Tag Archives: Matt Blaze

Matt’s 2022 Portable Loop Antenna Shootout

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Many thanks to SWLing Post contributor, Matt Blaze, for the following guest post:

Matt’s 2022 Portable Loop Antenna Shootout

by Matt Blaze, WB2SRI

Followers of this blog may be familiar with my “shortwave radio shootouts” that I post from time to time. The idea is to compare how well different radios demodulate the exact same signal. Basically, I take a bunch of radios, hook them up to the same antenna via an RF distribution amplifier, tune the radios to some distant signal, and record the audio output from them simultaneously. Sometimes that kind of comparison can be more revealing of actual real-world performance than lab measurements or technical specifications.

The other day, I decided to do the same thing, but for antennas instead of radios. Essentially, I inverted the setup. Instead of hooking up different radios to the same antenna, I hooked up identical radios to different portable antennas and recorded them demodulating the same signals at the same time.

In this first of perhaps a series of these antenna shootouts, I wanted to compare three portable amplified magnetic loop antennas. When I say “portable” here, I mean broadband antennas that can pack reasonable compactly for travel and that can be set up and broken down easily for use “on location”, say on a picnic table or hotel balcony, or perhaps installed temporarily on a roof, without too much fuss.

The antennas are:

– The Wellbrook FLX1530LN with a 1 meter diameter loop of LMR400 coax. This is my “standard” portable antenna (I use a telescoping broom handle for the support; I wrote about it here as the “signal sweeper” last year). Excellent performance, but on the bulky side for travel. Performs well from LW through HF. Not cheap, at about USD 225 including shipping for the amplifier and power injector, but not including the loop, mounting hardware, or feedline.

– The Wellbrook FLX1530LN with a 0.5 meter diameter loop of RG142 (a stiff “aircraft grade” version of RG58 that holds it shape well at this size). I used some 1/2 inch PVC pipe as the vertical support. Because of the smaller diameter loop and thinner coax, it packs down to a much smaller and lighter package than the 1 meter LMR400 version.

– The K-180WLA, an inexpensive (about USD 60) 0.5 meter loop from China, sold on eBay and Amazon. The loop is steel wire (which can be wound down to a small diameter for transport), and the kit includes everything you need, including a rechargeable power injector. (However, the power injector uses a noisy voltage booster, so I substituted my own bias-T injector for these experiments). Ostensibly covers LW through VHF, but the low end coverage is, shall we say, somewhat aspirational, as you will see.

– I also recorded, for comparison, the built-in ferrite bar (for LW/MW) and whip antenna (for HF) of the receiver.

This is, of course, only a small sampling of portable loop antennas, both commercial and homebrew. But I wanted to start with what I had on hand and with what meets my own needs. (I omitted from consideration loops that require tuning, since I want to be able to install the antenna without needing access to it every time I change frequency).

For each signal captured, I oriented and positioned each antennas to maximize signal quality, taking care to move them away from each other and interfering metal objects. So you’re hearing (approximately) the best each antenna had to offer (on my roof under suboptimal band conditions).

The receivers I used were four Sangean ATS-909×2 portable LW/MW/SW/FM/Air radios. I believe this to be the best currently available (relatively inexpensive) portable shortwave receiver on the market. It has excellent performance (and is admirably resistant to overload and intermod when used with an active antenna). It lacks a sync mode, but that’s rarely implemented well on portable radios anyway. As a practical matter, it has a good line-level output jack, and I already happened to own four of them.

As in my other shootouts, for each signal, there are a total of five recordings: a monoaural recording of the audio from each of the four antennas, plus a narrated stereo recording comparing a reference (the 1M Wellbrook) on the Left channel with each of the other antennas in succession on the Right channel. The stereo recording is intended as a quick overview, but it will only make sense if you listen in stereo, preferably with good headphones. (You can switch the earcups to get a quick comparison as you listen.)

Continue reading →

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Matt’s Rooftop Receiver Shootout: Round Two!

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Many thanks to SWLing Post contributor, Matt Blaze, for the following guest post:

Matt’s Rooftop Receiver Shootout, Round Two.

by Matt Blaze

You may recall that back in April, I dragged eight of my favorite receivers up to the roof, hooked them up to a portable antenna, and compared their abilities to demodulate various signals at the same time. For the most part, the similarities between radios were more striking than their differences. I hinted that there’d be a second installment to come, including more receivers and more challenging signals, to further expose and highlight the practical real-world performance differences between the radios we use.

