China Radio International’s overwhelming AM bandwidth via Havana

Scott-Marine-SLR-M-Dial

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:

China-Radio-International-Bandwidth

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.

Okay–sorry about the rant!

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26 thoughts on “China Radio International’s overwhelming AM bandwidth via Havana

  1. Omar

    Hello! I’ve been listening to Chinese radio CRI in short wave in different bandwidths and it sounds wonderful, but does anyone know which processor they use? since it sounds with a rich effect in harmonics and a special brightness as if it were FM, and with different bandwidths the effect is maintained !!

    Reply
  2. Sean

    I too have noticed a seeming increase in bandwidth for RHC and can no longer comfortably listen to it using my Icom IC-R20 portable receiver as I’m only able to utilize about 6kHz of the signal making it sound awful these days. Too bad they don’t seem interested in sticking to conventions because they are missing out on their propaganda possibilities by making their signal on 6,000 kHz unbearable to listen to. I thought my little R20 was in need of a trip to Icom for repair until I realized they were just being bad broadcasters. Too bad for them really. I have run across several broadcasts up to 11kHz wide. So sad. Even my venerable Icom IC-R71A is unable to cope with the excessive width.

    Sean,
    KB8JNE

    Reply
    1. DL4NO

      Sean,

      what you forget is our special view of SW as a DX medium.

      About any broadcaster thinks of target areas. If their programming can be easily heard there, everything is OK for them. So if RCI “self-interferes” with transmitters in Cuba and Albania it does not matter to them.

      But obviously it is a pity that they wipe out Radio Australia for you. But even they will not complain as their target area is not the Americas.

      Reply
  3. Baz

    When conditions are right, and the right music is played, you’d be hard pressed to tell it from FM – they sound that good. With so few transmissions on SW nowadays, the band can afford more of these. I activily look for these broadcasts. They often sound amazing.

    Reply
  4. 13dka

    OK since I got a shortwave-capable SDR today I had an opportunity to hear (and see) them now on 9,600kHz (and also on 41 and 25m) with full 32kHz bandwidth, it boggles the mind…

    BUT: I turned up receiver bandwidth accordingly, employed a grain or three of audio noise reduction (which usually makes the signal sound a bit like it came via Skype) on that signal and I went like “wow, this is shortwave 2010 style” – sounding crisp like an FM station (in fact they were relaying an English program from “E-Z FM”), no noise, only the occasional hint of selective fading and regular fading gave away that this is actually an analog shortwave broadcast (shouldn’t that be “widecast”?) – too bad I didn’t care much about the programming, it was some annoying variety talk show about family issues and so on.

    Anyway, my point is, this could be actually pretty enjoyable, what if R. Australia would come in with a sound like this, in a quality that even the missus wouldn’t mind if that would be playing during breakfast? 🙂

    Reply
    1. DL4NO

      In my comment (second from top) I reference a page in my Web site. There I write about the same as you: While most stations leave die AM-modulated domain, others see this as a chance.

      For example Romania operates medium-wave stations with quite extensive bandwidths. At night they are about the loudest here in southern Germany.

      Romania has 2/3 the area of Germany and only 1/4 of our population. Considering the Carpatian Mountains you can imagine why FM is no alternative for them.

      Reply
  5. Mattc

    I’ve frequently listened to Radio Australia during the early morning hours on 9,580 kHz often you can here CRI in the background using my SONY ICF-SW77. Oddly enough yesterday during the afternoon for the first time i can remember I picked up part of the 9580 broadcast around 20:00 UTC usually it fades out at 15:00 UTC and thats the last I hear of it until the next broadcast.

    Reply
  6. 13dka

    I witnessed that too, although it was on 41m and they used only modest 12 kHz. Of course this is bad for several obvious reasons, but then again I can imagine how compelling it might be to experiment with big bandwidth that fits crappy wide filters in small Chinese radios just fine (any decent radio except SDRs won’t be able to benefit from that after all). Hi-fi shortwave! Screw international plans and agreements, screw other users of the band and screw better suited technology, let’s just blow it out loud and wide!

    It’s not like today’s somewhat abandoned SW bands wouldn’t allow for such experiments, it would just be nice if RCI would generally coordinate their transmissions with the rest of the crowd, in particular if they want to occupy larger portions of the band.

    Reply
  7. Tom Servo

    I’ve written both RHC and Arnie directly about their transmitter issues (as well as those of Progreso on 4765) and never heard back from either inquiry. I just don’t think they care. And I truly believe this issue lies squarely with Havana, not CRI.

