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Sunday, October 30, 2011

Words From Fabian DJ1YFK About Morse

Like you, I have heard and read about this often (copying whole
words rather than single letters), and I think it is a little bit
misleading. I can easily copy plain text CW in German or English
at around 80 WpM, but still, if I actively, consciously listen, I
*do* hear every single letter. 

But that does not mean that I have to concatenate those letters
to form a word, like a first grade pupil does, when he reads an
unknown word (I also recently encountered this problem again
while learning Macedonian, written in cyrillic letters!). I
rather make an assumption on what the word could be, often even
before the word is transmitted. By making such predictions (and
in most sentences you can easily predict the following word; or
if not, you can predict the word based on the first letter, or
make some rough assumptions of what might come next), you can
stop to worry about the word after you have recognized the start.

If, however, an unexpected word appears, you have to change the
plan in your mind, and decode it consciously. In most cases
again, the first two or three letters will be sufficient to make
a safe assumption on what the word will be. In cases of unknown
names (operator, QTH, ...) you might have to go back to putting
it together letter by letter.

I think everyone copies plain text CW similar to this, to a
certain degree. It starts with your first standard QSOs: Those
ever repeating phrases ('tnx fr rprt = ur rst 599 ='...) are soon
'hard coded' into your brain. They are so easy to copy because
it's what you *expect* to hear. If the other station suddenly
starts sending something _unexpected_, you're getting into
trouble or at least you'll suddenly have to pay close attention.
The reception is moving somewhere from your subconsciousness to a
higher level of consciousness. 

After my first 50 CW QSOs, I stopped to write down every single
letter, and only had to write everything that was not the
expected stuff like "my name is", but the names/QTHs itself. 

So, hearing a whole word as one 'sound' does - in my personal
experience - not work, you still hear it letter by letter. But
the more routined you are, the deeper the process of perception
slides into your subconsciousness.

Fabian Kurz, DJ1YFK * Dresden, Germany * http://fkurz.net/


Quite often I am asked "How can you copy CW at 70 wpm and higher?" Since it's pretty insulting just to answer by  saying "Practice, practice, practice", I normally wind up emailing back a synopsis on how I learned to do it. Others have used different methods of achieving QRQ copy by ear.
What I have to say on this subject is only my own personal opinion, which normally does not agree with everyone else!

I really don't believe in the various methods of learning code. I think learning to copy high speed code is much simpler than following someone else's method of learning to copy QRQ. What I am sharing with you is things that I found to work for me.

There are some basic's I think one MUST learn, and the very first one is you must learn to copy ONLY in your head. That's very important! From there you can begin to increase your copy speed. So copying in your head is a MUST. Jotting down notes or 'key words' is fine to remind you of something you want to respond to during your QSO.

QSO'ing at 70 to 120 wpm is literally no different than having a conversation on the telephone; you are  just doing it using a different language! No sending call signs (except as required) and no sending 'bk'. You don't do that on the telephone! Speaking on a telephone is operating duplex, therefore why not do the same thing on CW?

A second most important thing you must do is have a radio that has excellent full QSK at high speeds.  Simply because when operating QRQ, you MUST do it in duplex! You don't stop and take notes when your conversing on the telephone, so why do it when your operating QRQ? The radios that I know of that can run full QSK at speeds over 100 wpm are the Ten Tec Corsair II and the Icom IC-781, and they do it flawless. In my opinion, full QSK is not at what speed you can hear another signal between dots, but at what speed can you hear your fellow ham trying to break you! Hearing between dots is a fine criterion for speeds below about 40 wpm, but is inconsequential over 60 wpm. Unfortunately the more digital circuitry that is added to modern transceivers, the less high speed QRQ capable they become.

All high speed code (above about 55 wpm) is sent with a keyboard/keyer or a computer keyboard, simply because one just cannot consistantly send 'clean' code by hand on a key. Consistently 'clean' code makes for easier copying! I've been a CW operator for over 55 years but I am not one of those 'old goats' who claim that sending CW by any other means than using your had is not 'real' CW. 'Real' CW is a dot and  a dash, no matter how you send it. The idea here is how you copy QRQ, not how you send it!

Most computer programs that are capable of generating CW are, for some reason, not designed to exceed about 99 wpm. And most computer programs generate CW either via a serial port or a parallel port. Using these I/O ports causes an inherent problem for smooth CW generation. A computers CPU produces random (to us) interrupts which almost always stops activity in any I/O port FIRST! This leads to a 'stutter' sound in generated CW coming from these I/O ports. VE6YP, who is the author of the program I've been using for close to 10 years, is the only program author I know of who has found a solution to this problem. In his program, YPlog, he generates CW via the computer sound card, which is never interrupted by a computers CPU 'house-keeping'. The user builds a very simple audio detector and transistor switch to key his radio. This system works very good to over 160 wpm.

The reason you first want to learn to copy in your head only is because when you get to speeds around 50 to 55 wpm, you have to teach your brain literally to change it's method of interpreting code.(And it takes a while to do this!) Below about 50 wpm, you are still hearing a dot and a dash to form a word. When you are copying at 60 wpm and higher, you do not consciously hear a dot and a dash, you literally hear a word. At that time too, you begin to have to be in, what I call, the 'flow of the conversation', just like you are when your talking on your telephone. If you send me code groups at 70 wpm, I could not copy most of them, but if you and I are in a converation at 70 wpm or higher, THEN I can copy pretty solid.

To increase your copy speed, I recommend a code reader...and don't be shocked by that! The reason I recommend a code reader is because the process of learning to copy from about 50 to 60 wpm is where you literally have to teach your brain to copy code in a different way. The problem at these speeds is if you miss a word, your brain automatically freezes and tries to 'guess' at what that one missed word is. While the brain is trying to decide what that one word is, many more words go flying by, and you actually get very confused and lose track of what is being sent to you. When you start using a code reader, a first you're going to just read the screen, but subconsciously the brain is associating the dots and dashes with what your reading on the screen. The more you do this, you will find that the less you read the screen, but only glance at it when you miss that one word! This gets you over that 'brain freeze' that is caused by missig just one word! Once you get to copying around 60 wpm, when you DO miss that one word, your brain realizes it, but then just continues to copy, ignoring or filling in that one missed word.

