mike.chambers

URL Encoding with Objective-C and Cocoa

I have been teaching myself Objective-C and Cocoa (in part so I can build native iPhone / iTouch apps), and have been working on a simple command line application named "turl". This basically provides a command-line interface to url shortening services such as tinyurl.com and urltea.com.

Anyways, I ran into an issue where a specific URL was not being created correctly. It turns out, it was because I was not url encoding the url before sending it to the api. No problem I thought, I'll just url encode it. However, after much searching, I found that Cocoa didn't really provide a url encode API. I did find find a couple of possible solutions that used other APIs, but I could not get either one to work for me, and it didn't appear that they were made specifically to URL encode urls.

So, I finally decided to make my own and figured I would post it here in case anyone else needs to use such an API.

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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):

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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.

Continue reading "Clip of Cuban Jamming of Radio Marti"

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.

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Images of new International Airmail Reply Coupons

I picked up some International Airmail Reply coupons the other day to include with QSL requests. Since these are the new versions, I figured I would post the images here in case anyone was interested.

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VoiceOfKorea.org down? COUP D'ETAT? (Updated)

I checked out voiceofkorea.org tonight (the website for the Voice of Korea shortwave broadcast from North Korea), and found the following on their website:

COUP D'ETAT

CONSCIENCE AGAINST REASONS OF STATE

VOICE OF KOREA IS TEMPORALLY NOT IN OPERATION

Further information will be given on Tuesday 02/01/07

info@voiceofkorea.org
0044.(0)79.0880.8552
Jean-Baptiste Kim

I archived the page in HTML and PNG.

Anyone know what is going on?

Updated January 1, 2007 : The website has been updated with a repudiation of the North Korean regime:

The current regime is not the leader of people but the royal family rules over the people. This should changed into democratic elections and extended freedom of speech. People's lives must be chosen by people's favours, not by the dictatorial system. ... I regret my life with DPRK government for last 10 years but will not repeat the same mistake again in future.

voiceofkorea.org was a volunteer ran website for the North Korean government (with North Korean approval).

I have archived the page here.

New Antenna : Good Night of DXing

Well, I finally got around to putting up a new antenna. I had been using about a 40 foot wire that ran out my window and up the hill along the group. I had been picking up a lot of interference, and not really able to pull in that many stations.

Well, today, I ran about 60 feet of wire, but elevated it from a pole on the hill to the side of my house. Pretty simple, but the difference in reception tonight has been amazing. I have been getting tons of stations, but the best two of the night were:

Continue reading "New Antenna : Good Night of DXing"

My First Numbers Station

Shortwave reception has been very poor lately, mostly due to a broken streetlight that is causing massive interference with my receiver, so I have really only been able to listen to major stations, and haven't been able to try to find any far off stations or other stuff. However, last night when I was doing a scan of the frequencies, I came across a very strong numbers station broadcast. This is my first numbers station since I have gotten back into Shortwave.

Here are the details:

December 30, 2006 - 0941 UTC - 0945z 9040z Khz. Female repeating a set of numbers in Spanish. SIO : 434

Luckily, I had just set up an old mac to record audio from my shortwave, so I was able to record everything I heard.

Listen to Numbers station, Female in Spanish

I haven't had a chance to write down the number sequence just yet, but will try to a little later and update the post. If anyone does it before then, or has any more infor on the broadcast, please post in the comments.

No Success at First try at Voice of Korea

Well, after receiving my new receiver Eton E5, I finally decided that this morning would be my first attempt to pick up the Voice of Korea (a broadcast from North Korea). Unfortunately, that meant getting up at 5 AM (1300 UTC), but I didn't mind too much, as I really want to hear some heavy duty, old school communist propaganda.

Anyways, the only signal I could pick up here in San Francisco was at 9335. I was able to pick it up (faint and muffled), but it was completely unlistenable due to some interfence from something (another frequency? eletrical?). Basically, it was a periodic tone of increasing static, that would repeat ever couple of seconds. Here is a clip of it:

Listen to clip of Voice of Korea broadcast with interference

When I tuned around on my receiver, it seems to be the strongest on 9339. I am not sure if this is some interference from my house (I am in a very electrically noisy area), or if this is something being broadcast.

Tonight / tomorrow morning I am going to head up to the top of the hill to a park, and see if I have any more luck.

Anyways, here is the report:

Voice of Korea North Korea. (English) 9335 1300 - 1349 UTC. SIO 211. Assorted Male and Female speakers. Some references to the Great Leader, and patriotic / communist music.

If any one has any idea what the source of the interference is, post it in the comments.

Update : Well, based on a tip from rec.radio.shortwave, I found the source of the interference. The street light on the corner is burned out, and everytime it tries to come on, it generates the interference. Now, instead of DXing, I get to figure out how to get a street light fixed in San Francisco.