Recently, he submitted a very unique recording. Tom notes:
Rudy Espinal of Radio Clarin (Dominican Republic) keynote speech at 1979 Association of North American Radio Clubs (ANARC) convention held in Minneapolis, Minnesota. Convention took place in June 1979.
In this recording, you’ll hear a number of familiar names (including an early shout-out to our friend Kim Elliott).
I was in elementary school at the time of this convention, so it’s amazing bit of audio time travel for me.
Do you recognize any names in this recording? Do you remember Radio Clarin? Did you attend the 1979 ANARC Convention? Inquiring minds want to know! Please comment!
The original files are in .wav, archive.org converts them to mp3 and flac. Files with sas in them are supposed to be in stereo. There are many shortwave recordings in it, as well as mediumwave.
For anyone who is hunting IDs, Japanese radio stations definitely announce their full ID at 5 AM Japan Standard Time each day. On the top of the hour commercial radio stations ID. On Mondays between 1 and 2 AM (commonly given as between 25:00 and 26:00 Sundays on Japanese radio schedules) many Japanese radio stations go off the air for transmitter maintenance and give a very full, 5 minute long ID. I believe I have included one that I clipped for 1008 AM in Osaka in this month’s collection; 1008 AM, JONR is definitely in full AM stereo.
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.
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
Potomac Instruments FIM-41
Nordmende GlobeTraveler Exec
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
Potomac Instruments FIM-41
Nordmende GlobeTraveler Exec
Hope your readers find it useful!
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.
Many thanks to SWLing Post contributor, Matt Blaze, who writes:
I did another head-to-head receiver comparison, this time of two MW BCB AM portables: The C.Crane Radio 2/e vs. the Potomac Instruments FIM-41 field intensity meter.
The latter is not intended as a receiver, but rather a test instrument, but it turns out to be the among most sensitive MW receivers I’ve ever used. So I thought it would be interesting to compare its performance with that of a well-regarded modern portable.
Our two contenders with comparable portable radios: the GE Super Radio, Panasonic RF-2200, and Sony ICF-EX5MK2.
Another brilliant audio comparison, Matt! Thank you so much for taking the time to put this together! I actually believe audio comparisons, as you’ve set them up, are a fantastic way of sharing A/B comparisons.
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…
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.
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.
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.
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
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
In 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
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
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
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+
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.
In my previous post, I mentioned how much I enjoy the built-in digital audio recorder in the new Icom IC-705. While I wouldn’t buy a QRP transceiver specifically for built-in audio recording–there are less expensive options out there–it is an incredibly useful feature in my world.
Their house is like so many others in that it is inundated with RFI (radio frequency interference). I find that the NCPL antenna does a fine job mitigating most of that noise on the mediumwave band when I position it so that the bulk of the interference is nulled.
Monday morning, I tuned the IC-705 to my favorite local AM station: WAIZ on 630 kHz.
Weekday mornings, Dave and his “Wacky Wake-Up Crew” always put me in the right mood. They’re incredibly goofy/corny and 100% original.
It’s extraordinarily rare these days to find a local radio station, with local talent, creating a local daily radio show. Almost all of their ads are local, too.
I made the following off-air recording for myself, but decided to upload it for others to enjoy. I’m not sure what the receiver audio EQ or bandwidth filter was set to when I recorded this. It’s not a demo of receiver performance, just a little radio fun.
Spread the radio love
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