So, as promised, here we are with Round Two of my Rooftop Receiver Shootout.

This time around, I used approximately the same setup, but with a total of fifteen different radios. And once again, I took advantage of nice weather and brought a multitude of receivers, recording gear, cables, and an antenna up to my roof to listen to and record shortwave signals under the open sky.

Our fifteen receivers included everything from “dream radios” from the 1980’s to current-production desktop models to less expensive modern portables to high-performance bench-top lab measurement gear. I tried to curate samples of a wide range of radios you may be familiar with as well as some you probably aren’t.

The lineup consisted of:

  • Icom R-8600, a current production “DC to Daylight” (or up to 3 GHz, at least) general coverage communications receiver, with highly regarded shortwave performance.
  • AOR AR-ONE, another DC to 3 GHz general coverage radio, less well known due to the high price and limited US availability. Excellent performer, but a counterintuitive and awkward (menu-driven) user interface is less than ideal for shortwave, in my opinion.
  • Reuter RDR Pocket, a very cute, if virtually impossible to get in the US, small production, high performance SDR-based shortwave portable receiver. It’s got an excellent spectrum display and packs near desktop performance into a surprisingly small package.
  • AOR 7030Plus, an extremely well regarded mobile/desktop HF receiver from the late 90’s. Digital but retaining some important analog-era features like mechanical filters. Designed and (mostly) built in the UK, it’s got a quirky menu-driven user interface but is a lot of fun once you get used to it.
  • Drake R8B, the last of the much-beloved Drake receivers. Probably the chief competitor to the 7030+.
  • Drake R7A, an excellent analog communications receiver (but with a digital VFO) from the early 80’s. It still outperforms even many current radios.
  • Sony ICF-6800W, a top of the line “boom box”-style consumer receiver from the early 80’s. Great radio, but hard to use on SSB, as we saw in Round One.
  • Panasonic RF-4900, the main competition for the Sony. Boat-anchor form factor, but (improbably) can run on internal D-cell batteries. Generally impressive performer on AM, but, like the Sony 6800, difficult to tune on SSB.

You may remember the above radios from Round One back in April. The new radios this time were:

  • Tecsun 501x, a larger-format LW/MW/HF/FM portable released last year. As noted below, it’s a generally good performer, but regrettably susceptible to intermod when connected to a wideband external antenna (as we’ll see in Part One).
  • Tecsun PL-990x, a small-format portable (updating the PL880), with many of the same features as the 501x. Like the H501x, good performance as a stand-alone radio, but disappointing susceptibility to intermod when fed with an external antenna.
  • Sangean ATS-909x, a recent LW/MW/HF/FM portable with a good reputation as well as a few quirks, such as only relatively narrow IF bandwidth choices on HF. Excellent performance on an external antenna.
  • Sangean ATS-909×2, an updated, current production version of the ATS-909x that adds air band and a few performance improvements. Overall excellent, though I would prefer an addition wider IF bandwidth choice. My go-to travel receiver if I don’t want to take the Reuter Pocket.
  • Sony ICF-7600GR, a small-format digital LW/MW/SW/FM portable introduced in 2001 and the last of the Sony shortwave receivers. Showing its age, but still competitive in performance.
  • Belka DX, the smallest radio in our lineup, made in Belarus. You’ll either love or hate the minimalist interface (one knob and four buttons). If you’re going to secretly copy numbers stations in your covert spy lair, this is a good radio to use. Can be difficult to obtain right now due to sanctions.
  • Finally, a bit of a ringer: the Narda Signal Shark 3310, a high performance SDR-based 8.5 GHz RF spectrum and signal analyzer. As with most test equipment like this, demodulation (especially of HF modes) is a bit of an afterthought. But it has an excellent front end and dynamic range, intended for identifying, extracting, and analyzing weak signals even in the presence of strong interference. Not cheap, but it’s intended as measurement-grade lab equipment, not consumer gear. Demodulated audio is noticeably delayed (several hundred ms) compared with other receivers due to the multi-stage DSP signal path.


The antenna was my portable “signal sweeper” Wellbrook FLX-1530 on a rotatable tripod, using a power splitter and a pair of Stridsberg Engineering 8-port HF distribution amplifiers to feed the fifteen radios. So every radio was getting pretty close to exactly the same signal at its RF input. Continue reading →

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Matt’s 2022 Rooftop Receiver Shootout!

