Korea Utara Memperbarui Pemancar dan Kemampuan Jamming

(sumber: Daily NK)

Otoritas Korea Utara sedang dalam proses mengganti pemancar radio gelombang pendek mereka. Langkah itu nampaknya ditujukan guna memungkinkan siaran-siaran yang lebih baik yang ditargetkan ke Korea Selatan dan menghentikan masuknya siaran gelombang pendek dari luar.

Menurut Northeast Asian Broadcasting Institute (NABI), pihak otoritas memulai tindakan tersebut pada Maret tahun ini, (mereka) menggantikan peralatan pemancar gelombang pendek di stasiun pemancar Kanggye di provinsi Jagang dengan peralatan modern buatan Beijing BBEF Electronics Group Co. Stasiun pemancar Kanggye adalah salah satu dari tiga fasilitas pemancar gelombang pendek di Korea Utara, sementara dua lainnya berada di Pyongyang dan di kabupaten Gujang provinsi Pyongan Utara.

Korea Utara memiliki dua broadcaster gelombang pendek: Chosun Central 1st Broadcast dan Pyongyang Broadcast. Broadcaster pertama diperuntukkan bagi audiens domestik dan internasional sedang kan broadcaster kedua hanya melayani audiens internasional.

Terdapat dugaan bahwa Korea Utara menggantikan pemancar yang telah ada guna memperbaiki siaran mereka yang ditargetkan ke Korea Selatan. Dengan peralatan modern dari BBEF siaran mereka akan bisa diterima di manapun di Korea Selatan, tak peduli dari manapun siaran tersebut disiarkan.

Menurut NABI, sebelumnya kapasitas siaran gelombang pendek Korea Utara  sangat lemah karena peralatan yang usang dan rusak. Kekuatan signal lemah, pendengar cenderung menerima channel yang berbeda bahkan ketika memantau secara langsung frekuensi yang dimaksudkan.

Menurut seorang pembelot Korea Utara yang tiba di Korea Selatan pada Juni 2012, kekuatan signal Chosun Central 1st Broadcast sangat lemah bahkan tidak bisa didengar di sebagian besar wilayah Korea Utara.

Akan tetapi baru-baru ini kualitas signal bertambah baik secara dramatis, sebagaimana dijelaskan Park Sung Moon dari NABI kepada Daily NK, “analisa yang dilakukan terhadap Cosun Central 1st broadcast dan Pyongyang Broadcast memperlihatkan siaran-siaran mereka disiarkan dengan jelas dan konsisten tanpa interferensi atau pergeseran signal.

Tujuan lain perbaikan pemancar gelombang pendek tersebut adalah untuk menghentikan signal lain mencapai pendengar. Menurut seorang pembelot yang pernah menjadi bagian dari Departemen Agitasi dan Partai Propaganda, “mereka tahu jika signal Cosun Central 1st Broadcast lemah dan biasanya terdengar bercampur dengan siaran lain. Saya rasa mereka ingin menghentikan hal ini terjadi lagi.”

(sumber:www.swling.com/blog) •hind

Pertanyaan Kuis Tahun Baru Radio Jepang NHK

1.       Orang Jepang di tahun baru meletakkan hiasan di depan pintu atau di pintu rumah, terbuat dari apakah hiasan tersebut?

a.       Momiji

b.       Sakura

c.       Matsu

2.       Setiap tahun baru televisi NHK mengadakan konser akbar yang disebut Kohaku Uta Gassen dimana kelompok putih dan merah bertanding dalam konser tersebut, bagaimanakah hasik Kohaku Uta Gassen ke 63 pada tahun 2012, kelompok mana yang menang?

Kirimkan jawaban ke:

NHK WORLD RADIO JAPAN

Indonesian Section, Tokyo, 150-8001,

Japan

RADIO JEPANG NHK WORLD

Kotak Pos 1245, Jakarta Pusat 10012

Indonesia

Situs web: http//www.nhk.or.jp/indonesian

Jawaban ditunggu sampai akhir Januari 2013

Daftar Monitor Resmi RTI-SI Tahun 2013

1.       Suriani

2.       Mariadi Purnomo

3.       Lim Kwet Hian

4.       Arsan H

5.       Eddy Setiawan

6.       Roni Yusianto

7.       M. Jayadi

8.       Rudi Hartono

9.       Saifun Najib

10.   Susi Cikampek

11.   Min Lin

12.   Hindun

13.   Fahri

14.   Sefrizal Arga

15.   M. Sumantri

SELAMAT Kepada 15 Monitor Resmi RTISI semoga semakin semangat dalam memantau radio yang menjadi kebiasaan langka di negeri ini, salam ( Hindun) 

