mike.chambers

Antenna Getting Better

Well, I am slowly but surely making progress with my antenna. I have been having a lot of trouble with RF interference from my random wire antenna. I ran a shielded COAX feed to it, which I grounded, but reception was horrible.

Well, this weekend, I went back up the hill, and made some modifications to try and get a better ground. I also grounded the end of the COAX going into the radio. This second step seemed to make a noticeable improvement to the signal quality (although there is still a lot of interference). I was able to pick up some broadcasts I hadn't picked up before:

• 11735 kHz 0118 - 0122 UTC (Jan 14, 2007). Voice of Korea. SIO 222. This is the first time I have picked it up this early in the night
• 9675 kHz 0456 - 0505 UTC Radio Exterior de Espana. SIO 433. (via Costa Rica). News in Spanish.

My next step is to try to get a copper bar for the antenna ground (just have a small metal nail right now), as well as use a balum (need to read up on these some more).

Too much interference? Get in the car

Well, I have been pretty frustrated for the past week or so, as I have realized that there is just too much RF and electrical interference in my house. It is making shortwave listening difficult. Some of the interference is from my house (electrical system is really noisy), and some is from the neighbors.

As I posted earlier, I put up a long wire antenna, and this drastically improved my signal strength. However, it lead to two problems. First, the increased antenna power is overloading my receiver, and I am receiving AM stations all through the shortwave bands. Second, the antenna I currently have up comes directly into the house, and thus picks up all of the RF noise from the house. I put up a test antenna that comes into the house via a shielded cable, but reception was very bad with a lot of noise (I am guessing I did something wrong).

Anyways, I have been pretty frustrated, so I decided to hop in the car, and head up to the top of the hill (Walter Hass Park which overlooks San Francisco) to see if it was my location, or maybe all shortwave reception is bad. I planned on just checking for 5 minutes, but ended up staying over an hour because the reception was so good.

Here is what I picked up (January 11, 2007 UTC):

• 0653 Khz (probably should be 6055 but lots of interference from Radio Havana at 6060) 0617 UTC - 0629 UTC : SIO 433 : French language. Mention the Congo. News, Bush / Putin / Irag, and sports scores. I think I caught a BBC mention, and the frequency charts say this is BBC (which would be my first BBC hit since I started back in shortwave). Broadcast from Ascension Islands
• 6080 Khz : 0633 - 0636 : VOA News. Very strong signal. Originated from Sao Tome, which mean this was my first African reception.
• 6120 Khz : 0636 UTC - 0642 UTC : SIO : 555 : China Radio International, Voices from Other Lands program with Roy Kiehe. Discussion with an author of a book on the Balkans.
• 9580 Khz : 0650 UTC : SIO 232 : Very faint music. Sound Africa, and I think I also picked up some French. This was a very weak signal, and the only reason I am posting because according to the schedules, it might have been a broadcast from Gabon.
• 9765 Khz 0655 - 0700 UTC : Strong Signal. Radio New Zealand. Playing some music.

I would have actually stayed much longer, but 1) I was freezing. It was about 40 degrees F, and I was in shorts and slippers, and 2), I half expected the cops to come by and check out what I was doing in a car with a long wire hanging out, occasionally blinking a Flash light (which I needed to take notes).

It was a ton of fun though, and reminded me how much fun the shortwave can be. I am still going to try to figure out how to fix some of the noise issues at my house, and am planning some shortwave camping trips.

Clip of Cuban Jamming of Radio Marti

I have had really good reception tonight, and scanning around I came across a Radio Marti broadcast being jammed by Cuba (I am assuming it is Cuban). First, the details:

Radio Marti :0738 UTC - 0745 UTC, 6030 Khz. SIO 312. Male and Female have a conversation in Spanish. Jamming being broadcast over program (sounds like running water / brook).

Checking Passport to World Band Radio, it confirms Radio Marti at that time and frequency, and that the broadcast is jammed.

Listen to sample of Radio Marti Broadcast being Jammed

The jamming is not as clear on the recording, but you can hear it. It sounds like a babbling brook being broadcast over the Radio Marti broadcast.

You can find another report / example of the jamming here, and an analysis of the jamming here.

More information on Radio Marti at wikipedia.

Chinese Jamming Reception of Radio Free Asia Broadcasts

As I mentioned the other day, I have been receiving what I believe to be a grayline propagation broadcast of Radio Free Asia (RFA) programing to the Uyghur region of China from Tajikistan every evening around dusk. However, I had not been able to positively ID it, as the programing was just music.

Well, I spent quite a bit of time researching this to try to confirm the original. I download Uyghur music to see if it sounded similar to the music programing I was getting (it did), I searched for and listened to the RFA Uyghur broadcasts to see if they matched (they didn't), and I contacted Radio Free Asia to ask them about their Uyghur programing.

In particular, I asked RFA if their Uyghur included any musical programing, or if it was just news (all I could find on their website was news archives). They responded very quickly that they only program news in their Uyghur broadcasts . When I replied to thank them, and mentioned that I was receiving musical programing on that frequency, they responded that I was most likely picking up the Chinese jamming the signal (they have a new jamming station in Kashgar), to block the RFA broadcasts into the Uyghur region.

Once they mentioned that, it made sense. I had noticed the night before that the musical programing was the same every day. The programing was also just an hour of music, with no news or station identification.. It looks like the Chinese just play the same hour of music at the same time and frequency as the RFA broadcasts into the Uyghur region.

Anyways, if you are interested in listening I am picking it up in San Francisco from about 0120 UTC to 0150 UTC on 7480 Khz.

I have also uploaded a snippet of the Chinese jamming of the Radio Free Asia broadcast from January 2, 2007.

Finally, here is a map showing the gray line through San Francisco at dusk (notice it goes right through Tajikistan. (click image for larger version). The map was created with DX Atlas.

While I am a little disappointed that it was not the RFA broadcast (which I could have received a QSL card for), it was actually a lot of fun trying to figure out where the signal originated from, and is one of the reasons I am getting hooked on DXing with my shortwave.

Btw, if you are interested, the RFA website has a cool do it yourself tutorial on how to make an anti-jamming antenna.