performer.

Click here to read my full review.

If you check out Rob Sherwood’s receiver test data table which is sorted by third-order dynamic range narrow spaced, you’ll see that the KX3 is one of the top performers on the list even when compared with radios many times its price. Due to my recording limitations (see below) the KX3 was the only other transceiver used in this comparison.

Herein lies a HUGE caveat:

The WinRadio application

As I’ve stated in SDR reviews in the past, it is incredibly difficult comparing anything with PC-connected SDRs because they can be configured on such a granular level.

When making a blind audio test with a stand-alone SDR radio like the IC-705–which has less configurability–you’re forced to take one of at least two paths:

  • Tweak the PC-connected SDR until you believe you’ve found the best possible reception audio scenario and use that configuration as a point of comparison, or
  • Attempt to keep the configuration as basic as possible, setting filters widths, AGC to be comparable and turning off all other optional enhancements (like synchronous detection, noise reduction, and advanced audio filtering to name a few).

I chose the latter path in this comparison which essentially undermines our PC-connected SDRs. Although flawed, I chose this approach to keep the comparison as simple as possible.

While the IC-705 has way more filter and audio adjustments than legacy transceivers, it only has a tiny fraction of those available to PC-connected SDRs. Indeed, the HF+ SDR, for example, can actually be used by multiple SDR applications, all with their own DSP and feature sets.

In short: don’t be fooled into thinking this is an apples-to-apples comparison. It is, at best, a decent attempt at giving future IC-705 owners a chance to hear how it compares in real-word live signals.

Recordings

The Zoom H2N connected to my Elecraft KX2.

Another limiting factor is that I only have one stand-alone digital audio recorder: the Zoom H2N. [Although inspired by Matt’s multi-track comparison reviews, I plan to upgrade my gear soon.]

The IC-705 has built-in digital audio recording and this is what I used in each test.

The WinRadio Excalibur and Airspy HF+ also have native audio recording via their PC-based applications.

With only one stand-alone recorder, I wasn’t able to simultaneously compare the IC-705 with more than one other stand-alone receiver/transceiver at a time.

As I mentioned in each test, the audio levels were not consistent and required the listener to adjust their volume control. Since the IC-705, Excalibur, and HF+ all have native recording features, the audio levels were set by their software. I didn’t post-process them.

Blind Audio Survey Results

With all of those caveats and disclaimers out of the way, let’s take a look at the survey results.

Blind audio test #1: 40 meters SSB

In this first test we listened to the IC-705, WinRadio Excalibur, and Belka-DSP tuned to a weak 40 meter station in lower sideband (LSB) mode. Specifically, this was ham radio operator W3JPH activating Shikellamy State Park in Pennsylvania for the Parks On The Air program. I chose this test because it included a weak station calling CQ and both weak and strong stations replying. There are also adjacent signals which (in some recordings) bleed over into the audio.

Radio A: The Belka-DSP

Radio B: The WinRadio Excalibur

Radio C: The Icom IC-705

Survey Results

The Icom IC-705 was the clear choice here.

Based on your comments, those who chose the IC-705 felt that the weak signal audio was more intelligible and that signals “popped out” a bit more. Many noted, however, that the audio sounded “tinny.”

A number of you felt it was a toss-up between The IC-705 and the Belka-DSP. And those who chose the WinRadio Excalibur were adamant that is was the best choice.

The WinRadio audio was popping in the recording, but it was how the application recorded it natively, so I didn’t attempt to change it.

Test #2: 40 meters CW

Icom IC-705In this second test we listened to the Icom IC-705 and the Elecraft KX3 tuned to a 40 meter CW station.

Radio A: Icom IC-705

Radio B: Elecraft KX3

Survey Results

The Elecraft KX3 was preferred by more than half of you.

Based on your comments, those who chose the KX3 felt the audio was clearer and signals had more “punch.” They felt the audio was easier on the ears as well, thus ideal for long contests.

Those who chose the IC-705, though, preferred the narrower sounding audio and felt the KX3 was too bass heavy.

Test #3: Shannon Volmet SSB

In this third test we listened to the Icom IC-705 and WinRadio Excalibur, tuned to Shannon Volmet on 8,957 kHz.

Radio A: WinRadio Excalibur

Radio B: Icom IC-705

Survey

The Icom-705 audio was preferred by a healthy margin. I believe, again, this was influenced by the audio pops heard in the WinRadio recording (based on your comments).

The IC-705 audio was very pleasant and smooth according to respondents and they felt the signal-to-noise ratio was better.

However, a number of comments noted that the female voice in the recording was actually stronger on the WinRadio Excalibur and more intelligible during moments of fading.

Test #4: Voice of Greece 9,420 kHz

In this fourth test we listen to the Icom IC-705, and the WinRadio Excalibur again, tuned to the Voice of Greece on 9,420 kHz.

