R. Nacional de Amazonia Problem

GB46

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Has anyone listened to R. Nacional de Amazonia on 11780 kHz lately? Their audio is no longer as clear as it usually was. Now it's quite distorted. I thought the problem was with my radio, until I noticed that their audio was just as bad on another radio. I couldn't check them on their alternate frequency of 6180, as they aren't coming in there at all now.
 

MDScanFan

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I caught them before they signed off on 11780 and I do hear the distortion. My reception on 6180 is not as strong so I can’t say for certain but I don’t notice any distortion.
 

GB46

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Thanks; at least the distortion isn't just on my end. As for signal strength, they used to come booming in here on both frequencies, but now even their 11780 kHz signal is weaker than usual. That may be due to band conditions, of course.
 

ka3jjz

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There has been numerous reports of RNA having transmitter issues and distortion on the WoR (World of Radio) reflector....Mike
 

n5rv

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I was listening to them earlier today and they were back to their fine quality audio. I could listen to their music programming all day.
 

GB46

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Yes, they were doing fine yesterday. They're one of my two favorite SW stations for music. The other one is the Voice of Greece, at least when their signal is strong enough here. Even then, however, the music can be hard to make out due to rapid fading.

That's when I go to the internet and listen to streaming audio from one of Greece's local FM stations. Lots of good music there, although my favorite, Glenti FM, seems to have discontinued their streaming recently, because my media player can no longer connect to their URL, and the "listen live" link on their website doesn't work, either.
 

MDScanFan

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In another thread I saw you mention that you live in an apartment that has stucco lined with metal mesh (roof is unlined) and use and inside antenna. And you can still receive R. Nacional de Amazonia from BC reliably? I’m impressed. What kind of antenna are you using? Do you employ any active RFI mitigation?

Yes, they were doing fine yesterday. They're one of my two favorite SW stations for music. The other one is the Voice of Greece, at least when their signal is strong enough here. Even then, however, the music can be hard to make out due to rapid fading.

That's when I go to the internet and listen to streaming audio from one of Greece's local FM stations. Lots of good music there, although my favorite, Glenti FM, seems to have discontinued their streaming recently, because my media player can no longer connect to their URL, and the "listen live" link on their website doesn't work, either.
 

GB46

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In another thread I saw you mention that you live in an apartment that has stucco lined with metal mesh (roof is unlined) and use and inside antenna. And you can still receive R. Nacional de Amazonia from BC reliably? I’m impressed. What kind of antenna are you using? Do you employ any active RFI mitigation?
Well, this is may surprise you: I receive RNA well on any of my three SW radios, two of which are portables using only the whip antennas. If I connect the 23-ft. wire antenna that came with my Sangean ATS-909x portable to the radio's input jack, the signal strength is only slightly better, but the noise increases significantly, so there is no appreciable advantage. The other portable is an old Sony ICF-2002 bought in 1998.

The third SW radio is an Icom R75 tabletop from 1998 requiring an external antenna, for which I use the same 23 ft. of wire. The portables actually sound better than the R75, which has the strange characteristic of making the noise a lot more noticeable. Even the noise reduction feature added by the R75's DSP module accomplishes next to nothing, and setting the NR level too high causes distortion.

By the way, I can sometimes hear RNA on my portable scanner, as its wide frequency range includes the HF bands. Again, this is with just the whip, which is nothing more than a little "rubber duck" antenna. So that makes four radios altogether. I am currently only using the Sangean for shortwave; I bought the scanner for VHF and UHF monitoring. The other radios are now in retirement.

As for RFI mitigation, none of that works in this building. I'm surrounded on all sides by sources, including lots of power lines outside.
 

MDScanFan

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That’s very interesting that you are able to get that reception indoors with portables. Very cool.

With my desktops I have good luck with mitigating indoor RFI with the ANC-4. For instance, with an indoor amplified loop antenna and a nearby vertical probe for noise pickup. This may be worth a try if you have not done so already. For scanning the bands it is not convenient - needs to be retuned across frequency. But if you are trying to listen to a particular frequency it may help null out the noise.
 

GB46

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Correction: That Sony 2002 was bought in 1986.

Yes, a loop antenna would be directional and null out some noise, but after going around from room to room with a portable using the internal loop on the AM band, I can see that directionality wouldn't help, because various RFI sources show up in all directions. SWLing in a city is already problematic, without also living in an apartment building full of neighbors with TVs, etc. I even have to put this laptop into sleep mode if I want to monitor the AM broadcast band, otherwise it blanks out the entire band.
 
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