Many thanks to SWLing Post contributor, Grant, who writes:
Hi Thomas,
In case it hasn’t crossed your path yet, Alan put out a nice review of the GP-7 yesterday. He has a gift for explaining things…
Click here to view on YouTube.
He does indeed! Thank you for sharing this, Grant!
Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post:
The noise, the neighbor, and the boxBy Jock Elliott, KB2GOM
Imagine the annual meeting of an international corporation called SWLing Inc. (or SWLing LTD). The CEO, looking splendid in his custom-tailored suit, is addressing the assembled multitudes. On the giant screen is an equation showing signal-to-noise ratio. The CEO aims his laser pointer at the word “signal.” We want ALL of this, he says. Then he points at the word “noise,” and says, “and NONE of this.”
Then he looks at the audience and says, “Got it?” And he walks off the stage.
That, whether they want to admit it or not, is the mindset of every single SWL, international music fan, overseas program listener, and DXer. Period. They want as much signal as they can get, and as little noise as possible. That’s what drives radioheads to buy amplified loops, to string long wires, to build towers and yagi antenna arrays, to lay out beverage antennas hundreds of feet long, and to build ferrite sleeve loop antennas . . . it’s all about the signal to noise radio. More signal, less noise.
And it was noise that was bothering me . . . a kind of hiss, hash, eggs-frying sound. It was that noise that prompted me to create the horizontal room loop to try to boost the signal coming into my Grundig Satellit 800 over the noise normally received on the Satellit’s whip antenna.
And it worked; there was more signal on top of the noise . . . but that hiss, hash, whatever you want to call it, was still there. I could hit the attenuator, and some of the noise would go away, but it was still there. After a while, it was just plain tiring on the ears. Poking around the internet, the wisdom seemed to be that the source of the noise was likely electric/electronic gear in my radio room. So I killed the power to everything in my radio room, powered the Satellit 800 off internal batteries, and the noise was still there.
So I called my neighbor. He’s (a) a really good neighbor, (b) a ham with a serious station, and (c) technically knowledgeable. I explain the problem. He says, “Meet me outside.”
We meet between the yards, and he has a Sony 7600 portable shortwave radio in his hand. He switches it on. “Is this the noise you’re talking about?”
“Yup,” I say. “That’s the atmosphere,” he says. Well, nuts.
More poking around the internet reveals that an amplified receive-only magnetic loop antenna might be significantly quieter, and there are several manufacturers of them. I’m thinking about one of those loops when I run across a review of a relatively inexpensive ham transceiver that is reported to be excellent at pulling difficult signals out of the noise because of the superior “digital signal processing” (DSP) that is built into the transceiver.
Digital signal processing . . . that sounds promising . . . after all, if you take a step back and think about it, there are two ways to improve signal-to-noise ratio. One way is to improve the signal with better antennas and the like. The other way is to reduce the noise, and one way to achieve that might be through digital signal processing.
So, are there any companies that make external digital signal processors that could be used with an HF receiver? There are several, it turns out. Some of the units are large, studded with knobs and look complicated to operate, and almost all of the offerings require an external power supply.
But I wanted something that could be easily transferred between receivers and might even be used with a portable receiver when I was doing my horizontal DXing in bed. A big box that requires an external power supply was going to be awkward, cumbersome, and inconvenient. And that’s when I ran into a British company called BHI. They make noise cancellation products, gizmos that use digital processing to remove noise from an audio signal. They serve amateur radio, commercial, marine, medical, and even covert surveillance markets.
One of their products is the Compact In-line Noise Eliminating Module. It can be run off AA batteries and isn’t much bigger than a deck of cards (in fact, its footprint is almost exactly the same as my CCrane Skywave SSB). It has just two knobs and is easy to set up: you just plug it in between your HF receiver and your headphones or external speaker. It even comes with a cable to connect your receiver to the Noise Eliminating Module.
I order one from DX Engineering in Ohio. The cost, delivered to my door, including tax, is just over $260 American dollars. It arrives two days later, just in time for the bands to be sizzling with noise (apparently) produced by a solar coronal mass ejection (CME). The amount of noise is brutal, about as bad as I have ever heard in decades of hamming and SWLing.
Plugging the BHI in-line module into my Satellit 800 and clamping the headphones over my ears, I begin tuning the 20-meter ham band. Part way up the band, I run into a Canadian ham chatting with someone. His signal is barely above the noise and copyable, but the noise is really annoying. I punch the button for the BHI device, and . . . the noise disappears. Wow! I press the right-hand button (to bypass the BHI device), and the noise comes back full force.
Quickly, I grab my Tecsun PL-880, extend the whip antenna, tune to the same frequency, and plug the BHI in-line module into the 880. The noise sounds even worse on the 880 (the Canadian ham is barely copyable), probably because of the shorter antenna. But when I engage the BHI device, the result is even more dramatic; a very pleasant signal emerges as the BHI unit suppresses the noise, with just a bare hint of hiss still audible.