Radio A: Icom IC-705

Radio B: WinRadio Excalibur

Survey

While the preference was for the IC-705’s audio (Radio A), this test was very interesting because those who chose the Excalibur had quite a strong preference for it, saying that it would be the best for DXing and had a more stable AGC response. In the end, 62.6% of 131 people felt the IC-705’s audio had slightly less background noise.

Test #5: Radio Exterior de España 9,690 kHz

In this fifth test we listened to the Icom IC-705, and AirSpy HF+, tuned to Radio Exterior de España on 9,690 kHz. I picked REE, in this case, because it is a blowtorch station and I could take advantage of the IC-705’s maximum AM filter width of 10 kHz.

Radio A: Icom IC-705

Radio B: Airspy HF+

Survey

The IC-705 was preferred by 79% of you in this test.

Again, very interesting comments, though. Those who preferred the IC-705 felt the audio simply sounded better and had “punch.” Those who preferred B felt it was more sensitive and could hear more nuances in the broadcaster voices.

So what’s the point of these blind audio tests?

Notice I never called any radio a “winner.”

The test here is flawed in that audio levels and EQ aren’t the same, the settings aren’t identical, and even the filters have slightly different shapes and characteristics.

In other words, these aren’t lab conditions.

I felt the most accurate comparison, in terms of performance, was the 40M CW test with the KX3 because both employed similar narrow filters and both, being QRP transceivers, are truly designed to perform well here.

I essentially crippled the WinRadio Excalibur and Airspy HF+ by turning off all all but the most basic filter and AGC settings. If I tweaked both of those SDRs for optimal performance and signal intelligibility, I’m positive they would have been the preferred choices (indeed, I might just do another blind audio test to prove my point here).

With that said, I think we can agree that the IC-705 has brilliant audio characteristics.

I’ve noticed this in the field as well. I’m incredibly pleased with the IC-705’s performance and versatility. I’ll be very interested to see how it soon rates among the other transceivers in Rob Sherwood’s test data.

The IC-705 can actually be tailored much further by adjusting filter shapes/skirts, employing twin passband tuning and even using its noise reduction feature.

If anything, my hope is that these blind audio tests give those who are considering the Icom IC-705 a good idea of how its audio and receiver performs in real-word listening conditions.


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Taking the Icom IC-705 to the field for a battery endurance test

I recently posted results from my listening endurance test with the new Icom IC-705 QRP general coverage transceiver. I’ve been on a mission to see just how long the supplied BP-272 Li-ion battery pack can hold up with a full charge in real-world conditions.

Thursday, I took the IC-705 to the field and activated a park using only the charged battery pack. After nearly 2 hours of constant operation (calling CQ and working stations) the BP-272 still had nearly 40% of its capacity.

That’s better than I expected, especially knowing the BP-272 is the slim, lower capacity battery pack.

I have to admit: that was a particularly fun activation because propagation finally gave me a break and I worked stations from the Azores to Oregon on a mere five watts of power.

Click here to read my full field report at QRPer.com.

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Icom IC-705: Let’s see how long it’ll receive with supplied BP-272 Li-ion battery pack

The shortwave radio listener part of me might actually be more excited about the Icom IC-705 than the ham radio operator part of me.

The IC-705 has a number of features for ham radio operators who also enjoy broadcast listening. For example, it sports:

  • a general coverage receiver,
  • good performance specs,
  • notch filtering (both manual and automatic),
  • Icom twin passband filtering,
  • an AM bandwidth filter maximum width of 10 kHz
  • built-in digital recording of both received and transmitted audio,
  • audio treble/bass adjustments,
  • and battery power from Icom HT Li-ion battery packs

The Icom IC-705 ships with an BP-272 Li-ion battery pack and since the announcement last year about the IC-705, I’ve been curious how long the BP-272 could power the IC-705 in receive only.

A real-world RX test

Yesterday morning, I resisted the urge to hunt POTA and SOTA stations with the IC-705 and, instead, spent the day simply listening.

I started the experiment with a fully-charged BP-272 7.4V 1880 mAh battery pack (the pack supplied with the IC-705). At 9:00 in the morning, I unplugged the IC-705 from my 12V power supply and ran the receiver all day on just the battery pack.

I made some practical changes to maximize play time: I turned on the screen saver, turned off GPS, set the LCD backlight auto adjustment to 2%, and set the screen timer to turn off after 1 minute.

I ran the volume somewhere between low and moderate and only raised it to what I would consider very loud a few times to copy weak signals. I listened to AM, SSB, and FM signals across the spectrum, but primarily cruised the HF bands.

Of course, I never transmitted with the IC-705 during this period (saving that for the next test).