Don't worry about a code reader being a crutch, simply because when you get to where you can copy around 60 wpm, you will find that you can then copy code better than a code reader! A code reader is not very good at handling high speed code in the presence of normal band noise of your receiver. About 60 to 70 wpm and they are not capable to keep up anymore because of noise crashes, but your brain can easily filter out the noise. A code reader is an 'aid' to helping one learn to copy code faster, it is NOT a crutch!

[[just for info: Although you will not be conscience of copying dots ad dashes, if the sender mis-spells a word, somehow your brain will notice that. Say the sender sends the word 'will' as w'E'll, your mind will notice that one dit that was missed, but you will have trained your brain to ignore that one missed dit, and it will continue copying. I'm not truely sure of this but I think somewhere above about 70 or 80 wpm, since your mind is now really in the 'flow of the conversation', you probably are not literally copying every word that is sent to you, but your brain is copying enough to make sense out of what is being said!]]

Two big things about QRQ:
1) You HAVE to make it just another FUN thing you want to do with your hobby.

2) You are not going to learn to do it over night! But anybody can learn to do it.

I got started doing QRQ sometime in the late 60's when I heard two hams talking to each other on their regular skeds on 40m, at 100 wpm. I thought it was just very fascinating, and just decided that was something I WANTED to do. And it took me about a year to go from 30 wpm on my keyer to over 60 wpm. That includes the time it took me to change from a QWERTY keyboard to a Dvorak style keyboard. The neat and fun thing I found, is that once you get to where you can copy between 60 and 70 wpm, your mind seems to just open up to copying QRQ. Going from 60 wpm to say, 100 wpm, seemed to be a breeze compared to retraining my brain to get through the 50 to 60 wpm 'brick wall' we all have to go through.
I really don't know how fast I could copy, but I used to have QSO's with KB9XE and NU2C at about 120 wpm and could fully understand what they were saying. NU2C tested me once and he would send me two questions, which I had to answer both, then he would go up about 5 wpm . Finally at 145 wpm, I got only one of his questions! I have read that recently a German ham did copy a call sign being sent my RUFZ (a high speed competition program) at 200 wpm! Copying CW at high speeds, either 145 wpm or 200 wpm, is one thing, having a conversation at those speeds is something quite different.

Again, two things. You have to make this a fun-thing, you have to want to do it, and it can get pretty frustrating at times. You have to be willing to spend the necessary time on the air working at improving your copy. That is the only way I know of that you can do it, as there are no short cuts. Interestingly, of the maybe 10 hams that I know that operate at high speeds, none of the have any interest in records or reconition for their QRQ ability. They all simply do it for the enjoyment of it.

from http://sites.google.com/site/tomw4bqf/copyingcwover70wpm

This Is Ham Radio - A Vintage Film

Moving Up to Amateur Radio - A Vintage Film

Wednesday, October 26, 2011


Phonetic alphabet adalah satu bentuk sebutan bagi mewakili sesuatu huruf atau nombor. phonetic alphabet sudah lama digunakan dalam bidang komunikasi suara bagi memudahkan penghantaran dan juga penerimaan sesuatu mesej.

dalam radio amatur di Malaysia, terdapat beberapa station yang agak fanatik tentang penggunaan phonetic alphabet ini. setiap perkara yang ingin disampaikan semuanya dalam bentuk phonetic. kadangkala akan menimbulkan sehingga menimbulkan kekeliruan dan komunikasi menjadi tidak relevan.

jika disebut KILO LIMA, bunyi tersebut mewakili huruf K dan L. adakah ini mewakili KUALA LUMPUR ?
boleh jadi KUALA LIPIS, KOK LANAS dan sebagainya. seharusnya perbualan mesti lah straight forward. tidak perlu menyukarkan perkara yang mudah dan jangan pula memudahkan perkara yang sukar.

jika perbualan di HF yang adakalanya bising, sebutan ALFA kadangkala didengar sebagai PAPA. bagi mereka yang sudah biasa, ALFA boleh digantikan dengan AMERIKA. bagi penduduk negara Jepun, Taiwan, Korea ataupun China, mereka kadangkala tidak boleh menyebut ALFA. orang Jepun menyebut OVER sebagai OBAR. kita tidak boleh salahkan mereka, sepatutnya jika harus berfikir dengan bijak dan kembali kepada objektif iaitu contact. satu contact boleh dikatakan tidak berjaya jika callsign kita tidak difahami oleh station yang menjawab.

mari kita lihat sejarah phonetic alphabet sebelum tahun 1956,

1914–1918 (WWI) 1924–1942 1943–1956 1941–1956

tidak menjadi mandatori dalam sebutan phonetic radio amatur, jika kita bertengkar tentang phonetic maka objektif utama dalam contact radio amatur tidak akan berjaya. cuba dengar perbualan di HF kalau tidak percaya. A tidak semestinya ALFA, boleh jadi AMERIKA. bergantung kepada situasi. seperti yang sudah dijelaskan di atas, adakalanya ALFA di dengar sebagai PAPA.

perbualan dalam mode FM di VHF adalah jauh lebih bersih dan jelas jika dibandingkan dengan HF. jika report yang diberi adalah readability 5 dan signal strength 9, sudah tentu huruf A akan di dengar sebagai A. jika anda menyebut 9M2PJU dan bukan niner mike two papa juliet uniform, adakah station lain tidak faham ? kadangkala phonetic melambatkan komunikasi, apa guna phonetic alfabet jika disebut dengan laju ? apa guna disebut 9M2PJU dengan laju ? sudah tentu akan mengelirukan. dan cuba fikirkan, jika huruf disebut huruf dan disebut dengan perlahan-lahan dengan nada yang jelas, pasti mudah difahami orang lain. pendek ringkas, jelas dan senang difahami. kita seharusnya berfikiran secara terbuka dan mampu adapt kepada situasi dan bukanlah berkeras mengikut rasa hati.