Then I take hold of my CCrane Skywave SSB to see how the BHI in-line module will behave with that. It doesn’t take long to realize that, apparently because of the solar activity, all the bands are noisy on the Skywave. Not just shortwave, but AM, FM, weather, and Air were all uncharacteristically affected by hiss or noise. The BHI Compact In-line Noise Eliminating Module reduced the noise and made each of them more pleasant to listen to, without exception. I am “officially” impressed.
As I experiment with the BHI device in following days, during which atmospheric conditions improve, I continue to be impressed. Why? Because the BHI Compact In-line Noise Eliminating Module is effective at substantially reducing noise without a lot of fuss and bother.
As good as the BHI module is, though, it is not a miracle device; it does have some limitations. Sometimes it will not eliminate all the noise, even though the noise will be reduced substantially. If you crank up the level of filtering/noise cancellation too high, it can distort speech and make tuning single sideband difficult. Further, you sometimes hear artifacts of the digital signal processing. These artifacts sound to me like trickling water, and, frankly, I don’t find these sounds objectionable (they sure beat the heck out of the atmospheric noise), but some people, I suppose, might not like them.
Image via DX Engineering
The module is easy to operate. There are two knobs. Press the left one in to power up the unit, then turn the knob to adjust the volume. Press the right knob to activate noise reduction and then turn the knob to adjust the level of noise reduction. Sometimes, I find, the sweet spot for listening is with the noise substantially reduced – perhaps 85-90 percent – but not completely gone. Press the right knob again to bypass noise reduction and hear what the signal sounds like without the BHI module online.
Because the two knobs on the face of the BHI module are also push-buttons, if you are going to pack the device in your luggage, remove the batteries to prevent the unit from inadvertently turning on and draining the batteries.
The BHI Compact In-line Noise Eliminating Module is highly effective at reducing or eliminating noise. It works on international broadcasters, ham single-sideband signals, and utility stations, as well as AM, FM, and even NOAA weather radio when conditions are horrible. It can make weak signals easier to hear and strong signals more pleasant for long-term listening. It reduces audio fatigue. It is not a cure-all for all signal-to-noise or audio problems, but it is a big help. Further, it can be readily moved from location to location and from radio to radio and adds a new capability to receivers that do not have built-in digital signal processing.
I think it is a worthwhile addition to any shortwave listening post.
Many thanks to SWLing Post contributor, Gary DeBock, who shares the following notes and video:
The 7.5 inch (19cm) loopstick Radiwow R-108 model “smokes” the stock R-108 model in this video demonstration of receiving daytime DX fringe station 550-KARI in Blaine, WA (5 kW at 150 miles). The modification uses the same enhanced loopstick as described in the XHDATA D-808 “Supercharging” article, and is reasonably easy to complete (although some experience is recommended)
Many thanks to SWLing Post contributor, Dan Robinson, for the following guest post and review:
by Dan Robinson
It’s been a long wait, but CountyComm, that supplier of all kinds of neat and useful stuff, finally released the GP7 SSB (Gen 4).
As the name states this is the 4th generation of the series of radios adapted by the company from the Tecsun PL-36xxx series of receivers (there was at one point a GP6 that was a never-released special project).
All photos by CountyComm
This walkie-talkie style, though receive-only, portable has undoubtedly been a big seller for CountyComm since the first model came out. It’s popular not only with SWLs and amateur operators but also with preppers.
When OEM Tecsun finally did what everyone was clamoring for – redesign the radio with a keypad and including features associated with the PL-880/330/990x/501x receivers – the ground shook. Continue reading
Many thanks to SWLing Post contributor, Dan Robinson, for the following guest post and review:
Two Chinese Clones: A Look at Noise LevelsArriving recently here in the radio shack, were a Chinese clone under the name of “Fire Brothers” and another under the name HFDY. I thought it would be constructive to note the key differences between these two clones, both of which are running Malahit 1.10c firmware, and post some video of a brief comparison.
A note in advance of any comments – I am primarily a HF listener so these comparisons do not cover frequencies above 30 MHz. For those whose focus is on higher frequencies I recommend looking through the many comments on the Malahit Facebook group and Telegram by those who use these receivers in those ranges.
Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post:
Confessions of a horizontal DXer and some initial impressions of the Tecsun PL-880by Jock Elliott
Back in the day when I wrote for Passport To World Band Radio, one of my favorite things to do, while my better half drifted off to sleep, was to clamp on a pair of headphones, lean back against the pillows, and mess around with a Sony 6800W shortwave receiver.
It wasn’t a radio that was built for band scanning: you had to rotate a dial to select the megahertz segment of the bands that you wanted, tune a built-in preselector to the appropriate area, and then dial in the frequency with a tuning knob. And memories? Ha! You want memories?!! There were no stinking memories . . . you had to remember what frequencies you wanted or at least what portions of the bands you wanted to tune. The memories were between your ears.