The RF Grounding

First, we need to construct our RF (radio frequency) grounding. Without this grounding, the current can't flow through the primary winding of the transformer. Once the grounding is finished and we have made the transformer, we can do the first tests of our system.
The grounding is a 2,5 meter (8 feet) long copper water tube, at least 20 mm (0.8 inch) in diameter, found in your local DIY store (use blank copper tubes!). If you have the materials and the money, you may use a longer tube with a larger diameter. Select a location where rain can easily penetrate the ground. Try avoiding areas with concrete or large plants or trees, as those absorb a major part of the water and you'll be left with dry soil that doesn't conduct enough for our antenna system. You could make the surface descending a bit towards the grounding to guide rainwater towards it.
The tube is driven 2,5 meter deep in the soil. Don't try hitting the tube in the ground with a hammer (and bending it eventually). There's a far easier way to do this with the help of hydro-power! Simply take a piece of plastic tube with one end attached (witch a standard connector) to your garden hose, and the other end pushed over the copper tube and tightened with a clamping ring. Open the water tap and push the water spraying end of the copper tube in the ground. With the help of the water, the tube will go downwards with very little force. Oh, and wear boots or slippers, it gets pretty wet around you!
I managed to drive my copper tubes the full 2,5 meters into the ground within a mere 2 minutes! I encountered a clay layer but with some poking, it got through without any problem. You'll be amazed how fast this goes! Use grounding wire (flat woven copper car battery cable) or several twisted thick copper wires to connect the copper tubes to the antenna system. Connect the ground wire with a special electrical grounding clamp to the copper tube or twist it several turns around the tube and solder it with a big soldering iron or gas burner firmly to the tube. Seal off the connection with adhesive and/or heat-shrink to make the connection weather resistant.
IMPORTANT SECURITY NOTE: NEVER use the AC ground, found on the 220V outlets at home as RF grounding. Apart from being stupidly dangerous, the electric installation's grounding is the worst ever RF grounding. If you don't have a garden or suitable soil to drive the copper tubes into, you might consider burying copper wire radials horizontally in the top soil or laying them on the surface. These copper wires should run underneath the antenna wire and act as a virtual earth. Check the Internet for more info on RF radials.

The Transformer

The primary function of the 9:1 transformer (this type is also called Unun or unbalanced to unbalanced) is to bring down the very high impedance, typical for end-fed longwire antennas, to a lower impedance that is suitable for most receivers. An interesting property of this type of transformer is that the primary winding is directly connected to the ground, preventing the buildup of static on the antenna.
You could buy these Unun transformer but these quickly cost more than 30 Euros or $35 and most of them - sadly - don't have a separate ground connection. For receiving purposes only, you can make them yourself for less than 5 euro. The most expensive part will probably be its housing. I used a professional box, but you can just as well use a pillbox or a short piece of PVC water tube with two stops. Just make sure that the container is waterproof. There are plenty of DIY Unun construction ideas on the Internet.
Making you own transformer sounds scarier than it actually is. First, you need to find a suitable toroid ferrite core. For receiving purposes only, the core material, size and windings are far less critical. You can find such toroid cores (suitable to make HF transformers) in good electronic shops or on the Internet. If you really, really, can't get hold of a toroid ferrite core, you could recover the ferrite rod from an old portable radio. This will also work pretty well as transformer, but you'll have to experiment a bit with the windings. However, toroids are better transformers and they are immune to external electromagnetic interference because of their circular shape.
Here in Europe, Conrad sells the 26 mm toroid core part # 500671 for a few Euros. In contrast to the image on their website, they are well coated (in blue) and of good quality. I used exactly these and, as you can see in my SWL log below, they do an excellent job! You can use 0.5 or 1.0 mm enameled copper wire (the latter stays better in place but it gets a bit tight inside the core). Never use blank copper wire because without isolation you'll shortcircuit the windings! Before starting to wind, measure the circumference of one turn around the core and multiply that by 24. Add some 20 cm (8 inch) extra to connect the transformer.