IKVT adalah singkatan kepada IRAMA, KEKUATAN, VOLUME dan TONE. irama yang mudah difahami, kekuatan yang sesuai, volume yang lantang dengan tone yang jelas memudahkan komunikasi.
seharusnya mesej yang hendak disampaikan perlu dititikberatkan dari phonetic yang disebut. cuba fikirkan, apa kata station dari negara lain jika anda memarahi station Jepun kerana menyebut ONTARIO dan bukan OSCAR ?


CW DXing adalah satu aktiviti radio amatur yang mana seorang operator radio amatur membuat contact dengan station yang jauh cuma dengan menggunakan peralatan seperti Morse key, transceiver, transmission cable dan antenna. peralatan lain seperti linear amplifier juga boleh digunakan untuk menambahbaik prestasi pemancaran, band pass filter juga bagus untuk digunapakai. jika anda mempunyai radio yang ada fungsi seperti filteration, noise reduction sudah tentu operasi anda menjadi lebih senang. bunyi bising noise boleh disekat, dan juga anda boleh mengecilkan range penerimaan isyarat.

selalunya operator akan memulakan CW DXing dengan menanya samada frekuensi yang dipilih sedang digunakan atau tidak. QRL ? QRL ? QRL ? dihantar dan jika tiada station yang menjawab, maka frekuensi itu dapat diandaikan sebagai frekuensi yang tidak digunakan. jika ada station yang menjawab Y, QRL ataupun R. maka frekuensi tersebut sedang digunakan. jawapan tidak semestinya Y, QRL ataupun R. adakalanya station lain menjawab dengan jawapan yang lain.

apabila frekuensi yang dipilih tidak digunakan, CQ CQ CQ DE 9M2PJU dihantar beberapa kali untuk memanggil mana-mana station yang mendengar di frekuensi itu. selalunya station lain akan menjawab dengan callsignnya, ataupun DE 9M2AR ataupun BK 9M2AR. perkara yang penting dalam contact adalah signal report. dalam CW, selalunya signal report di beri dalam RST iaitu readability, signal dan juga tone. 599 adalah signal report kepada isyarat CW yang sangat jelas diterima beserta pitching yang bagus.

berikut adalah contoh contact dalam CW,






ini adalah contoh CW QSO, seharusnya setiap transmission di akhiri dengan callsign. bagi mengelakkan kekeliruan. SK bermaksud end of contact dan E E bermaksud bye bye.

terdapat banyak abbreviation dalam CW, ada sesetengah operator menghantar TKS sebagai THANKS. ada juga operator yang menghantar TU bagi thank you dan ada juga yang menghantar TNX sebagai thanks.

GE, GM, GA, GN adalah singkatan kepada good evening, good morning, good afternoon dan good night.

GL adalah singkatan bagi good luck.

terdapat banyak singkatan dalam CW, terdapat banyak rujukan di internet. taip sahaja CW abbreviation anda akan mendapat banyak jawapan. sangat susah untuk bermula dengan CW, tetapi jika anda sudah bermula, anda akan dapati CW QSO sangat menyeronokkan, dengan kuasa yang rendah, setup yang sederhana, isyarat anda dapat didengari oleh station dari negara yang jauh.

jika anda tidak mempunyai kebenaran untuk bekerja dalam mode CW, anda boleh berlatih dalam satu kumpulan, dengan menggunakan CW trainer keyer, cuba hantar CW kepada rakan anda dan rakan anda akan membalasnya. sudah tentu tiada kesalahan kerana anda menggunakan frekuensi radio. tiada alasan untuk mencuba dan belajar. jangan jadikan perkara remeh-temeh sebagai halangan untuk anda belajar.

jika anda tiada callsign yang membenarkan anda bekerja dalam mod CW, anda boleh menggunakan callsign kelab. ditemani oleh station master yang berpengalaman dalam CW, sudah tentu anda dapat belajar banyak perkara. SSB operation mungkin jauh lebih senang, tetapi jika anda ingin mencuba CW operation, tiada salahnya. apa pun tepuk dada tanya selera. bayangkan dengan hanya 0.5watts, isyarat anda dapat sampai ke Jepun. cuba dengan SSB operation, berapa jauh anda boleh sampai ? mungkin lebih, mungkin lansung tidak sampai. apapun jangan mengalah. hobi sepatutnya tidak boleh dipaksa, ukur baju dibadan sendiri, jika tidak mahu, boleh cuba mod lain. setiap mod mempunya pros dan cons sendiri. bergantung kepada peralatan anda juga. apa guna SSB operation jika tidak mampu berkomunikasi dalam bahasa inggeris ?.

Monday, October 24, 2011

QSL Card Dari Belgium

QSL kad dihantar sebagai 'confirmation' di antara 2 station radio amatur hasil dari 'contact' yang telah dilakukan ataupun sebagai short wave listening report. ada beberapa radio amatur dari negara asing memerlukan beberapa jumlah QSL kad dari station lain untuk menaiktaraf kelas lesen dan ada juga untuk menukar callsign kepada callsign yang pendek seperti vanity callsign. sesetengah radio amatur mengatakan bahawa QSL kad mempunyai 'sentimental value'nya sendiri.

ini adalah QSL kad yang diterima dari Belgium hasil dari 'contact' dalam mode CW atau kod morse di 7MHz.