    It isn’t just Radio Australia that they’re bleeding over, either. In the evenings, CRI actually self-interferes because they’re on 9570 from Cerrik and 9580 from Havana at the same time for a while. And the Havana broadcast often spills over onto the Cerrik broadcast. The audio and clarity from the Cerrik transmitter is much better, and I’d rather listen to it than Havana any day, but due to the splatter it is often difficult to hear either of them clearly.

    Reply
  8. TP Reitzel

    Finally, someone else who agrees with me about RHC and CRI. RHC and CRI can produce a nice sounding broadcast IF they choose to do so, but normally the distorted sound is a consequence of an over modulated, wide band signal. I can’t generally listen to RHC for more than a few moments at a time without driving me to grind my teeth. Lastly, Arnaldo, your biased opinion of DRM is just baseless nuttiness if correct configurations are used on shortwave.

    Reply
  9. Edward

    I notice that window that looks like a spectrum analyzer to me. What is that? Is this one of those USB dongles and a software package? Who makes it?

    Reply
    1. CraiginMKE

      The software is free, just look up SDR software, the really inexpensive dongles will not go low enough to tune in the lower bands. The better ones do a converter option that will allow the full HF band.
      I just begun to play around with both types of dongles
      Youtube has many video tutorials that can get you going.
      Look for one that has two antenna inputs, I think many will agree that that is the better way to go?

      Reply
    2. DL4NO

      These are screenshots from SDR radios, i.e. a relatively simple RF frontend with AD converters, and a program to further process the input signal. What you quite rightly identify as “spectrum analyzer” is created on a standard PC or tablet computer using “fast fourier transformation” (FFT).

      Your “USB dongles” for DVB-T normally cannot receive below 40 or 50 MHz. Either they use a 40 MHz up converter like the DX Patrol does, Or they use a different chipset like SDRplay does.

      Reply
  10. Lawrence Harris

    In contrast to my BBC comment!

    Maybe they are sequencing their broadcasts at different locations around the globe – now we have no 1440 kHz in Europe, so maybe they’ll move on to annoy someone else soon!

    Reply
  11. DanH

    1200 UTC… you have got to be kidding. I listened to Beijing Hour on 9790 kHz at 0330, 1-28-2016 UTC. This one one of the strongest signals I have ever received on 31 meters. It was 55445 with the RF gain on the 909X turned all the way down. This signal was supposedly from “Havana” and had the typical low freq Cuban audio hum signature. I don’t have a waterfall display, but I have ears.

    Reply
  12. Broadwing

    First of all, that’s a gorgeous rig. Secondary to that is CRI and RHC don’t care. China should be banned from the airwaves until they stop their jamming activities of VOA, RFA, BBC, and any other station they purposely jam hourly and daily. I know that won’t happen but there should be a meaningful way they are sanctioned.

    For me that’s more abusive than your issue this morning, not to say it’s not important, just this behavior goes on all the time, plus China broadcasts numerous programs to other countries. Their broadcasts are never interfered with.

    A while back, I asked the CRI English section what was their Governments’ justification for jamming SW broadcasts to China, and the reply I received was that I was rude for asking, and it would be inappropriate for them to answer. It figures. I guess culturally it’s acceptable for them to be disrespectful to other countries. Plus you never hear to much flak given to them about their jamming activities.

    They have a very slick communications set up and Internet interface for us to use and they enjoy trying to show only the best of China to the outside world. It is too bad the average Chinese citizen in China has no access to outside communications or opinions that do not tow the Party line. This is a country we need to watch very, very, closely. They are a real threat.

    Reply
  13. robert

    I live in southwest missouri,yes they kill austraila but my radio recieves them clear,sometimes i narrow band width up too.they come in here like a blow torch,can get them on the stick easy not using my long wire

    Reply
  14. Al Holt

    To my ears CRI relayed by RHC sounds distorted and over modulated making their entertaining “morning” program “China Drive” unbearably hard to listen to. With a (mostly) all talk format, the wide bandwidth makes no sense. I’ve written to them about it; the reply I got from the “PR department” was they had no control over it.

    Reply
    1. Thomas Post author

      Yes, Al–you’re spot-on! In fact, the same can be said of many of RHC’s own programs. They’re often distorted and over-modulated.

      Reply
  15. DL4NO

    As I see it RCI is the most aggressive user of excessive bandwidth. Here in Germany I can hear an AM station from Rumania that does about the same, see http://www.dl4no.de/thema/derlangs.htm at the bottom.

    My technical question about this AM station is how they get enough bandwidth from their antenna. Their bandwidth is more than 1% of center frequency. I know of a DRM test on medium wave here in Germany. They had to order a specially designed matching network as their transistorized PA complained about a bad SWR over the +/- 4.5 kHz bandwidth. A perfect match at the center frequency was not enough.

    Reply

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