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Many thanks to SWLing Post contributor, Matt Blaze, for the following guest post:

2022 rooftop receiver shootout

by Matt Blaze

I realized it’s been long past time for me to do another head-to-head receiver comparison “shootout”, where you can compare the audio from multiple radios receiving the same signal at the same time. Long time readers of Thomas’ blog may remember I’ve posted a few of these before.

So I took advantage of the nice weather and brought a bunch of radios, recording gear, and an antenna up to the roof to listen and record signals under an open sky. My neighbors, no doubt, wondered what I must have been up to. (Don’t tell them I’m just a harmless radio nerd.)

This year, our focus is on eight “dream receivers” from the 1980’s to the present. Each radio is at or near the top of the line in its class at the time of its release. Our radios include, in roughly reverse chronological order:

  • Icom R-8600, a current production “DC to Daylight” (or up to 3 GHz, at least) general coverage communications receiver, with highly regarded shortwave performance.
  • AOR AR-ONE, another DC to Daylight general coverage radio, less well known due to the high price and limited US availability. Excellent performer, but a terrible (menu-driven) user interface for shortwave, in my opinion.
  • Reuter RDR Pocket, a very cute, if virtually impossible to get in the US, small production, high performance SDR-based shortwave portable receiver. It’s got an excellent spectrum display and packs a lot of performance into a surprisingly small package.
  • AOR 7030Plus, an extremely well regarded shortwave receiver from the late 90’s; designed in the UK. It’s got a quirky menu-driven user interface but is a lot of fun to use.
  • Drake R8B, the last of the much-beloved Drake receivers. Probably the chief competitor to the 7030.
  • Drake R7A, an excellent analog communications receiver (but with a digital VFO) from the early 80’s. It still outperforms even many current radios.
  • Sony ICF-6800W, a top of the line “boom box” style consumer receiver from the early 80’s. Great radio, but hard to use on SSB.
  • Panasonic RF-4900, the main competition for the Sony. Boat-anchor form factor, but runs on batteries. Excellent performer, but also hard to use on SSB.

The radios were fed from my portable Wellbrook FLX-1530 antenna, using a Stridsberg Engineering HF distribution amplifier. So every radio was getting pretty close to exactly the same signal at its RF input.

Recordings were taken from the line output, if one was available, or the external speaker/headphone output otherwise. In either case, the audio was then isolated and converted to a balanced signal for recording.

For each signal, I recorded monaural “solo” tracks for each radio, as well as a narrated stereo track in which I compared the audio from each radio (one after the other) against the Icom R8600, with the audio from the R8600 on the left channel and the audio from the other radios on the right channel. This gives you a quick overview of what all the radios sound like.

The stereo recording requires some explanation. For it to make any sense, you MUST listen in stereo, using decent headphones if at all possible. You can switch earpieces back and forth (with your finger on pause and rewind) to get a quick idea of what each radio sounds like compared with a modern receiver, and how they handle things like fades and static.

The solo tracks, on the other hand, consist entirely of the continuous audio from a single radio, with no narration or interruption.

I recorded three different signals, for a three part comparison. (Parts four and up will come, hopefully, soon). I think both the differences and similarities will surprise you.

Part One

Our first signal was the BBC on 9915 KHz, broadcasting from Madagascar to western Africa. This signal was extremely marginal here, intended to show how each receiver can or can’t handle signals down in the noise. It’s definitely not “armchair copy”.

The stereo overview is at:

The individual receiver solo tracks can be found here:

Icom R-8600:

AOR AR-ONE:

Reuter RDR Pocket:

AOR 7030Plus:

Drake R8B:

Drake R7A:

Sony ICF-6800W:

Panasonic RF-4900:

Part Two

Our next signal was the Shannon (Ireland) aviation VOLMET broadcast on 5505 KHz USB. This synthesized voice gives the latest meteorological conditions at airports around Europe. The signal was not strong, but entirely readable. It shows how the radios handle a weak SSB signal. Note that the Sony and Panasonic consumer radios, though equipped with a BFO, were VERY hard to tune properly.

