Shortwave listening and everything radio including reviews, broadcasting, ham radio, field operation, DXing, maker kits, travel, emergency gear, events, and more
Many thanks to SWLing Post contributor, 13dka, who shares the following guest post:
The Icom IC-705: Is this really a new holy grail SWL/BCL receiver?
by 13dka
When Thomas got wind of its development in 2019 he immediately asked “could the Icom IC-705 be a shortwave listeners holy grail receiver?”. I usually wince a little when I hear “holy grail” because it means very different things to different people, it’s also a moving target with many people aiming at the spot where it was decades ago. But Thomas certainly had a very level-headed assembly of technical performance, quality and practicality requirements in mind when he used that term, and I thought he might be onto something!
There are some excellent, trustworthy reviews of the IC-705 out there. The following is not one of them, I just want to share an opinionated breakdown on why I think this is an interesting radio for SWLs/BCLs indeed, also deliberately ignoring that it’s actually a transceiver.
Jumping shop
While the era of superhet/DSP-supported tabletop holy grails ended with the discontinuation and sell-off of the last survivors more than a decade ago, powerful PC-based SDR black boxes were taking over the mid-range segment and it became very slim pickings for standalone SWL receivers: Thomas just recently summed up the remaining options here.
Between the steady supply of inexpensive yet serviceable Chinese portables, upgraded with a least-cost version of DSP technology, and the remnants of the high end sector there’s very little left to put on the wish list for Santa – that doesn’t need to be paired with a computer that is.
No surprise that SWLs/BCLs in search of new quality toys with tangible controls are taking a squint over the fence to the ham transceiver market: Hams are still being served the best and the latest in radio technology in all shapes and sizes, and even entry-level rigs usually come with feature-rich general coverage receivers. But transceivers never had SWLs much in their focus in the past decades, and particularly not BCLs: Frontend adaptation, additional AM filters, switches and functions would’ve meant increasing costs and so transceivers were never perfected for that purpose. DSP and SDR technology allowed for improvements on that without actually adding (much) hardware and so some interesting alternatives surfaced in the past years, but most of them still come with little downers, at least for BCLs.
access to the full archive of Medium Wave News (all 500 issues)
access to the latest 2020 Editions of the All Time DX Heard in the British Isles
a new section for news and feature articles
a completely new and re-written library
For the first time we also host the archive of the European MW Guide which was the most
complete directory of radio stations in Europe.
All the content is either new or completely revised and updated. Most importantly we want our website to be unique and that is why the features, photos, QSLs and audio clips are not to be found elsewhere online.
The new website has been carefully designed to work on desktop PCs, laptops, ipads and even smartphones. It has also been updated to improve security – you will notice the https web address & the padlock next to the url in your browser.
Many thanks to SWLing Post contributor, Giuseppe Morlè (IZ0GZW), who shares the following video and notes:
I recently bought a Tecsun S-8800 to be used mainly on shortwave. I carry it in an aluminum case to use it everywhere:
Many thanks for sharing this, Giuseppe! I love the integrated antenna–so clever!
Post readers: Giuseppe has had issues with the S-8800 accidently turning on in the case. Can anyone describe the button combo needed to lock the dial and controls during transport? I checked the manual but have found no reference. Please comment if you can help!
After listening to the BBC “Re-Tune” broadcasts, it reminded me of when the United States had its own “Re-Tune” day on March 29, 1941. It was referred to as “Moving Day”.
At 3:00 am, 802 of the 890 radio stations moved frequency. Following are a couple of articles about this day:
I love how it was used as an opportunity to get the radio listener to call on the radio technician to re-program the radio push buttons. And of course while the technician is there, have him do a full alignment and maybe replace a tube.
The March 1941 issue of Radio and Television Retailing (Pages 16-17) had the article “Radio’s Opportunity for Contact”.
While the entire article is an interesting read, the first few paragraphs sums up the opportumities:
THE OPPORTUNITY for contact with consumers using pushbutton-tuned radios., afforded by dramatic March 29 broadcast station frequency shifts, represents an absolutely unique invitation to move more major merchandise, with the promotional expense at least partially covered by service and accessory sales.