Friday, October 21, 2011

Basikal Dan Radio Amatur

Ya, basikal dan radio amatur. apa kaitannya ?

mari kita lihat dari beberapa sudut, basikal adalah satu bentuk pengangkutan pada asalnya dan telah berevolusi dari zaman ke zaman. pada masa sekarang basikal sebagai pengangkutan tidak berapa diterima oleh sesetengah invidividu tetapi, bagi mereka yang suka beriadah ataupun sukakan aktiviti luar rumah (outdoor), basikal adalah antara yang terbaik.

terdapat beberapa jenis basikal dipasaran, basikal untuk kanak-kanak, untuk pemula (beginner), basikal off-road, basikal on-track dan juga basikal untuk atlit profesional. boleh dibeli dalam harga yang murah juga harga yang agak mahal, mengikut kemampuan masing-masing. aktiviti berbasikal sudah mula diterima masyarakat, sebagai salah satu medium untuk bersenam disamping itu dapat juga melegakan dari tekanan selepas waktu kerja.

bagi operator radio amatur, sambil berbasikal juga mereka boleh menghubungi radio amatur yang lain pada sesuatu waktu. peralatan seperti radio VHF, UHF dan juga HF boleh dipasang pada basikal jika tahu caranya. faktor yang perlu diambil berat adalah seperti grouding system, antenna system memainkan peranan yang penting. disamping itu juga faktor keadaan sekeliling perlu dilihat.

anda boleh menikmati 2 hobi sekaligus jika fikiran anda positif. pilihan adalah ditangan kita. pada waktu emosi yang berkecamuk, tiada idea dan juga ketandusan pendapat maka lebih baik anda mendengar dari mencelah. bagi mereka yang mempunyai radio all band all mode, anda boleh memasang radio ini pada basikal anda. sambil mendengar kepada perbualan radio amatur lain, anda juga boleh tala ke frekuensi radio komersil. berita seperti kejadian terkini, ramalan cuaca sangat penting untuk anda mengatur perjalanan anda dengan basikal.

phone operation sangat sesuai untuk radio amatur yang berbasikal. anda boleh menghubungi radio amatur lain untuk memaklumkan akan perjalanan anda, disamping itu guna sangat berguna apabila terjadi kejadian yang tidak diingini. bagi mereka yang sukakan CW mode, iambic keyer boleh di pasang pada handle basikal bagi memudahkan anda untuk memetik key tersebut. dengan bekalan kuasa yang terhad seperti bateri ataupun solar panel dan kuasa pancaran yang sedikit, anda boleh bekerja dengan station yang jauh mengikut keadaan band yang anda gunakan.

semua hobi dapat memberi kita ilmu jika kita pandai melihat dari sudut yang positif. jika pikiran kita penuh dengan tanda tanya, kita seharusnya merujuk kepada mereka yang pakar dalam bidang tersebut ataupun mereka yang komited akan bidang tersebut. orang yang lama ramai yang pakar, tetapi tidak semestinya pakar, mereka perlu dihormat kerana pengalaman mereka. mungkin banyak, mungkin sikit, sangat subjektif. dan tidak boleh dijangka. old generation learn first, new generation comes next. janganlah pula membuat andaian dan juga amalan sendiri. masyarakat dunia memandang tinggi kepada mereka yang beretika. etika adalah sangat penting, etika juga lah yang membezakan radio amatur dan juga penunggang basikal samada berhemah ataupun tidak.

jika anda seorang operator radio amatur, anda seharusnya tahu apa yang sepatutnya dibuat dan apa sepatutnya yang harus dielakkan. sama juga dengan penunggang basikal, anda perlu tahu apa itu undang-undang jalanraya. kita hidup di dalam satu aliran yang sama, manusia yang hidup akan mati, dari atas akan turun ke bawah. berpesan dan menegur sesama sendiri adalah perkara yang baik, tetapi kehormatan individu juga harus dijaga.

basikal dan radio amatur adalah perkara yang berbeza tetapi tidak mustahil jika digabungkan, berbasikal sambil berhubung dengan radio amatur yang lain tidak rugi jika dipraktikkan. ke semua perkara ini adalah bergantung kepada individu, tepuk dada tanya selera. jika mampu teruskan, jika rasa tertekan lebih baik dielakkan. perubahan ataupun peningkatan diri bergantung kepada diri masing-masing, tiada orang yang boleh mengubah kita, jika kita sendiri tidak mahu berubah.

mari kita lihat video-video  aktiviti berbasikal sambil berhubung melalui radio,

Sunday, October 16, 2011

Break Atau Mayday ?

  Oleh kerana ramai radio amatur di Malaysia mengatakan bahawa "break" adalah untuk distress call. Mari kita bercerita tentang penggunaan break dan mayday di dalam prosidur suara radio amatur.

Tahukah anda,

menurut "THE EMERGENCY COORDINATORS MANUAL" yang telah diedit oleh Steven WV1X dan telah dipublish oleh American Radio Relay League (ARRL) mengatakan bahawa,

16) The word “break” is never used UNLESS there is an emergency. Otherwise, use your call letters to gain access to the net.

