Shortwave listening and everything radio including reviews, broadcasting, ham radio, field operation, DXing, maker kits, travel, emergency gear, events, and more
Despite dismal propagation, I was quite happy to receive a relatively strong signal earlier this week (31 August 2015) from Channel Africa, starting around 16:40 UTC on 15,235 kHz.
This recording begins with the French language service (already in progress), followed by the English language service. Receiver used was a WinRadio Excalibur connected to a large horizontal delta loop antenna.
The Mighty KBC will be making their seasonal move to 7,375 kHz on Sunday September 6, 00:00 – 03:00 UTC.
The Mighty KBC’s Giant Jukebox is an easy catch for listeners in much of North America and Europe–if you’ve never heard the show, you’re certainly in for a treat.
The lighter shaded side of the AM carrier indicates a lower sideband sync lock. (Click to enlarge)
A few days ago, I tuned to 9,420 kHz and found a relatively strong signal from the Avlis transmitter site of the Voice of Greece. The broadcast was quite clear until a heterodyne (het) tone popped up out of nowhere.
I checked the spectrum display of my Excalibur to find two steady carriers located about .5 kHz off each side of VOG’s AM carrier. I assume this may have been a faint digital signal centered on the same frequency as VOG.
The noise was annoying, but SDRs (and many tabletop radios) have tools to help mitigate this type of noise.
The het tone was originating from both sidebands of the VOG AM carrier (see spectrum display above). I had planned to use my notch filter to eliminate the noise, but I had two carriers to notch out and only one notch filter.
Synchronous detection to the rescue…
The simple solution was to eliminate one of the carriers using my SDR’s synchronous detector which can lock to either the upper or lower sideband. In this case, it didn’t make any difference which sideband I locked to because both had similar audio fidelity and were otherwise noise free. In the end, I locked to the lower sideband, thus eliminating the het in the upper sideband.
Next, I enabled my notch filter and moved its frequency to cover the annoying het carrier in the lower sideband; I kept the notch filter width as narrow as I could to preserve VOG’s audio fidelity. You can see the notch filter location and width in the spectrum display above (the notch filter is the thin yellow line).
I should note here that the great thing about using an SDR–or tabletop receiver with a spectrum display–is that you can see where the noise is. I was using my WinRadio Excalibur, but pretty much any SDR in my shack could have handled this task.
The results? No het tone and I was able to preserve the great audio fidelity from the Voice of Greece broadcast!
Here’s a 3.5 hour recording I made after cleaning up the signal. I believe at one point in the recording, I switched off the notch filter to demonstrate how loud the het tone was:
Icom introduced a new general coverage transceiver this year at the Tokyo Hamfair: the Icom IC-7300.
Icom has released a preliminary spec sheet (click here to download), but no pricing information yet. The IC-7300 will most likely be the least expensive Icom transceiver with a full spectrum display.
At first glance, I like the form factor and touch screen display–the panel appears to be less cluttered than many other large-display models. The ‘7300 has dedicated knobs for passband tuning and AF/RF gain (major plus in my book). It also comes with a built-in automatic antenna tuner.
I’ll post more info once Icom releases pricing and availability.
Many thanks to SWLing Post reader, Paul Walker, who writes:
I am a radio personality here in the USA as well as a SW and MW DX’er.
I appeared on the 11092.5 USB during Radio Saint Helena Day 2009 and have several short recordings, which are attached. That’s my voice doing the station identification/promotional announcements.
Sample 1
Sample 2
Very cool, Paul! It’s quite amazing to hear studio quality audio from Radio St. Helena Day as so many of us had to strain to hear their signal from across the Atlantic! Glad you were able to be a part of such an amazing little station.
I miss those Radio St. Helena Days and, though I know it’s doubtful, certainly hope the station considers firing up a shortwave transmitter again.