But it was a receiver with an extraordinarily low noise floor, and many a happy evening I enjoyed programming from half a world away. Drifting off to sleep with headphones piping in a signal from a distant land was not without its dangers, though. One night I fell asleep listening to the news from Radio Australia beamed, in English, to Papua, New Guinea. I woke a while later to the same newscast beamed to Papua, New Guinea, but this time in Pidgin English. I heard some English words, but the rest did not make sense. I panicked, thinking some neurologic event had scrambled my brain, but a crisp voice rescued me: “This has been the news in Pidgin English, from Radio Australia.” Thank God!
When Passport ceased publication, I neglected shortwave radio for over a decade, busy with freelance writing and running the Commuter Assistance Net on two meter ham radio.
Earlier this year, the SWLing bug bit me again, and I fired up a long-neglected Grundig Satellit 800 and started cruising around the HF frequencies. Many of the big-gun shortwave stations were gone, or they weren’t aiming programming at North America, but there was plenty to listen to, including shortwave stations, HF ham bands, and some utility stations.
Gee, I thought, it might be great to have a radio for a little horizontal in-bed DXing before shutting off the lights for the night . . . something I could hold in my lap, turn the tuning knob, and discover hidden treasures. The Satellit 800, emphatically, was not the answer. It is a large radio, roughly the size of the vaunted Zenith Transoceanic radios, and definitely not suited for laps.
So, based on a great reputation and excellent reviews, I bought a CCrane Skywave SSB. The Skywave SSB is a powerhouse, offering AM, FM, Weather, Air, SW, and SSB in a package roughly the size of a deck of cards and perhaps twice as thick. And it delivers the goods, offering worthy performance on every band, although SW performance is greatly enhanced by attaching the wire antenna that is included with the Skywave SSB.
Two factors, I discovered, reduced the suitability of the Skywave SSB for bedside DXing. First, the tuning knob is really small, so you can’t just twirl your finger to traverse the bands. It also has click-detents on the tuning knob and muting between tuning steps, so the tuning is non-continuous, which diminishes the pleasure for me. So the drill becomes: use the automatic tuning system (ATS) to search the bands and store stations in memory and then use the keypad buttons to jump from stored station to stored station. Further, each keypad key makes a distinct “click” sound when properly depressed. And that brings us to the second factor: one night, I am attempting to explore the stations stored by the ATS when my bride, who was trying to doze off, taps me. “What?” I say. “Too much clicky-clicky,” she says. Oh, I thought; now I need to find a radio that is quiet, so long as I am wearing headphones.
Now, just to be clear: I would highly recommend the CCrane Skywave SSB (except for use next to a spouse who is attempting to sleep), particularly for traveling because it is so small and performs so well. To underscore the value of a shortwave-capable travel radio, some years ago, I spoke with a journalist who was in Russia when the Chernobyl nuclear disaster took place. Russian media were not reporting on it at all; he found out about Chernobyl by listening to the BBC on a shortwave radio he had tucked into his luggage, and he rapidly made plans to leave Russia.
A bunch of research eventually led me to the Tecsun PL-880, which is about the size of a trade paperback book. According to some reviewers (including Dan Robinson), the 880 is a bit more sensitive and shortwave than the PL-990. The 880 offers a bunch of bandwidths on both AM and SSB, and the tuning is butter smooth with no muting or detents. The smallish tuning knob has a bit of knurling on the edge, which make it possible to twirl the knob with one finger; you can fine-tune SSB with another knob, and, with one button-press, use the tuning knob to select filter bandwidths or memory channels. In short, if you avoid the keypad, this is a radio that can be operated in near silence next to a better half who wishes to snooze.
The performance, so far, is exemplary; using the PL-880 whip antenna, I could readily hear Gander, Newfoundland, broadcasting aeronautical weather as well as Shannon, Ireland, air traffic controllers directing aircraft crossing the Atlantic Ocean. Yes! I haven’t yet begun to explore all that the PL-880 can do, but it promises to be a lot of fun.
Many thanks to SWLing Post contributor, Dan Robinson, for the following guest post:
by Dan Robinson
It’s been a few weeks since my last commentary on the Malahit/Malachite, which as of this writing remains at the DSP-2 level, though there are continuing hints from the Malahiteam in Russia about future changes, including a DDC version.
All of the observations I made in previous articles are unchanged. As of today in mid-September, the latest test firmware version posted by the Malahiteam remains M2_FW2_10D. This includes a widening of the waterfall bandwidth from 160 kHz to 192 kHz. See my previous articles for more information.
Recently, I obtained a Chinese clone, one which will be familiar to anyone who has taken a dive into the clone market. This one is by HFDY and is immediately recognizable for its front speaker and longer slim rectangular form factor.
The HFDY (Malahit SDR V 3) has two high quality black metal encoder knobs on the right, with a large power button between, and USB-C and a headphone jack on the left side. On the bottom are two OFF/ON slide switches, one marked for 3.3 volts and the other BOOT(O).