Note: The practice of using “BREAK” or “BREAK BREAK” to announce distress traffic should be strongly discouraged; it has no universally understood meaning. Always use the international standard “MAYDAY” or universally understood “EMERGENCY” to announce traffic of life-ordeath importance. The standard CW signal is “SOS,” sent as a single character—not spaced as three letters.

baca dan fahami perenggan ini, adalah break itu orang yang dalam kecemasan melibatkan nyawa ataupun orang yang mem-break-kan perbualan untuk mencelah masuk ? atau lain-lain.

jika anda membaca perenggan paling bawah atau footnote manual itu, tercatat bahawa

amalan menggunakan "break" atau "break-break" dikala kecemasan yang melibatkan nyawa adalah tidak disarankan sama sekali kerana ia tidak mengandungi maksud yang tidak difahami oleh semua orang. standard antarabangsa seperti "mayday" mesti digunakan untuk mengumumkan trafik kecemasan yang melibatkan nyawa.


tiada ayat yang mengatakan penggunaan "break" adalah mandatori untuk kecemasan yang melibatkan nyawa dalam prosidur suara dan tiada ayat mengatakan bahawa "BK" adalah mandatori untuk kecemasan yang melibatkan nyawa dalam prosidur morse.

oleh itu, elakkan dari menggunakan perkataan yang akan mengelirukan orang lain, gunalah bahasa ringkas dan jelas. Jikalau terjadi kecemasan yang berkeutamaan rendah, tidak melibatkan nyawa lebih baik breaking in dengan break atau callsign sahaja. radio amatur seharusnya berfikiran terbuka, dan tidak berpaut pada pegangang atau catatan orang lain yang bukan dari mana-mana wakil atau institusi yang disahkan seperti IARU dan juga ITU. Ada di antaranya rajin menulis manual dan juga tatatertib prosidur suara, sebagai radio amatur yang sentiasa kelaparan ilmu dan juga pengalaman, kita semestinya berfikir ketika berlakunya sesuatu keadaan dan tidak boleh melatah serta taksub akan sesuatu perkara. jika anda 9W, jangan mudah percaya kepada setiap ungkapan dari 9M, tidak semestinya apa yang keluar dari mulut 9M itu betul mengikut prosidur ataupun tatacara dari IARU atapun ITU. kita seharusnya mengambil dalam untuk mengkaji setiap apa yang kita baca dan jangan terimanya bulat-bulat dan terus taksub. tepuk dada tanya selera.

di dalam singkatan morse code, break atau BK membawa maksud, berhenti seketika dalam penghantaran mesej selalunya digunakan untuk mencelah,  atau ingin mendapatkan jawapan dengan segera. jika anda pernah beroperasi CW di 20 meter band, anda akan mendengar ada station yang akan menjawab CQ call anda dengan BK DE ______ . bukanlah bermaksud kecemasan ataupun distress call. jika anda taksub dengan perkataan break, break ini, cuba fikirkan kembali jikalau anda di dalam kecemasan dan anda menghantar morse code, BK BK BK DE 9W2XXX, adalah station yang lain akan faham ?

what you eat is what you are, apa yang anda baca akan membentuk diri anda sekarang. oleh itu pilih dan banding lah jika hendak membaca atau dengar.

adalah lebih elok jika berlakunya kecemasan, kita semua menggunakan bahasa atau perkataan yang mudah difahami oleh semua orang termasuk mereka yang bukan operator radio amatur. tidak menjadi kesalahan sebagai contoh, "INI ADALAH PANGGILAN KECEMASAN". kerana objektifnya panggilan kecemasan adalah untuk memohon untuk bantuan kecemasan yang bukan melibatkan nyawa seperti sesat jalan, tayar pancit  dan bukanlah untuk bergaya dalam bercakap ataupun menarik perhatian orang lain tanpa motif.

jika anda mendengar panggilan kecemasan, anda haruslah terus menuju kepada pemanggil tersebut dan jangan melengahkannya. jangan sesekali berkata, "station yang dalam kecemasan sila tunggu sebentar, kerana saya ini ragchew dengan rakan karib saya".

station yang mendengar haruslah berhenti dari memancar, dan jangan masuk jika anda tidak diperlukan. jika relay station diperlukan, anda boleh masuk mengikut prosidur. pada masa kecemasan, amalan dan praktikal KEEP IT SHORT AND SIMPLE adalah mustahak, kerana kita tidak tahu mungkin dalam masa satu saat boleh berlaku kemusnahan ataupun kematian.

dalam bentuk operasi suara, jika anda memanggil untuk panggilan kecemasan, gunakanlah standard antarabangsa iaitu "MAYDAY", ini adalah panggilan kecemasan yang melibatkan nyawa.

dalam operasi morse code ataupun CW, anda mesti menghantar "SOS" sebagai satu karakter, bukan S O S, tetapi SOS. tiada spacing atau ruang di antara ketiga huruf. jika anda menghantar "BK BK BK DE 9M2___", adakah satu dunia faham apa yang anda cuba sampaikan ?


please watch this video first.

A proword is short for procedure word, or phrase. MAYDAY is the proword for an emergency/distress call. OVER is a proword to signify that you've ended transmission and expect a reply.

ROGER or AFFIRMATIVE is a proword signifying that you understand, and or copied the last transmission clearly.

The first voice was a station calling for the station who called emergency call earlier and he keep repeating the "mayday, mayday" words.

The 2nd voice from the other station who broke in was asking him to stop repeating MAYDAY on the air because it would cause problems with others listening.

Because, repeating the proword "Mayday" can confusing other stations listening in for emergency traffic. In this instance, with poor signal conditions, only the station in distress should use the prosign 'mayday'.

Siapakah Station Master ?

Tahukah anda bahawa, jika sesuatu callsign event atau kelab dikeluarkan memerlukan station master untuk beroperasi ?

Apakah itu station master ?