We need 24 turns for the primary (large) winding, divided over three times 8 windings. Start winding the wire tight around the core and divide the 8 turns over the whole circumference of the core (see A). Bend the wire well around the corners to keep the wire against the core. Pass the starting point of the wire and continue to wind with the long piece of wire a second series of 8 turns, just next to the previous turns and finally wind a third series of 8 turns, again next to the previous windings (the result should look like B). The secondary (small) winding has only 8 turns. You start at the opposite side of the core and wind the 8 turns nicely next to the existing windings around the circumference of the whole core (see C) until you arrive back at the opposite side.
Note that some people wind such quadfilar toroids with four separate wires at once and then solder the separate parts of the wirings together. For such small toroids, I find it easier and faster to use a single wire for each winding. A good advice: start with a wire that is long enough!
Finished? Congratulations, you just made a quadfilar 9:1 transformer! Not that hard. Make sure to mark the primary and secondary windings so that you don't mix up the connections! Now that your first donut received its stripes, and before you put it in its housing, you might already want to do some quick testing. Solder one wire of the primary (larger) winding, one of the secondary (smaller) winding, and two test wires all together (scrape off the enamel before soldering). One of the test wires goes to the ground and one is soldered to the sleeve of a 3,5 mm stereo jack. The free wire of the primary winding goes to the antenna and the free wire of the secondary winding is soldered to the tip of a 3,5 mm stereo jack.
String up the long wire, put the jack into the receiver's external antenna socket and start testing all HF bands. Normally, 24 and 8 turns on the toroid should tune the whole band pretty well. If really necessary, adjust the number of turns (in that case, you'll need to rewind the toroid completely) with a few more windings to emphasize lower frequencies or a few less windings for higher frequencies. Do keep the same 3 to 1 radio (this provides the 9:1 transformation).
Finally, if you're happy with the result, unsolder the wires and put the toroid core in a watertight box. Solder the toroid wires to the connectors (solder grease makes the job easier): solder one side of the primary winding, one side of the secondary winding and the ground (chassis) of a BNC connector all together to the grounding bolt. The remaining wire of the primary winding goes to the antenna bolt, and the remaining wire of the secondary winding is soldered to the bus connection of the BNC connector.

Antenna Construction

The antenna is 21,5 meters (70.5 feet) of thin copper wire (a steel wire can also be used but copper has better electrical properties). This can be normal electrical copper wire (1 or 2 mm) or copperweld antenna wire (which is stronger than normal copper wire and doesn't stretch as much). You can use insulated wire, which also protects the wire against the sun and pollution. Its length is ideal for the 20 meters ham DX band (14.2 MHz) and a compromise that enables good reception on the lower and higher shortwave frequencies. If you use black insulated wire, you will have a very stealthy antenna. Such wires are virtually invisible. Antenna masts or trees that blend in the landscape are a plus (my wife loves gardens and dislikes antennas, but she never complained...so far).The antenna is attached to two insulators which are attached to nylon tension cords (3 to 4 mm). On one side of the antenna, the cord runs through a pulley downwards where a weight keeps the antenna wire straight (dangling copper wires eventually break). Select a weight that only prevents the wire from moving too much but doesn't stretches the wire until breaking point. On the other side, the cord is attached directly to the mast and the insulated antenna wire travels vertically down the mast to the 9:1 transformer. Never place the transformer at the top of the mast (like many do with a 9:1 balun for end-fed antennas), since you need a good - short - grounding. If you'd place it on top of the mast, the long grounding wire will capture additional interference since it acts as a second pole for the antenna. Also, don't try replacing the vertical part of the wire with a coax of which the shielding is grounded, in some kind of attempt to move the active part of the wire to the top of the mast. It "looks" like a good idea but unfortunately, the low impedance coax will act like a short-circuit to the very high impedance of the wire antenna and seriously attenuate the signal.

Insulator and antenna wire on top of the mast. The wire runs vertically down to the transformer.

Place one mast near the house and one mast as far away as possible from the house. The antenna should be place at least 5 meters above the ground (sloping the antenna wire only a few degrees - not to ground level - makes it more omnidirectial). You can use one or two masts or a big tree (big because those swing less in the wind) but never tie the wire directly between two fixed points without any system to relief tension (pulleys, spring...). When mast or tree are moved by the wind, or the wind catches the antenna wire, the copper wire will break rather soon than later.
You can buy insulators or homebuilt them yourself. The common white plastic 5 mm thick cutting boards, used in the kitchen, are great for this purpose. You can make insulators, like the one on the photo above, by sawing (or with a drill with circular cutting blade) two rounds, about 30 mm diameter, and two rounded rectangles. Next, you drill holes into the little rounds and the rectangles, place the rounds between the rectangles and fix them together with two bolts. I also drilled two little holes at the side of the insulator to attach straps that support the wire that goes down.