Imagine what slick automobile salesmen could do if roads were suddenly altered in such a manner that 10,000,000 cars required some adjustment to operate properly, what refrigerator salesmen might accomplish if a change in current necessitated motor manipulation, how laundry equipment salesmen would positively gloat over the glut of prospects if that many people with old machines actually asked them to call.
Calls make sales, as the records of many home specialty retailers conclusively prove, and the beauty of this particular opportunity to make them lies in the three-fold fact that cold-canvassing is completely unnecessary, that the motivating power of any campaign built around it is obviously not just trumped-up by the trade and that only dealers selling or servicing radios can capitalize in all departments of their business.
So valuable from a major merchandising sales angle is the opportunity to call upon consumers afforded by the necessity for changing pushbutton settings that we suspect many radio retailers will hesitate to charge for this adjustment.
This may be particularly true where consumers so contacted are obviously prospects for new merchandise and will undoubtedly occur in some instances where customers are still being carried on time-payment accounts.
The Feb 1941 issue of Radio Service-Dealer (Page 8) also stressed the opportunities.
Reallocation of Broadcast Frequencies M arch 29th Opens Big Job For Service men Resetting Nation’s Push-Buttons
YOUR JOB
There are approximately 10 million push-button receivers in operation in this country. It will be your job to re-set the buttons for the new frequencies in the shortest possible time and with the least amount of confusion. It will also be your job and your opportunity to inspect these receivers for faulty operation. No such opportunity is likely to present itself again, so make the best of it.
And on page 7 of the Mar 1941 issue of Radio Service-Dealer has the article FREQUENCY REALLOCATION SERVICING PROBLEMS
1A—If a station with a strong signal intensity happens to be operating on double the frequency of the intermediate frequency of a receiver, there is liable to be a heterodyne whistle. The frequency of 455 kc has been used as the standard intermediate frequency on receivers manufactured in the United States. One main reason for selecting this frequency was that the broadcast frequency of 910 kc was assigned to Canada and, therefore, the possibility of a heterodyne note being produced on a receiver in the United States was at a minimum. Under the terms of the reallocation several American stations will be moved to 910 kc thus producing a problem in the cities where these stations are to be located. If a heterodyne note is heard due to this cause the remedy is to shift the intermediate frequency to one side or another.
Thank you, Bill, for shedding more light on Radio Moving Day and, especially, providing us with the broadcaster and technician’s point of view.
Many thanks to SWLing Post contributor, TomL, who shares the following guest post:
Comb Stereo on Shortwave
by TomL
Comb Stereo is an old technique being implemented over shortwave by the main sound engineer (Daz) at Radio Northern Europe International (RNEI). It ONLY works on Comb Stereo broadcasts which currently are RNEI, This Is A Music Show (WRMI), and one of the KBC broadcasts. It works in real-time or for SDR recorded files, too. It does NOT need a special HD/DAB+ radio.
A number of pluses for Comb Stereo on shortwave compared to digital:
“The bandwidth is the same as mono – So the SNR should be about the same as mono.
Selective fading doesn’t affect the comb bands much, so the balance is largely unaffected by selective fading notches.
The Comb Stereo artifacts are much like typical music effects of echo, chorus, fast reverb or room reflections.”
An enhanced version is broadcast on WRMI for the RNEI time slot on Thursday morning (01:00 UTC) on 5850 kHz. It sounds very good and is not a pseudo-stereo like in my previous article, Music on Shortwave. For one thing, pseudo stereo is not real two-channel encoding and shifts vocals to one side, depending on which channels are chosen for high and low filters, which might get annoying after awhile. What seems amazing to me is that I have been able apply some minor noise reduction in Audacity and the Comb Stereo stays perfectly intact. It also still works after converting the WAV file to MP3 and sounds much like a regular FM broadcast. Furthermore, it does not require a special patented transmitter or receiver chip. It is compatible with regular mono transmitters.
If you want to try it, go to the RNEI web site; download and install the two files listed (VB Audio Cable and CombStereo Pedalboard x64):
It is slightly tricky to setup and use or you will not hear anything (most Windows systems default to 48000 Hz these days). Right-click on the lower-right taskbar Sounds settings. Make sure to setup Properties – Advanced in both the VB-Audio Virtual Cable (Playback and Recording) and your output speakers (Playback) to 24-bit 44100 Hz processing.