The stereo overview is at:

Receiver solo tracks can be found here:

Icom R-8600:

AOR AR-ONE:

Reuter RDR Pocket:

AOR 7030Plus:

Drake R8B:

Drake R7A:

Sony ICF-6800W:

Panasonic RF-4900:

 

Part Three

Our final signal was a stronger, though occasionally fading, shortwave broadcaster, Radio Romania International on 13650 KHz AM. This gives you a sense of how the receivers performed on a typical “average” signal that you might actually want to enjoy listening to. Because the radios have different filters and other capabilities, I tuned each radio to whatever sounded best; I did not attempt to use comparable settings (since no common settings existed).

The stereo overview can be found at:

And the individual solo tracks are here:

Icom R-8600:

AOR AR-ONE:

Reuter RDR Pocket:

AOR 7030Plus:

Drake R8B:

Drake R7A:

Sony ICF-6800W:

Panasonic RF-4900:

Subsequent comparisons, hopefully soon, will focus on receiver performance on signals in crowded bands and under various kinds of interference and noise.

A quick note on production: The recordings were made with a 12 channel Sound Devices 833 recorder with a Sound Devices SL-16 mixing console. The audio was isolated and converted to balanced output with Switchcraft 318 direct interface boxes (highly recommended for recording radios with pro audio gear).

The stereo track narration was done by me in real time, as the signals were being recorded. I made some comments about which receivers I thought sounded best that were not always the same as what I would later conclude after carefully listening to the solo tracks once back inside. But judge for yourself. I used a Coles “lip” microphone, an amazing ribbon mic designed decades ago for the BBC for use in highly noisy environments. It was very effective in reducing the sometimes considerable street noise and other ambient outdoor sounds.

Thanks for listening and 73!

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The “Signal Sweeper”: How to build a portable Wellbrook loop antenna

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Many thanks to SWLing Post contributor, Matt Blaze, for the following guest post:

The “Signal Sweeper”, a portable Wellbrook antenna setup

by Matt Blaze

Here’s a very simple construction project that’s really improved my travel shortwave and mediumwave listening experience.

When I go somewhere interesting (whether a day trip on my bike or a longer excursion to an exotic locale), the two things I’m sure to want with me are my camera gear and at least one good receiver. Fortunately, there are plenty of good quality shortwave receivers to choose from these days; the hard part is packing a suitably portable antenna that can do justice to the signals wherever it is I’m going.

I’ve long had a Wellbrook antenna on my roof at home. These wide-band amplified loops famously enjoy a reputation for excellent intermod and noise rejection, as well as an almost magical ability to pull in signals comparable to much larger traditional HF and MF receive antennas. A portable Wellbrook – something I could pack in my luggage that performs as well as the one on my roof, would be just ideal.

Fortunately, Wellbrook sells a “flex” version of their antenna intended for just this application, the model FLX1530LN. It’s essentially just the amplifier of their fixed-mount antennas, equipped with a pair of BNC connectors for you to attach a user-supplied ring of coaxial cable that serves as the antenna loop. This way, you don’t need to travel with the awkwardly large 1 meter diameter ring of aluminum tubing that makes up the normal Wellbrook. You can just bring a compact spool of coaxial cable and configure a loop out of it when you arrive at your destination.

The tricky part is how to actually form a stable loop out of coaxial cable without needing lot of unwieldy supporting hardware. In particularly, I wanted something that could be set up on a camera tripod to be freestanding and easily rotated wherever I happened to find myself wanting to play radio. The key would be finding or making some kind of mostly non-metalic support for the coaxial loop that could be folded down or collapsed to fit in my baggage or backpack for travel.

And then I found it: a humble 3-section telescoping broom handle sold on Amazon for about $15 that’s exactly the right size: the “O-Cedar Easywring Spin Mop Telescopic Replacement Handle“. It collapses to 22 inches (just short enough to fit in my suitcase), and extends to 48 inches (comfortably long enough for a one meter diameter loop).

Normally, a wire loop would need both vertical and horizontal supports in a cross configuration, but by using a reasonably stiff coaxial cable, I figured I could get away with just using the broom handle vertically. I found that LMR400 (the basic kind, not the “Ultraflex” version) holds its shape quite well in a one meter loop supported this way.

At this point, it was just a matter of the details of attaching and mounting everything together into a portable package.

A one meter diameter loop, which is the ideal size for the Wellbrook amp, can be made from 3.14 meters of cable (ask your middle-school math teacher). That’s about 10 feet for Americans like me. High precision is not required here, so I just cut 10 feet of LMR400.