Building a good Antenna System

SECURITY AND LEGAL WARNINGS Outside antenna systems are considered electrical installations that must comply with safety regulations that may vary depending on the area where you live. Enquire at your local government, fire department and home insurance broker about the regulations regarding construction of outside antennas, proper grounding and connection of radio equipment to the mains. You could be held responsible, legally and financially, for any damage that is caused by your installation (lightning strike, fire, injuries) when you fail to comply with local regulations. The antenna systems, presented on this page are for receiving purposes only with a portable receiver that is either battery operated or connected to the electrical mains by an adaptor with galvanic isolated transformer without ground plug (not the electronic adaptor type).

Good reception is only possible when you have both a good radio and a good antenna system. Even the best receiver is useless without a good antenna system. We should point out the essential difference between "antenna" and "antenna system": an antenna captures radio waves and an antenna system is the comprehensive installation that brings the radio waves in good condition to your radio.
Now, there's often some misunderstanding about antennas. If you have an antenna that has the correct length, you can never make it receive more or better. What you can do is to place it in the ideal position to capture signals, and you can reduce the noise level so that the signal is more readable. The signal-to-noise ratio is what makes the signal readable. Even very weak signals are more readable than strong signals if they carry less noise: you simply turn up the volume. If you experience too much noise, turning up the volume will turn up the noise equally, even on strong signals. The good news is that anyone with basic soldering experience can homebuilt a good antenna system that provides excellent reception for less than 100 Euros or $120. You don't need to be familiar with electronics or radio technology.
IMPORTANT! The antenna systems, describes on this page, are only suitable for receiving purposes and should never be used to transmit. The toroids are not suitable to dissipate the power and the impedance of the system is not adapted to the transceiver output.
Below the circuit diagram of a commonly used long-wire antenna system: the wire antenna is connected to a 9:1 transformer, also called UNUN (Unbalanced to Unbalanced) that is grounded to a 2,5 meter (8 feet) long copper tube, driven in the ground. The 9:1 transformer brings down the very high impedance of the end-fed wire antenna to an impedance that is suitable for both coax and receiver. The feedline transports the signal to a wall connection box. From there, a coax brings the signal to the external antenna jack. The transformer ground, and optionally receiver ground, are connected to the grounding rod with the shortest possible wires, all near the entry of the coax into the house.

Inside the house, the coax that comes from the transformer is connected to the connection box with a BNC chassis connector which in turn is connected to a second BNC chassis connector at the front of the box. The easiest way to connect the external antenna jack to the inside coax cable is to use a small box with on one side a BNC chassis connector that is soldered to the wires that go to the antenna jack. Make sure that the coax ground (shielding) is connected to the sleeve of the jack and the core wire of the coax is connected to the tip of the jack.
WARNING: this is how the external antenna connection works on my Sangean ATS 909X and on some other brands. However, other radios might have another antenna socket wiring setup! Inform yourself about how to connect the external antenna to your radio! I'm not liable for any damage, caused by an incorrectly connected antenna.
Never accidentally insert the external antenna jack into some other (audio) jack. They look the same and are mechanically the same, but I don't know what it could do to your radio, since the transformer output virtually short-circuits LF and DC signals. I accidentally inserted the antenna jack into the headphone socket of my 909X a few times (stupid me) without any damage. Nevertheless, be careful not to do so. You might attach a flashy warning label to the cable, next to the jack, as our brain is conditioned to put such jacks always into an audio socket.
If your receiver has a separate grounding connection (often with butterfly nut), you can connect that ground to the ground connection of the wall connection box. It is strongly advised to use one single grounding point and to connect each of the separate parts of the antenna system, each with its own heavy gauge or flat cable grounding wire, to that single grounding point, and to keep these wires as short as possible.

BERITA DARI JERMAN

20 Tahun SMS - Ketika Pesan Teks Dikirim Melalui Ponsel

Satu inovasi besar di awal tahun 1990an: pesan singkat lewat ponsel. Saat ini, di seluruh dunia, jutaan SMS dikirim setiap harinya. Namun keberadaan SMS terancam teknologi baru.

“Datang terlambat. Harus selesaikan sesuatu” – teks pendek yang menjadi ciri khas SMS. Dan kalimat ini biasanya juga masih diperpendek dengan menyingkat setiap kata. Selama 20 tahun terakhir, penulisan SMS berkembang menjadi satu kultus penulisan singkatan. Terdapat banyak situs internet yang khusus menyediakan daftar ratusan singkatan kata penulisan SMS.
Pesan harus ditulis sependek dan sesingkat mungkin: itulah SMS. Jumlah standar penulisan adalah 160 karakter. Sepertinya ini hanya kebetulan saja, namun sebenarnya pembatasan ini memang direncanakan oleh para penemu SMS. Sejak pertengahan tahun 1980an telah dikembangkan konsep SMS, yang menjadi model adalah kartu pos dan pesan teleks. Dan ketika diteliti, ternyata hampir semua pesan yang dikirim lewat kedua media ini tidak lebih dari 160 karakter – sehingga diputuskan untuk membatasi jumlah karakter dalam penulisan SMS.