Now run the app Pedalboard BAT file which corresponds to the broadcast you recorded (in this example “Start Comb Stereo for WRMI.bat”). Set the Options – Audio Settings:
Since the VB-Audio Virtual Cable takes over your volume output, adjust the volume of your Speakers in Windows’ Sounds – Levels (or you can adjust the volume in the sound player you are using, too):
Play the mono WAV or MP3 file and you should be hearing stereo!
When you are done, close Pedalboard2 and then disable the VB-Audio Virtual Cable for Playback and Recording to get your Sounds back to normal:
I cannot demonstrate what it sounds like unless you have the VB-Audio Virtual Cable and the Comb Stereo app setup and working properly. Here are snippets from recent RNEI broadcasts captured by my noisy porch antenna:
Here are links to the artists’ YouTube videos for comparison:
What is nice is that I can create a space-saving MP3 mono file and this setup will decode the stereo when run from the computer (sounds really nice on a stereo system with a subwoofer). Unlike digital, this analog-friendly stereo seems mostly immune to fading, has a minimum of digital artifacts, and will not go silent and “drop out” like digital does for long, annoying periods of time. It is not perfect stereo but audio players with features like Stereo Widener or Windows Sonic for Headphones can overcome some limitations. Perhaps content providers should consider Comb Stereo for all their shortwave radio shows since it is perfectly compatible with mono AM transmissions!
A few weeks ago, Chameleon Antenna sent me a pre-production model of their new wideband magnetic loop antenna called the Chameleon CHA RXL.
I’ve evaluated and reviewed a number of Chameleon’s ham radio antennas (primarily on QRPer.com). I find that the quality of their products are second to none. Price-wise, they tend to be at the top of the market, but keep in mind they machine and manufacture all of their antennas here in the US and they’re incredibly rugged; indeed, military-grade. And in the spirit of full disclosure, I’m proud Chameleon has been a sponsor the SWLing Post and QRPer.com since last year. My sponsors are by invite only and focus on companies I trust with our radio community’s business.
When Chameleon shipped the CHA RXL to me, it wasn’t from their factory, it was directly from the field: Fort Irwin, to be exact.
(Source: NTC Operations Group, Ft. Irwin)
This CHA RXL sample had been used by NTC Operations Group Fort Irwin (who, incidentally, won QRPX this year–click here to read the PDF report).
I was told that the condition of the antenna could be very rough after the QRPX because it had essentially been sandblasted in the desert winds. I was also told that someone accidently transmitted 5 watts into it at some point but it didn’t seem to harm it (for the record, like all amplified receive-only loops, it’s not designed to take RF).
Tony (W0NTC), who was one of the Ft. Irwin radio ops, sent me this note as he dropped off the shipment at Fort Irwin’s FedEx:
“Had a blast with [the CHA RXL], and it was absolutely critical while I was operating in the Army HF Low Power Competition (think tons of high powered MARS stations piling up and drowning out the 20W or less competitors). It absolutely crushed some localized RFI from a huge building I operated behind, and the receive on it I can only describe as “layered” in that I could hear stations somewhat clearer than usual if they transmitted simultaneously. Receiver I used was the IC-705 with default Auto Notch and Noise Reduction.”
Tony volunteered all of this info–I never asked him how it performed.
A few days later, I wasn’t sure what to expect when I opened the box although I knew that my operating locations were nowhere near as cool as its position next to a Humvee at Fort Irwin in the photo above!
I pulled the CHA RXL out of the box and it looked cosmetically flawless to me.
Frankly, there’s not a lot to get damaged. The 36 inch diameter loop is made of rigid aluminum and has a Navy gray powder coating. The preamplifier unit is completely sealed and made of a high-impact plastic/PVC type material. The steel loop is attached to the preamplifier loop flanges with wing nut connectors.
The only potentially vulnerable part of the antenna system is the Bias-T box which would normally be located in your shack close to your receiver.
If I mounted the CHA RXL permanently outdoors, I would use Coax Seal around the BNC connection point, of course.