The next step is to attach the middle of the cable to the top of the broom handle. The O-Cedar handle has a loop at the end for hanging it on a hook in your broom closet. It happens to be just the right diameter for LMR400, but not with BNC connectors attached. So you’ll have to thread the cable through before you crimp or solder on the with connectors. (See photo above). I used the Times Microwave crimp-on BNC connectors, which I had some extras of lying around. I also put some shrink wrap on the cable at either side of the broom loop, just to keep it from slipping out and becoming unbalanced, but that was probably unnecessary.

Now I needed a way to to attach the Wellbrook amplifier to the other end of the handle, as well as some way of mounting the whole thing to a camera tripod. My first thought involved a lot of duct tape. But I wanted something more permanent and reusable.

The key is something called an “L-Plate”, which is a piece of hardware intended to allow you to mount a camera to a tripod in either “landscape” or “portrait” mode. It’s basically two tripod dovetail mounts attached at a 90 degree angle. I used one that was in my junk box, but you can buy them new or used on eBay. I also needed a clamp to attach the L-plate to the broom handle. I used the Novoflex MiniClamp 26, which I got from B&H Photo. The clamp attaches to the inside of the L-plate with a captive screw. (See photos)

Next, I attached the amplifier to the other side of the L-plate using an ordinary screw-on hose clamp. Easy enough, and surprisingly sturdy.

And that’s it. To assemble the antenna, just extend the broom handle to about one meter, allowing for a roughly one meter diameter loop that’s as round as you can make it with the amplifier at the bottom. Then clamp the L-plate to the bottom of the handle so that the handle is just above the base of the plate, and attach to the tripod. (See the photos).

The Wellbrook is powered over the feedline with a 12VDC bias-T injector. So you need a clean source of 12 volts. I use a cheap Talent Cell battery pack (available on Amazon in various capacities). These actually deliver 11.1 VDC (3x 3.7V), rather than the 12V the Wellbrook calls for, but it works fine in practice. I can also use the same pack to power the radio and digital audio recorder.

In the photos, you can see the finished antenna setup on my roof, with my permanent base Wellbrook on the rotor in the background. The performance of the two antennas is quite comparable.

(Note that there’s an eBay seller that makes a somewhat similar travel loop. The performance is quite good under normal conditions, but it is a bit more subject to MW overload when near a transmitter site. So I prefer the Wellbrook, which is much less susceptible to overload, I’ve found.)

My usual complete travel setup is either a Reuter RDR Pocket C2 radio or a Sangean ATX-909X (recently upgraded to the X2 model). Both these radios work well with the Wellbrook. I use a Sound Devices Mixpre 3 to record airchecks in the field. In the photos, I’m on a rooftop DXpedition listening to Toronto traffic and weather from CFRX on 6070 kHz on a warm later winter afternoon.

The whole setup breaks down for travel pretty easily, and fits easily in my suitcase, backpack, or bike bag (see photos). I usually bring a larger tripod than this if I’m also taking my camera.

The Wellbrook setup has really made bringing a receiver into the field a lot easier and less uncertain. There’s no worry about finding trees or other supports for wires, and packing and unpacking is quick and easy. Have fun!

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Transmitters stuck in time

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Sometimes we radio enthusiasts discover odd things on the air.

We’re listeners and we notice things.

A few days ago our friendy, Matt Blaze, tweeted this:

Yep, for eight years a DDOT TIS (Traffic Information System) transmitter has been broadcasting the same repeating message and few have noticed.

You can read Matt’s whole Twitter chain here.

Matt has also kindly shared an audio recording of this transmitter. He notes that the reception “was weak but readable” from his home:

What’s more, Matt’s tweet was picked up by The Drive and turned into a post, thus exposing our radio geekery to the populos at large. Many thanks to the numerous SWLing Post readers who shared a link to the article.

I have to assume someone from the DDOT was paying attention too because Matt posted that as of March 3rd, it appears the transmitter has been taken off the air:

This reminded me of another transmitter stuck in time that I thought David Goren once mentioned. I checked with him and he confirmed:

Yes, there’s a transmitter somewhere on MW in NYC that has been broadcasting: “this is a functional test of the text-to-speech capability of the [VR or BR 2000] software package”. They’ve probably been on at least 10 years.

Many thanks to David for sharing the following recording:

Have you ever heard a forgotten transmitter? Please comment with details!