I probably could have done more to decrease current drain, but frankly I wanted this to be based on how I’d likely configure the rig for use on an SWL DXpedition.

Results

I unplugged the IC-705 from the 12V power supply at 9:00 local and the radio auto shut down at 16:39 local: a total of 7 hours, 39 minutes.

Honestly? I’m fairly impressed with this number mainly because it’s based on the smaller battery pack. The supplied BP-272 pack has 1880 mAh of capacity. The optional BP-307, on the other hand, has 3150 mAh of capacity.

If I decide to keep the IC-705, I will be very tempted to purchase a ($130 US) BP-307 pack as well.

Next test: How long can the IC-705 last on battery during a POTA activation?

As early as today, I will see just how long the BP-272 pack can operate the IC-705 during a POTA activation. This will be a true challenge on the smaller battery pack since POTA activations require a lot of transmitting (constant CQ calls and exchanges). There’ll be no lack of calling CQ on a day like today when propagation is so incredible poor.

Follow the tag IC-705 for more updates.

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The Icom IC-705 has landed at SWLing Post HQ

Yesterday, I received my new Icom IC-705 QRP transceiver (along with two FT-60R HTs) from Universal Radio.

I got home pretty late yesterday afternoon so haven’t had a lot of time to put the IC-705 on the air.

I did tune to the Voice of Greece and REE last night and, must say, was pretty impressed with AM mode.

This morning, I also worked two CW stations and one in SSB on the 40 meter band from my home.

Very early days, but I get the impression the IC-705 receiver is top shelf. At least, I like what I’m hearing.

So far, the only negative I’ve mentally noted is the difficulty in propping up this radio for use on a desk. It’s a little awkward. No doubt, a number of 3rd party solutions will soon emerge. I’m personally hoping someone will design a 3D printed stand/cradle.

Indeed, a 3D-printed front panel cover would also be nice because I do worry about the touch screen display being damaged in my backpack. Being a bit of a picky backpack geek, I did not opt for the custom Icom LC-192 backpack (completely subjective: just not my style and not waterproof). The IC-705 can be secured in the LC-192 so that the front panel is well-protected.

The IC-705 backlit display is very easy on the eyes–I hope it’s as easy to read in sunlight outdoors. We’ll soon find out because I’m certainly taking it to the field!

IC-705 Unboxing Photos

By request, here are some “unboxing” photos (click to enlarge):

Follow the tag IC-705 for more updates.


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My Icom IC-705 is inbound…sharing my predictions

I was contacted by Universal Radio yesterday afternoon with  a tracking number for my Icom IC-705. It will arrive by Monday evening.

A number of SWLing Post readers in the US and UK have notified me that their IC-705s have also been shipped and a few have even been received already.

I’m really looking forward to checking out the IC-705. The preliminary reviews (overviews, really) have been pretty positive. I found the IC-7300 to be a fabulous rig and the IC-705 smacks of the ‘7300. The ‘705 even includes more features than the ‘7300 (multi-mode VHF/UHF, D-Star, Wifi, and built-in GPS to name a few) although lacks an internal tuner.

I’ve received more questions about IC-705 and the TX-500 than I have any other radios this year. Both, in many senses, are ground-breaking in their features, (and in the case of the TX-500) form-factor and build.

If I’m being honest, I was more excited about the TX-500 because it simply suits my field operating style better (my full TX-500 review will be in the Oct 2020 issue of TSM).

Since I haven’t received the IC-705 yet and haven’t read any truly detailed reviews or comparisons, I’m going to do something I’ve never done before and share a few of my personal predictions.

Predictions

I’m human and can’t help but form a few expectations/opinions prior to a thorough rig evaluation. That and, having owned a number of their products, I’m very familiar with Icom as a company. I’ll probably regret this later, but here goes…

I suspect:

  • I’ll like the touch screen display more than I think I will. I’m not a big fan of color backlit displays in field radios. I prefer simple high-contrast LCD displays that are readable in full sunlight. I’m hoping Icom will have optimized the IC-705 display for reading outdoors.
  • I’ll be able to operate the radio without referring to the manual because I’m so familiar with the IC-7300.
  • I’ll really miss having a built-in ATU on a rig in this price class. Feels like a missed opportunity, however seeing the inside of the IC-705, there really isn’t a lot of spare room. With that said, I plan to review the mAT-705 ATU compact external tuner and hope it’ll pair nicely.
  • I’ll be disappointed with the amount of run time I’ll get from a fully-charged BP-272 battery pack. I really hope I’m wrong about this one. Icom did some serious engineering on the IC-705 to lower the amount of current needed in receive. We’ll see if that paid off and if it can compare, for example, to the run time I get from the rechargeable battery pack in my Elecraft KX2.
  • I’ll be very pleased with some of its features like CW and Voice memory keying for POTA and SOTA activations.
  • I’ll still find D-Star complicated to use even though, hypothetically, the IC-705 can connect directly to D-Star via WiFi. I hope I stand corrected on this point.
  • I’ll struggle to find the perfect padded pack to house the radio. I’m a bit of a pack geek/snob and don’t really like the Icom LC-192 backpack. I’ve no intention to order it even though it’s designed to work with the radio. So while this doesn’t apply to 99% of my readers, it’s a big deal in my world. 🙂 I’m sure I’ll sort out a solution.
  • I’ll feel some buyer’s remorse when, in 6 months, the IC-705 price drops a couple hundred dollars. That’s okay. I see it as taking a bullet for my readers (and, let’s face it, I love new radio gear). Plus, I’m banking on the notion that the IC-705 will make for a capable QRP EME transceiver.
  • I’ll love the built-in digital recorder for making off-air shortwave broadcast recordings (although I do fear I’ll find the AM audio filter too narrow).