  1. station master adalah orang yang memegang callsign kelas A ataupun extra class (mengikut pengelasan negara masing-masing) yang masih sah dan mempunyai ilmu pengetahuan dalam telekomunikasi, undang-undang peringkat wilayah IARU, undang-undang negara, mampu mendemonstrasikan teori teknikal dan juga praktikal, mempunyai amalan dan teori prosidur pengeoperasian yang betul dan yang paling penting adalah memahami konsep radio amatur.
  2. station master juga mestilah bertanggungjawab, sebagai contoh, jika operasi SSB di high frekuensi, station master perlu mendidik operator yang lain akan cara dan prosidur yang sepatutnya dilakukan dan yang harus dielakkan. 
  3. station master perlu tau apa itu panggilan kecemasan ataupun distress call. station master perlulah dari mereka yang kenal apa itu "mayday, mayday", "pan, pan" dan juga morse code "... --- ...".
  4. station master perlu tahu apa itu base station, mobile, portable station, maritime mobile, parachute mobile, human portable dan juga stationary mobile.
  5. jika station master masih bingung dan tidak faham apa itu "break" atau  morse code "BK", mereka haruslah merujuk kepada undang-undang, tatacara dan juga guidelines pada peringkat IARU sendiri. kadangkala guidelines peringkat negara tidak sezaman dengan apa yang ditulis pada peringkat IARU. harus diingat bahawa, bila beroperasi di high frekuensi, isyarat yang dipancarkan tiada sempadan negara. malahan satu dunia boleh menerima isyarat yang dipancarkan.
  6. station master perlu membimbing mereka yang masih baru dalam radio amatur, persiapan seperti pertunjukan cara penggunaan peralatan radio, skrip untuk prosidur suara adalah sangat penting bagi mengelakkan keadaan yang tidak diingini. 
  7. station master mestilah mengetahui dan mampu melaksanakan apa jua operasi radio seperti SSB, CW dan juga digital,  bila berlaku sebarang kecemasan dan memerlukan komunikasi bantuan kecemasan, peralatan tambahan seperti antenna tuning unit, linear amplifier, full wave antenna sangat berguna.jika microphone rosak, station master perlu tau operasi dan juga prosidur dalam operasi bentuk morse code.
  8. station master juga perlulah dari mereka yang sentiasa tahu akan perubahan undang-undang di peringkat negara dan juga di peringkat wilayah IARU. contohnya, jika berlaku sebarang bencana alam di Jepun, beberapa frekuensi akan dikhaskan untuk proses bantuan bencana alam. jadi, station master di Malaysia haruslah tahu apa perkembangan terkini yang berlaku supaya tidak berlaku kekeliruan dan juga kekacauan nanti.
  9. station master juga mestilah dari mereka yang sentiasa memperlengkapkan diri dengan ilmu yang seharusnya seseorang radio amatur tahu seperti draft spektrum dari pihak authority, notis bandplan dari IARU wilayah, teori pembuatan antenna, teori propagasi, tatacara penggunaan radio (manual) dan lain-lain.
  10.  "mendengar dahulu sebelum bercakap" adalah satu amalan yang bagus. jika anda orang Melayu, sudah tentu anda faham apa itu ungkapan "cakap siang pandang-pandang, cakap malam dengar-dengar"
  11. station master seharusnya dari mereka yang mengamalkan K.I.S.S (keep it short and simple) method. jika anda menggunakan sumber kuasa yang terhad seperti bateri, amalan ini adalah bagus kerana sumber tenaga yang terhad, dengan short and simple operation anda tidak membazir tenaga. jika bercakap terlalu berbunga, banyak selingan dengan perkara yang tidak penting selalunya membawa kepada penghantaran mesej yang tidak jelas terutama jika keadaan frekuensi yang tidak bagus seperti noise, interference dan lain-lain.
  12. station master perlu ada disamping operator lain pada setiap masa operasi dan tidak boleh menyerahkan tugas kepada orang lain ini adalah kerana, jika berlaku perkara yang operator sampingan tidak mampu menyelesaikannya, station master perlu bertanggungjawab. sebagai contoh, dalam pertengahan komunikasi, tiba-tiba terdengar morse code "... --- ..." dengan kuat dan operator yang tidak tahu akan perkara ini, station master perlulah mengambil alih station dengan segera.
  13. station master seharusnya tahu untuk membuat antenna ringkas dari bahan yang ada di sekitar tapak station. jika berlaku kerosakan antenna, dan mesej yang penting harus dihantar, station master perlu mengambil langkah untuk membina antenna baru supaya mesej yang penting itu dapat dihantar. 
  14. station master mesti peka kepada keadaan sekeliling, jika berlaku cuaca yang tidak bagus untuk operasi. station master berhak untuk mengarahkan station itu ditutup sementara demi keselamatan peralatan dan juga nyawa operator yang lain.
  15. jika station itu beroperasi di high frequency, station master perlu tahu bahasa inggeris. ini adalah kerana bahasa inggeris adalah bahasa radio amatur dan juga bahasa international. kebanyakkan manual peralatan radio itu sendiri ditulis di dalam bahasa inggeris dan bukanlah di dalam bahasa melayu.
  16. station master memerlukan operator radio amatur yang terdiri dari kelas tertinggi dan layak menggunakan semua frekuensi yang dibenarkan kepada amatur dengan jumlah kuasa yang telah ditetapkan. sesetengah negara memerlukan beberapa ujian untuk membolehkan seseorang itu mendapat kelas tertinggi. sebagai contoh, ada beberapa negara yang memerlukan ujian teori bertulis, dan juga praktikal dalam pengendalian peralatan radio dan ada juga negara masih yang mengekalkan ujian morse code. ada juga beberapa negara yang menerima educational dan juga profesional qualification dalam bidang eletrikal dan juga eletronik seperti ijazah ataupun diploma.

"The granting of a separate license to a club or organization generally requires that an individual with a current and valid amateur radio license, who is in good standing with the telecommunications authority, assumes responsibility for any operations conducted under the club license or club call sign."

Blackspade Microphone Giveaway

Checkout their contest here

Friday, October 14, 2011

What Do I Think About QRP ?

QRP means low power, low powered station. it can be a question, answer or a statement.

What do i think about QRP operation ?


  1. you can save your power source
  2. required no large space for the equipment
  3. safe condition to tune your radio to the antenna, so the reflected power will be less reflected to your radio
  4. enough for CW operation
  5. to test your newly build antenna
  6. new experience trying on the lowest power and how far you can good. you need to jot all the info such as solar flux, sun spots, antenna, geographical area, humidity, moisture, surrounding area and etc for further studies.