Although the CHA RXL has a supplied mounting bracket for permanent installations, I love the fact that the preamp box has a 1/4” x 20 threaded camera socket on the bottom. This makes for a brilliant portable loop because it can so easily be mounted on a standard heavier-weight tripod! All antenna manufacturers should give us tripod mount options when possible.
On the air
One of the reasons amplified receive loop antennas have become so incredibly popular over the past couple of decades is because they do an amazing job mitigating radio frequency interference (RFI) a.k.a. “QRM.” If you live in a neighborhood with significant radio interference, you really should consider some form of loop in your antenna arsenal.
Ironically, at home, I live in pretty much an RFI-free zone. I’m surrounded by tens of thousands of acres of national forest, so I’ve only used amplified loop antennas in the past for mediumwave DXing–mainly, when I wanted to take advantage of their amazing ability to null out unwanted signals.
Many years ago, I purchased a Pixel Loop Pro antenna (now under a different name via DX Engineering), mounted it outside where it lasted almost a year before a bear decided to pull it down and chew through the coaxial feedline. He/she did so with enough energy that it ripped down the loop and damaged the connector end of the Pixel’s pre-amp. This all happened when our family was travelling for two months in Canada. Why bear, why?!? But I digress…
The CHA RXL version I was shipped has one single rigid loop–the “EU” version’s loop comes in two pieces (for easier shipping/transport)–but I had no problem fitting the entire assembled loop in the back seat of my Subaru or my truck (as long as no one was sitting back there at the time). If you plan to travel with your loop a lot, consider the “EU” version!
I’ve taken the CHA RXL to my parent’s home a couple of times and enjoyed doing a little mediumwave and shortwave listening. Inside the house, the loop would attenuate RFI nicely, but when outside it would all but eliminate many sources of RFI.
At their house, I primarily used my Icom IC-705 for cruising the bands (being careful, of course, to disengage the transmit function).
Listening time in my hometown, though, was very limited. Since the CHA RXL is so portable, I decided to set it up at home on our porch for a few days, giving me an opportunity to test both the Sangean ATS-909X2 and Tecsun H-501x with an external antenna.
I’ve especially appreciated using the CHA RXL on mediumwave. Even from our screened-in porch, I can rotate the loop and use its excellent nulling properties to pick out multiple station IDs on crowded frequencies.
I’ve spent time on shortwave, too, and found that it certainly gave these two portables a signal boost.
In fact, it was by using the CHA RXL that I discovered the audio level difference between AM and SSB on my ATS-909X2 is very minimal when an external antenna is connected.
I’m sure you’ll hear the CHA RXL in action when I post audio clips and recordings in upcoming reviews.
Summary
If I owned a CHA RXL loop, one of the first things I’d do is build a power cord for it with an in-line fuse and terminated with an Anderson Powerpole connector. Since the operating voltage of the Bias-T is 12-14 VDC, it would pair perfectly with one of my Bioenno LiFePo4 batteries, offering a power source with longevity in the field–ideal for a group LW/MW/SWL DXpedition.
It’s difficult for me to truly comment on the loop’s performance because I don’t have another loop at present for comparison. I can say that it’s amazing on mediumwave, where I’ve spent much of my listening time this past week. I believe shortwave reception has been at least on par with my former Pixel Loop, if not better. It’s hard to say, in truth, because propagation conditions have been so poor lately. The CHA RXL loop does effectively mitigate noise!
I’m not sure if the CHA RXL is currently on backorder or not, but I would suggest you check out the product page on Chameleon’s website and possibly contact them if you’re interested. They’ve a number of options and accessories to consider.
One thing for sure: this must be one of the most rugged and durable RX loop antennas on the market. In addition, that Navy gray powder coating helps this rigid aluminum loop disappear against the sky. I believe you could strategically mount this loop and the friendly neighborhood association may never notice–it’s pretty stealthy. Speaking of which…
Josh’s CHA RXL install and demo video
Josh over at Ham Radio Crash Course recently installed a CHA RXL on his house and tested it on several bands, comparing it with a number of his external antennas:
Many thanks to SWLing Post contributor, 13dka, who shares the following guest post:
