Each morning, I enjoy listening to Radio Australia on 9,580 kHz, but I’m forced to tune elsewhere due to interference when China Radio International starts broadcasting on 9,570 kHz, via Radio Havana Cuba’s relay.
Hypothetically I should be able to mitigate any adjacent interference from CRI by listening to Radio Australia’s upper sideband. But unfortunately, RHC’s transmitters spew spurious emissions a full 20 kHz on either side of their carrier. It’s most annoying.
Here’s what my waterfall looked like when CRI signed off:
Notice how clear the 35 kHz waterfall window became (that’s Radio Australia centered on 9850 kHz):
The reason for this is clear: obviously, some of RHC’s transmitters are in need of care–and they’re not the only ones.
I’ve received a number of requests from Radio Cairo to post notices about their English language broadcasts. Normally, I’m quite happy to post press releases, but in each case I’ve mentioned that their English broadcasts are almost impossible to understand. For years, RC has had a problem with AM modulation (I assume) and, to my knowledge, have never addressed it.
I’ve sent RC feedback on a number of occasions; in response, I’ve received only the inconclusive reply that they’re “looking into the situation.”
To underscore the point, on Sunday Andrea Borgnino shared the following video/audio of Radio Cairo via Twitter.
There are other broadcasters that emit messy signals, but Radio Havana Cuba and Radio Cairo are the most noticeable in my listening area. And, it seems, neither broadcaster is in any hurry to address their ongoing problems.
In Radio Cairo’s case, especially, the broadcaster is simply wasting money by attempting to broadcast a signal that can neither be received nor interpreted. It’s rather sad. Ultimately, one has to wonder why they bother to broadcast at all…
Radio Havana Cuba, China Radio International, and Radio Cairo (among others) take note: a little care of your radio transmitters will go a long way toward increasing your listenership.
What you can do: Consider contacting broadcasters when when you become aware of transmitter problems. Despite RC’s notable exception, oftentimes a broadcaster may not be fully aware of the issue––thus your feedback is necessary to help correct the problem.
This morning, I listened to Radio Australia on 9,580 kHz with my WWII era Scott Marine Radio SLR-M (above).
Radio Australia provides a reliable, strong signal into North America every morning and it’s where I typically tune for the morning news at the top of the hour.
China Radio International also fires up on the adjacent frequency of 9570 kHz around 1200 UTC–their signal is also incredibly strong here as it’s relayed from Radio Havana Cuba at 250 kW. CRI’s bandwidth is almost always wider than 10 kHz–indeed, it’s often 20 kHz–which means that it completely wipes out any average adjacent signal.
Indeed, when I’m testing selectivity on portable shortwave radios, I’ll often tune to Radio Australia and wait for CRI to fire up on 9570 kHz. If the portable radio can still lock onto Radio Australia after CRI is on the air–or, better yet, if an upper side band sync lock can eliminate all traces of CRI–I know the receiver has decent selectivity.
This morning, when CRI began transmitting at 1200 UTC, their signal completely wiped out every trace of Radio Australia. Though the SLR-M’s narrow AM filter is still quite wide, it can typically cope with the adjacent CRI carrier.
I fired up the TitanSDR to see what CRI’s signal looked like on a spectrum display–here’s what I found:
CRI’s AM bandwidth was 30+ kHz wide!
In my book, that was an abusive use of the band.
This was, by no means, an isolated event. It was just particularly annoying for me this morning as I was enjoying a good cup of coffee and the morning ABC news.
I’ll send a message to CRI and RHC about this, but I have my doubts anyone will take action.
Cuban President Raul Castro is urging the U.S. government to stop radio and television broadcasts that Cuba considers harmful, while also saying that his government is willing to keep improving relations with the United States.
In a speech broadcast on state television Friday, Castro said that his government will “continue insisting that to reach normalized relations, it is imperative that the United States government eliminate all of these policies from the past.”
He noted that the U.S. government continues to broadcast to Cuba, including transmissions of Radio Marti and TV Marti, despite Cuba’s objections. Radio Marti and TV Marti are overseen by the Broadcasting Board of Governors, which is also the parent organization of the Voice of America.
Castro also criticized U.S. immigration policy that allows Cuban migrants to live in the United States if they reach U.S. territory.
“A preferential migration policy continues to be applied to Cuban citizens, which is evidenced by the enforcement of the wet foot/dry foot policy, the Medical Professional Parole Program and the Cuban Adjustment Act, which encourage an illegal, unsafe, disorderly and irregular migration, foment human smuggling and other related crimes, and create problems to other countries,” Castro said.
Many thanks to SWLing Post contributor, London Shortwave, who has posted an article on his blog regarding US/Cuba relations after Presidents Barack Obama and Raul Castro announced, last Tuesday, the re-establishment of relations. London Shortwave has included recordings from the VOA, Radio Marti and Radio Havana Cuba.
If you live in the Americas and you regularly listen to a shortwave radio, you have no doubt heard Radio Havana Cuba across the shortwave spectrum. When I travel in North or Central America, I can easily hear RHC, often without even extending the telescopic antenna on my portable.
A long-running program on RHC’s English hour is Arnie Coro’s DXers Unlimited.
Tuesday night, I recorded the DXers Unlimited segment from RHC’s The English Hour on 6 MHz, and offer it here for your listening pleasure. If the recording doesn’t sound typical of shortwave radio, it’s because: a) RHC’s signal is exceptionally strong into North America, and b) I recorded this with an AM filter 24 kHz wide. In other words, I widened my DSP filter to match RHC’s bandwidth on my spectrum display–and to put this in perspective, I regularly record between 7-9 kHz wide. (This results in the crisp, high-fidelity audio you hear in this recording, though unfortunately at the compromise of any adjacent stations abiding by HF broadcasting etiquette.)
Screenshot of digital mode being selected in FLDIGI. Click image to enlarge.
SWLing Post readers have seen previous posts regarding text being broadcast via shortwave digital modes on WBCQ, WRMI and The Mighty KBC (which broadcasts again this weekend).
Recently, Kim Elliott explained his mission behind these digital tests. Not only do I agree, but I support him completely. Why? It’s proof that the shortwave spectrum is an excellent medium to transmit digital information across the globe. Decoding requires a very basic shortwave radio, some free software and a computer. I believe, in the near future, there will be a smart phone app that can handle this with ease–it simply needs a developer (hint, hint).
Here is Kim Elliott’s post on the topic–I have emphasized points in bold:
Radio amateurs use several modes to transmit text via shortwave. It occurred to me that text via shortwave might be a workaround whe[r]e the internet is not available because of disasters, dictators, or other causes.
I have not yet convinced any major international broadcasters to let me test this hypothesis on their (remaining) shortwave transmitters. However, the Netherlands-based Mighty KBC has kindly been allowing me two one-minute segments during their broadcast to North America at 0000 to 0200 UTC on 9450 kHz. This is via leased time on a transmitter in Bulgaria.
Reception of text via shortwave is possible on an inexpensive shortwave radio, even one without single sideband (SSB) capability. The audio is patched into a PC that does not have to be especially powerful. This involves a patch cord from the earphone jack of the radio to the microphone input of the PC. If there is no patch cord, placing the radio’s speaker near the built-in microphone of a laptop might work.
Software for decoding the text should be installed in the PC. There are several available to radio amateurs, including DM780, MixW, and MultiPSK. Especially popular these days is Fldigi. This is available from www.w1hkj.com. While you are there, please also download Flmsg, because it will be needed for this weekend’s test on KBC. [Note: This software is free and open source.]
This weekend’s test on KBC will feature the MT63 modes with long interleave. After Fldigi is installed, go to Configure > Modems > MT-63 > check 64-bit (long) interleave, 8-bit extended characters, and Allow manual tuning. Also, go to Configure > Misc > NBEMS > check Open with flmsg and Open in browser and, below that, indicate where your flmsg.exe file is located.
The first KBC text transmission will be around 0130 UTC Sunday (Saturday evening 8:30 pm EST). The MT63-1000 mode with long interleave will be centered at 1000 Hz on the waterfall visible on the software display. PSKR125 will be cenetered at 2200 Hz. Decode one while listening, and decode the other from your recording of the transmission.
The second text transmission will be just before 0200 UTC Sunday (9 pm Saturday EST). This will be MT63-2000 centered at 1500 Hz. This message will be formatted for Flmsg. If all goes well, the shortwave transmitter in Bulgaria will open a new window of Flmsg and then open a new window of your web browser with formatted content, in color no less.
One week after my first text transmissions (11 November) on KBC, Arnie Coro at Radio Havana Cuba began transmitting digital text modes on his Dxers Unlimited program (in English). He might do so again this weekend. The schedule for DXers Unlimited can be found at the World of Radio website (where all times and days are UTC, so those UT Monday transmissions are actually Sunday evening in North America).