Again, these are completely off-the-top-of-my-head predictions and based on no hands-on time with th IC-705. Next week, I’ll start to see how many of these predictions are correct and how many I totally missed.

I can tell you this: I’m not sure I want to see the invoice from Universal Radio. It includes the IC-705, two Yaesu FT-60R HTs, and some Anderson PowerPole connectors! Although I’ve had the IC-705 on order for ages, I added the HTs and connectors at the last moment because they don’t seem very pricey when you’re already at the $1300 US mark, right–? (Shhhh! The FT-60Rs are a gift for my daughters who take their Technician test this weekend!)

How about you? Do you have an IC-705 on order? What are your predictions and thoughts? Please comment!

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A 3D-printed cover for the Mountain Topper MTR-3B QRP transceiver

Many thanks to SWLing Post contributor, Eric McFadden (WD8RIF), who asks:

Thomas, what’s the orange thing on the MTR-3B in the last photo in your post about the Red Oxx Booty Boss? [see photo above]

Glad you asked, Eric! It’s a 3D-printed protective cover.

My daughters have been asking for a 3D printer since they’ve used them at Maker Faires, the Pisgah Astronomical Research Institute, and most recently the Huntsville Hamfest. Both of my girls love designing and creating things, so this year we got them one for their birthday.

After loads of research, I purchased a Creality Ender 3 Pro 3D from Amazon.com (affiliate link) for about $240 US. My daughters were thrilled when they unwrapped the box on their birthday to find a 3D printer inside! We spent the following morning assembling it, calibrating the print bed, and printing a sample file.

Like most, our first prints were fun, simple things we found on Thingiverse.  The girls printed a Saturn V rocket, a cat, and an X-Wing fighter. Those prints gave us an opportunity to learn about slicing 3D files, building support structure, and proper bed calibration.

Covering the MTR-3B

When the printer arrived, I already had the Red Oxx Booty Boss on order and was assembling my field radio kit.

One concern I had about the MTR-3B (in any pack) was that the small band switches could catch on a zipper or pocket mesh and be damaged. I had read a few accounts of this happening to others.

The LnR Precision MTR-3B transceiver

I thought about keeping the MTR-3B in a thick poly bag, but I knew that wouldn’t offer a lot of protection for the switches. Out of curiosity, I searched Thingiverse hoping perhaps someone had designed a small case that could possibly house the MTR-3B.

To my surprise, I discovered an engineer actually designed a snap-on cover for the MTR series of radios. It was then a simple matter of downloading the file, slicing it, and setting it to print while I slept that night.

The next morning, I had a cover sitting on the printer bed.

I purchased a pack of multi-color PLA filament knowing it would give my girls an opportunity to play with color a bit. The printer was already loaded with bright orange filament which I thought would be brilliant for the MTR-3B.

Those of you familiar with 3D printing are probably aware that ABS would be a better, stronger material for the cover since the side clips are certainly the weak points of the structure. We haven’t ordered ABS filament yet, but I think the PLA will actually function well for a while–it’s sturdier than I anticipated. When we have ABS in the house, I’ll plan to re-print it.

I couldn’t be more pleased because the cover fits the MTR-3B like a glove and doesn’t add a lot of bulk to this pocket-size transceiver. It was also a great print for beginners.

And best of all, I know the front switches and buttons are well-protected in my field bag.

I’d like to thank Thingiverse designer CockpitBob for designing this little cover and sharing it!

We’re also super pleased with the Creality Ender 3 Pro 3D printer. Thanks to my friends who helped guide that purchase decision.

Care to share?

3D printers are incredibly useful tools for radio enthusiasts of all stripes. I’m still very new to this world, so I would love to hear about your 3D-printed radio projects. Besides this post, we’ve featured at least one in the past, but I’d love to share more.

Please comment or contact me if you’d like us to feature your 3D project!


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