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Matt’s Monster Mediumwave Radio Selectivity Shootout!

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Many thanks to SWLing Post contributor, Matt Blaze (WB2SRI), for sharing another brilliant audio comparison featuring benchmark portable radios:

Medium wave selectivity shootout

by Matt Blaze

I did another monster medium wave portable receiver comparison, this time with the aim of comparing receivers’ ability to deal with weak signals in the presence of strong adjacent channels.

Once again, I went up to the roof with eight MW portables with built-in antennas and recorded them simultaneously along with my “reference signal”, from an Icom R-9500 with an active loop on the roof. As before, I recorded a narrated stereo mix with the Icom on the left and the rotation of radios for a minute or two each on the right, but have “solo” tracks available for the full time for each radio. The nine receivers in the lineup this time included:

  • Icom R-9500 (with amplified Wellbrook loop antenna on roof)
  • Potomac Instruments FIM-41 Field Intensity Meter (my personal favorite)
  • Panasonic RF-2200
  • Sony IC-EX5MK2
  • C.Crane Radio 2E
  • Sangean PR-D4W
  • Sangean ATS-909X
  • Tecsun PL-990X
  • XHDATA D-808

I recorded two signals, one at night and one during the day.

Nighttime Signals

The first was at night: WWL New Orleans on 870 KHz. This signal is usually weak to medium strength here, but is a challenge for two reasons: first, it shares the frequency with Cuba’s Radio Reloj, and it is squeezed between two much higher strength signals: Toronto’s CJBC on 860, and NYC’s WCBS on 880. So you need a decent receiver and careful antenna orientation to receive it well here. That said, everything did pretty well, though you can see that some radios did better than others.

The mix

Solo tracks

Icom IC-R9500

Potomac Instruments FIM-41 Field Intensity Meter

Panasonic RF-2200

Sony IC-EX5MK2

C.Crane Radio 2E

Sangean PR-D4W

Sangean ATS-909X

Tecsun PL-990X

XHDATA D-808

Daytime Signals

The second signal was during the day and was MUCH more marginal: WRJR Claremont, VA on 670 KHz. This was real challenge for any receiver and antenna. The signal was weak, and overshadowed by WCBM Baltimore on 680, a 50KW daytimer that is very strong here. (I’m not 100% sure that we were actually listening to WRJR – I never got an ID, but the station format and signal bearing was right). We can really hear some differences between the radios here.

The mix

Solo tracks

Icom IC-R9500

Potomac Instruments FIM-41 Field Intensity Meter

Panasonic RF-2200

Sony IC-EX5MK2

C.Crane Radio 2E

Sangean PR-D4W

Sangean ATS-909X

Tecsun PL-990X

XHDATA D-808

Everything (except the Icom) was powered by batteries and used the internal MW wave antenna, oriented for best reception by ear (not just maximizing signal strength, but also nulling any interference). The loop for the Icom was similarly oriented for best intelligibility.

For audio nerds: The recording setup involved a lot of gear, but made it fairly easy to manage capturing so many inputs at once. The portable radios were all connected to a Sound Devices 788T recorder, with levels controlled by a CL-9 linear mixing board control surface. This both recorded the solo tracks for the portables as well as providing a rotating mix signal for each receiver that was sent to the next recorder in the chain, a Sound Devices 833. The 833 received the mix audio from the 788T, which went directly to the right channel. The left channel on the 833 got audio from a Lectrosonics 822 digital wireless receiver, which had the feed from the Icom R-9500 in the shack (via a Lectrosonics DBu transmitter). The center channel on the 833 for narration of the mix, which I did with a Coles 4104B noise-canceling ribbon mic. This let me record fairly clean audio in spite of a fairly noisy environment with some wind.

All the radio tracks were recorded directly off the radios’ audio line outputs, or, if no line out was available, from the speaker/headphone jack through a “direct box” interface. I tried to make the levels as close to equal as I could, but varied band conditions and different receiver AGC characteristics made it difficult to be completely consistent.

Making the recordings was pretty easy once it was set up, but it did involve a turning a lot of knobs and moving faders in real time. I must have looked like some kind of mad scientist DJ to my neighbors, some of whom looked at me oddly from their own roofs.

Happy Thanksgiving weekend!