  1. you cant go anywhere when the band condition is bad. just hope for the magic happens.
  2. if you are on SSB, sometimes people will be not listening to your signal
  3. some said that "it is 1mw per miles", so if you are running on QRP all you can do is wait for the good propagation and magic will be happen.
  4. for emergency operation, power is critical. if you are calling for help on QRP radio, some people will hear you and some people will not hear you. all you can do is pray.
  5. you need to have a proper antenna tu radiate your signals. quad is better i think.
  6. proper grounding needed.
  7. you need to make a cable loss check to make sure your QRP transmission are truly transmitted, else you signal will be loss on you transmission cables.
  8. some people who live in a good soil conductivity places will giving you a good report on the operation. if you are living in a city, surrounded with transmitting towers, power lines your report will be not the same. 
  9. if you are on SSB mode, i think a pre-amp will help to boost your voice to your radio.
  10. you need to operate at good place for better result. where less interference, power lines, metals, etc.
High frequendy operation is not like VHF operation, you rely on the propagation, your surrounding area, you equipment and etc. There is not somekind of skills can improve this thing, skills is not like that "got money, buy a radio, wait for the band open and transmitting low power". skills is like, how you build you antenna, how you make your proper grounding system, and how you manage the pile up stations. Maybe i'm not a perfect writer, i think i left some words here. if you know, please comment and share what you think.

It is all about you, and it is all good. Amateur radio is a unique hobby, some said that amateur radio is a serious business.

Main Radio Cara Kampung

i heard someone on the amateur radio repeater station last month, saying that "kita main radio cara kampung je"

i would like to recall their statement here,

you all need to make up your mind. We are Malaysian amateur radio operator, not a commercial or just what you said that, "main radio cara kampung". If you are a class A or class B Malaysian amateur radio operator, that will mean to the world that you are Malaysian . So you need to behave, and try to solve something, arguments or whatever in the profesional way, not the "kampung" way.

No matter how "kampung" you live, mostly everyone are from kampung. Before the city, must be a kampung first. i try to make you understand that underestimating yourself or oneself are not good. no matter how.

we learn from our first education institution, which is our home. dad and mummy are our first teacher. if you are behaving like unpolite to the people, you are showing that how bad your dad and mummy are. easy, dont mad at me. this is true.

we are living our lives, so dont be so harsh to others. All of Malaysian amateur radio operator clubs not educating their members to be so harsh to others. For example, if you are an ASTRA's member, if you are talking bad to other club members, this will displaying to others that ASTRA's members is not good treating other amateur radio station. Just for example, i didnt mean that ASTRA's members are that bad.

so people, please make up you mind. think and rethink before you make any statement on the air. if you are transmitting bad words on VHF repeaters, our neighbor also can hear us. we can expect what they will say about us, Malaysian amateur radio operator. No matter which club you are, which country or which region, we are sharing the same frequency. be polite, and show to the world that we are the best amateur radio operator too.

just a little words from me.

Tuesday, October 11, 2011

W1S - Remembering Steve Jobs Special Event Callsign

QRZ.com page - http://www.qrz.com/callsign/W1S
Wikipedia - http://en.wikipedia.org/wiki/Steve_Jobs

Steve Jobs, the man who changed to world passed away. There a few United States ham radio operator who remember him and apply for a special event callsign. If you heard them on the bands, please give your call.

My condolences  wishes to Steve's family. R.I.P Steve.

Murder of Junko Furuta

"A high-school girl was abducted by four teen aged hooligans while she was on her way to work. They took her to the house of a friend, held her in his bedroom, and for the next forty-five days enacted every imaginable form of abuse on her (and some you wouldn't want to imagine). They gang-raped her—both with their own bodies and with an assortment of foreign objects—beat her, kicked her, doused her extremities with lighter fluid and set her on fire, and probably did many other things to her that went undocumented by either her tormentors or the police. They mocked her pain. They held her down and dropped barbells on her stomach. This last bit of torture was more than she could withstand, and after going into convulsions she apparently either strangled on her own vomit or simply died from her beatings. When the boys were questioned later about why they didn't do anything during her seizure, they replied, “We assumed she was faking it.”

"She tried to escape, more than once. The first time, she was caught in the process of making a phone call. The second time, she ran into the parents of the boy who lived there; apparently they had known all along what was gong on. She begged them to help her, but they refused; his friend had criminal connections, and they didn't want to get into trouble, too. After her death, they taped her arms and legs together, threw her into a 55-gallon drum, filled it with cement, and dumped it in an empty lot. The body wasn't recovered until almost a year later. The ringleader of the whole incident served eight years in prison and is now a free man."

DAY 1: November 22, 1988: Kidnapped
Kept captive in house, and posed as one of boy’s girlfriend
Raped (over 400 times in total)
Forced to call her parents and tell them she had run away
Starved and malnutritioned
Fed cockroaches to eat and urine to drink
Forced to masturbate
Forced to strip in front of others
Burned with cigarette lighters
Foreign objects inserted into her vagina/anus

DAY 11: December 1, 1988: Severely beat up countless times
Face held against concrete ground and jumped on
Hands tied to ceiling and body used as a punching bag
Nose filled with so much blood that she can only breath through her mouth
Dumbbells dropped onto her stomach
Vomited when tried to drink water (her stomach couldn’t accept it)
Tried to escape and punished by cigarette burning on arms
Flammable liquid poured on her feet and legs, then lit on fire
Bottle inserted into her anus, causing injury

DAY 20: December10, 1989: Unable to walk properly due to severe leg burns
Beat with bamboo sticks
Fireworks inserted into anus and lit
Hands smashed by weights and fingernails cracked
Beaten with golf club
Cigarettes inserted into vagina
Beaten with iron rods repeatedly
Winter; forced outside to sleep in balcony
Skewers of grilled chicken inserted into her vagina and anus, causing bleeding

DAY 30: Hot wax dripped onto face
Eyelids burned by cigarette lighter
Stabbed with sewing needles in chest area
Left nipple cut and destroyed with pliers
Hot light bulb inserted into her vagina
Heavy bleeding from vagina due to scissors insertion
Unable to urinate properly
Injuries were so severe that it took over an hour for her to crawl downstairs and use the bathroom
Eardrums severely damaged
Extreme reduced brain size

DAY 40: Begged her torturers to “kill her and get it over with”

January 1, 1989: Junko greets the New Years Day alone
Body mutilated
Unable to move from the ground

DAY 44: January 4, 1989: The four boys beat her mutilated body with an iron barbell, using a loss at the game of Mah-jongg as a pretext. She is profusely bleeding from her mouth and nose. They put a candle’s flame to her face and eyes.