Many thanks to SWLing Post and Shortwave Radio Audio Archive contributor, Brian Smith, for the following guest post and vintage recording:
Shortwave Radio 1974: Canada, Argentina, Spain, West Germany, Albania, utility stations
-Brian Smith (W9IND)
Want to know what shortwave radio sounded like in 1974? This 55-minute recording, recovered from a cassette, was never intended to be anything but “audio notes”: I was an 18-year-old shortwave listener who collected QSL cards from international stations, and I was tired of using a pen and a notepad to copy down details of the broadcasts. I wanted an easier way to record what I heard, and my cassette tape recorder seemed like the perfect means to accomplish that goal.
But it wasn’t. I soon discovered that it was simpler to just edit my notes as I was jotting them down — not spend time on endless searches for specific information located all over on the tape. To make a long story shorter, I abandoned my “audio notes” plan after a single shortwave recording: This one.
Hallicrafters S-108 (Image source: DXing.com)
Still, for those who want to experience the feel of sitting at a shortwave radio in the mid-1970s and slowly spinning the dial, this tape delivers. Nothing great in terms of sound quality; I was using a Hallicrafters S-108 that was outdated even at the time. And my recording “technique” involved placing the cassette microphone next to the radio speaker.
Thus, what you’ll hear is a grab bag of randomness: Major shortwave broadcasting stations from Canada, Argentina, Spain, Germany and Albania; maritime CW and other utility stations; and even a one-sided conversation involving a mobile phone, apparently located at sea. There are lengthy (even boring) programs, theme songs and interval signals, and brief IDs, one in Morse code from an Italian Navy station and another from a Department of Energy station used to track shipments of nuclear materials. And I can’t even identify the station behind every recording, including several Spanish broadcasts (I don’t speak the language) and an interview in English with a UFO book author.
The following is a guide, with approximate Windows Media Player starting times, of the signals on this recording. (Incidentally, the CBC recording was from July 11, 1974 — a date I deduced by researching the Major League Baseball scores of the previous day.)
Guide To The Recording
00:00 — CBC (Radio Canada) Northern and Armed Forces Service: News and sports. 07:51 — RAE (Radio Argentina): Sign-off with closing theme 09:14 — Department of Energy station in Belton, Missouri: “This is KRF-265 clear.” 09:17 — Interval signal: Radio Spain. 09:40 — New York Radio, WSY-70 (aviation weather broadcast) 10:22 — Unidentified station (Spanish?): Music. 10:51— Unidentified station (English): Historic drama with mention of Vice President John Adams, plus bell-heavy closing theme. 14:12 — Unidentified station (Spanish?): Male announcer, poor signal strength. 14:20 — Unidentified station (Spanish): Theme music and apparent ID, good signal strength. 15:16 — Unidentified station (foreign-speaking, possibly Spanish): Song, “Chirpy Chirpy Cheep Cheep.” 17:00 — Deutsche Welle (The Voice of West Germany): Announcement of frequencies, theme song. 17:39 — Unidentified station (English): Interview with the Rev. Barry Downing, author of “The Bible and Flying Saucers.” 24:36 — One side of mobile telephone conversation in SSB, possibly from maritime location. 30:37 — Radio Tirana (Albania): Lengthy economic and geopolitical talk (female announcer); bad audio. Theme and ID at 36:23, sign-off at 55:03. 55:11 — Italian Navy, Rome: “VVV IDR3 (and long tone)” in Morse code.
Brian, this is a brilliant recording–regardless of audio quality–and we’re very thankful you took the time to share it. Propagation has left something to be desired as of late, so time traveling back to 1974 has been incredibly fun.
Post Readers: If, like Brian, you have off-air recordings on tape that you’d like to share, please contact me! Even if you don’t have the means to transfer your tapes to a digital format, I’m a part of a small community of shortwave radio archivists who would be quite willing to help.
Please support this website by adding us to your whitelist in your ad blocker. Ads are what helps us bring you premium content! Thank you!
Despite dismal propagation, I was quite happy to receive a relatively strong signal earlier this week (31 August 2015) from Channel Africa, starting around 16:40 UTC on 15,235 kHz.