Thank you, Matt, for another brilliant audio comparison! I appreciate the attention and care you put into setting up and performing these comparisons–not an easy task to say the least. That Potomac Instruments FIM-41 is an impressive machine!

By the way, I consider it a badge of honor when the neighbors look at me as if I’m a mad scientist. I’m willing to bet this wasn’t your first time! 🙂

Post readers: If you like this audio comparison, please check out Matt’s previous posts as well:

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Matt’s Marathon MediumWave Matchup

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Many thanks to SWLing Post contributor, Matt Blaze (WB2SRI), who shares the following guest post:

Matt’s Marathon MediumWave Matchup

by Matt Blaze

Here’s another simultaneous receiver comparison, this time of ten portable medium wave receivers plus the Icom IC-R9500 (as a “reference receiver”). Previously, I used the same antenna for all the comparisons, but since these are portable receivers, I wanted to compare their performance using their built-in antennas. I did two comparisons, both of moderate to weak signals, one in the evening of a DX signal and the other in the daytime of a regional station.

The receivers were the Potomac Instruments FIM-41 (a “field intensity meter”), the Panasonic RF-2200, the Nordmende GlobeTraveler Exec (a beautiful German SW portable from 1968), the Sony ICF-EX5MK2, the CCrane Radio 2E, the Sangean ATS-909X, the Sangean D4W, the new Tecsun PL-990X, the XHDATA D-808, and finally the CountyComm GP5-SSB, plus the Icom IC-R9500.

All the receivers were recorded simultaneously. The radios (except the Icom R9500) were on the roof of my building and oriented for best reception (signal/noise) and kept sufficiently away from each other and other metal objects to avoid interference, The R9500 was in the shack and used a Wellbrook loop on the roof, also oriented for best signal/noise. I took the audio from the Line Out if one was available and from the headphone jack (via a “direct box” level converter) if not. I tried to match the audio levels reasonably closely, but different ACG characteristics made it difficult to be completely consistent across all the receivers throughout the sessions.

As in previous comparisons, for each session I’ve got a narrated stereo mix with the R9500 on the left channel and each receiver, for a minute or so one after the other on the right channel. You definitely want to use headphones to listen to these so you easily tell the left from the right radio. I’ve also provided mono “solo” recordings of each receiver for the full 15 minute-ish sessions so you can hear a receiver you’re interested in in detail.

Sound Devices 688 Multitrack Recorder

The recordings were made with a Sound Devices 688 recorder/mixer (which can record 12 simultaneous channels of audio). The portable radios were hardwired to the recorder, and the 9500 (which was downstairs) was connected via a Lectrosonics digital radio link. (Everything except the R9500 was on battery power to avoid mutual interference and ground loops, etc). The narration used a Coles noise canceling ribbon mic. Everything was done in a single take per session – there was NO postproduction editing – so I apologize for a few glitches and awkward moments.

You can see a “class photo” of the setup below, although the position and orientation of the radios was different during the actual recordings.

KCJJ

The first recording was at night, where we tuned to 1630 KCJJ in Iowa City, IA. This is effectively a 1KW clear channel; other than a few TIS stations, there’s not much else there on the east coast, and the signal is reliably weak to moderate but readable here on the east coast.

Narrated L/R stereo comparison:

Individual solo tracks:

CCrane Radio 2E

Sangean D4W

XHDATA D-808

Sony ICF-EX5MK2

Potomac Instruments FIM-41

CountyComm GP5-SSB

Nordmende GlobeTraveler Exec

Tecsun PL-990X

Icom IC-R9500

Panasonic RF-2200

Sangean ATS-909X

WSVA

The next recording was made during the day, of WSVA, a regional station in Harrisonburg, VA running 5KW in the daytime. Their signal is also reliably weak-moderate but readable here.

Narrated L/R stereo comparison:

Individual solo tracks (receiver should be obvious from the file name):

CCrane Radio 2E

Sangean D4W

XHDATA D-808

Sony ICF-EX5MK2

Potomac Instruments FIM-41

CountyComm GP5-SSB

Nordmende GlobeTraveler Exec

Tecsun PL-990X

Icom IC-R9500

Panasonic RF-2200

Sangean ATS-909X

Hope your readers find it useful!

-matt

An absolutely amazing job again, Matt! Thank you so much for taking the time to put this comparison together and sharing it here on the SWLing Post.  

Click here to check out all of Matt’s receiver audio comparisons.

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