Pada tahun 2011 46 miliar SMS terkirim di seluruh dunia

“Selamat Natal” – Ibu Pesan Pendek
Saat SMS pertama dikirim pada tanggal 3 Desember 1992 tidak banyak yang mengetahuinya. Ini tidak mengherankan karena teknologi transmisi pesan teks ini belum berkembang. Dan ponsel pertama, yang ada saat itu seharga 1.500 Euro, tidak bisa mengirim dan menerima SMS. Oleh karenanya SMS pertama ini tidak dikirim melalu ponsel, melainkan komputer. “Merry Christmas“ demikian pesan yang ditulis para teknisi Vodafone Inggris, yang pertama berkesempatan menguji layanan SMS.
Raup Keuntungan lewat SMS
Bahwa SMS dapat menjadi tambang emas bagi para penyedia layanan ponsel tidak diramalkan pada awalnya. Baru kemudian, secara bertahap, perusahaan penyedia layanan ponsel mendapat ide untuk mengenakan biaya pengiriman SMS, dikatakan Rafaela Möhl, juru bicara teltarif, satu layanan online di Jerman.

Rafaela Möhl

Sejalan dengan booming industri ponsel sejak pertengahan tahun 1990an, terjadi perubahan besar dalam perkembangan SMS. Jumlah pesan pendek yang dikirim meningkat dengan drastis: Di Jerman saja, pada tahun 1996 dikirim sekitar 100 juta SMS. Bundesnetzagentur, badan yang mengurusi pasar listrik, gas, telekomunikasi, pos dan kereta api, memperkirakan, pada tahun 2011 terkirim 46 miliar SMS. Satu bisnis raksasa: dengan biaya sekitar 1.200 Rupiah per SMS, keuntungan besar diraup para operator ponsel.
Saingan dari Internet
Masa keemasan SMS lambat-laun berakhir. Dengan semakin menjamurnya smartphone atau ponsel pintar, tumbuh pula cara-cara baru untuk mengirim pesan. Para penyedia jasa layanan ponsel sudah menyadarinya, dikatakan Urs Mannsmann, editor majalah komputer c't. “SMS telah mencapai puncaknya. Sekarang akan digantikan oleh layanan internet.”

WhatsApp menggeser SMS

Dan para operator jaringan internet menanggapi perkembangan ini dengan menyediakan tarif tetap internet, termasuk untuk jasa pengiriman SMS. “Ini menyebabkan, jumlah pengiriman SMS stagnan, namun para operator internet telah meraih keuntungan.“ Operator interne5 yang dimaksud Mannsmann adalah terutama aplikasi messenger bagi smartphone, WhatsApp.
Dengan aplikasi ini, para pengguna dapat mengirim pesan melalui internet tanpa dikenakan biaya. Kelebihan yang dimiliki Whatsapp adalah, jumlah teks tidak dibatasi serta dapat mengirim foto dan video. Namun kekurangannya adalah, baik pengirim maupun penerima harus terlebih dahulu mengunduh aplikasi ini. Dan ponsel konvensional, yang tidak dapat mengirim data melalui internet, tidak dapat memanfaatkan aplikasi Whatsapp. Aplikasi ini kini tengah berjaya: setiap harinya, lebih dari 10 miliar pesan dikirim melalui Whatsapp.

Urs Mannsmann

Joyn – Upaya Operator Ponsel untuk Bersaing
Aplikasi Whatsapp tidak hanya mengancam model bisnis SMS yang dimiliki operator selular. Dalam “satu gebrakan“ aplikasi ini juga turut menyingkirkan “saudara tiri“ SMS, yaitu layanan pesan multimedia MMS. Agar tidak sepenungnya tersingkirkan oleh aplikasi seperti Whatsapp, para operator ponsel kini memperkenalkan satu program messenger baru bernama Joyn. Program ini antara lain dapat mengirim pesan pendek, file, suara dan percakapan video. Biaya yang dikenakan untuk layanan ini sama seperti biaya SMS, MMS dan percakapan telefon, tergantung pada tarif penyedia layanan ponsel.
Namun Rafaela Möhl dari teltarif meragukan bahwa operator ponsel akan mampu bersaing. ”Saat ini bisa saya katakan, sangat sulit bagi operator ponsel. Whatsapp telah jauh di depan. Joyn harus menawarkan kelebihan yang besar. Tapi saat ini, saya tidak melihatnya.“