Then, lighter fluid was poured onto her legs, arms, face and stomach, and then lit on fire. This final torture lasted for a time of two hours.

Junko Furuta died later that day, in pain and alone. Nothing could compare 44 days of suffering she had to go through.

When her mother heard the news and details of what had happened to her daughter, she fainted. She had to undergo a psychiatric outpatient treatment . Imagine her endless pain.

Her killers are now free men. Justice was never served, not even after 20 years.
They deserve a punishment much greater than they had put upon Furuta, for putting an innocent girl through the most unbearable suffering.

This story from 1989 is true. Please spread her story around. Everyone should know about the existence of Junko Furuta’s unimaginable and incomprehensible suffering, and this is why this group has been made.

Tell this story to your friends. Never let her story be forgotten. If this story changes the life of at least one person then it has been worth it.

Rest In Eternal Peace, Junko Furuta

For more info, please read at http://en.wikipedia.org/wiki/Furuta_Junko


Monday, October 10, 2011

Cadangan Untuk Malaysian CW Net

Sekadar cadangan, perlu dikajiselidik semula.

Kepada mereka yang berkenaan, sila komen sebagai maklumbalas.

Terdapat beberapa sifat net, samada assisted net, directed net ataupun round robin net. Radio amatur biasanya menjalankan beberapa jenis net. Di dalam assisted net, stesyen tidak dibenarkan untuk break in begitu sahaja, memanggil stesyen lain tanpa arahan dari net control station (NCS). Kecuali jika terdapat sebarang kecemasan atau pun mesej yang berkeutamaan tinggi.

Jenis-jenis net:-
  1. Trafik - bertujuan untuk menyampaikan berita atau mesej dari satu stesyen kepada semua stesyen.Selalunya dilakukan sebagai rutin bertujuan untuk berlatih dalam penyampaian mesej pada waktu yang diperlukan dan juga pada waktu kecemasan atau bencana. Net ini bersifat sebagai khidmat masyarakat di mana mesej yang dirasakan perlu diberitahu kepada semua boleh disebarkan ketika net dijalankan.Net ini juga dapat memeriksa keadaan peralatan komunikasi radio amatur adakah dalam keadaan yang memuaskan ataupun tidak secara tidak lansung menjadi tempat pertemuan radio amatur.
  2. DX - suatu net di mana satu stesyen berhubung dengan satu stesyen yang jauh bertujuan menambah contact, menguji peralatan dan juga keadaan propagasi. Ketika net ini dijalankan, stesyen dari beberapa buah negara akan dapat berhubung, berkenalan dan juga dapat menyampaikan mesej kepada stesyen dari negara yang lain.
  3. Topik Khas - Net ini bertujuan untuk mengumpulkan operator radio amatur pada satu-satu masa bertujuan untuk membincangkan sesuatu topik khas berkenaan peralatan komunikasi, cuaca ataupun sebarang perkara tertentu demi menggalakan aktiviti radio amatur.

CW ataupun continuous wave adalah salah satu mod pancaran gelombang radio. Cadangan untuk Malaysian CW net adalah untuk menggalakkan, mempromosikan kod Morse kepada semua operator radio amatur di Malaysia. Kelajuan yang dicadangkan adalah sekitar 8wpm ke 14wpm mengikut kesesuaian net control station.

Prosidur untuk Malaysian CW net

  1. Net control station (NCS) akan menjalankan net ini pada frekuensi tertentu pada waktu yang akan ditetapkan.
  2. NCS perlu menghantar "QRL? QRL? QRL? DE 9M2PJU K" dan perlu memastikan tiada stesyen lain sedang menggunakan frekuensi itu.
  3. NCS akan memanggil dengan "CQ MY NET CQ MY NET CQ MY NET DE 9M2PJU/NCS K"
  4. Selepas memanggil, NCS perlu berhenti seketika untuk mendengar sahutan dari stesyen-stesyen yang lain.
  5. Stesyen yang menyahut perlulah menghantar callsignnya, sebagai contoh "DE 9M2AR 9M2AR K"
  6. NCS perlu mengulang balik callsign stesyen yang menyahut, "9M2AR DE 9M2PJU/NCS PSE K"
  7. Stesyen yang menyahut tadi akan menjawab dengan "9M2PJU/NCS DE 9M2AR QNI" bermaksud "di sini 9M2AR checking in"
  8. NCS akan menjawab dengan "9M2AR DE 9M2PJU ANY MSG ? BK" bermaksud "9M2AR di sini 9M2PJU ada sebarang mesej ? break". Jika ada, sila hantar mesej berkenaan.
  9. Jika tiada, NCS akan meminta stesyen 9M2AR untuk standby di frekuensi, "9M2AR DE 9M2PJU/NCS AS"
  10. NCS akan memanggil balik "CQ MY NET CQ MY NET CQ MY NET DE 9M2PJU/NCS K" dan proses menyahut dan menjawab sahutan berulang kembali sehingga net tamat.
  11. Untuk menamatkan net, NCS akan menghantar "MY NET NOW QNF 73 DE 9M2PJU SK E E"
Antara Q-Codes yang digunakan,

● QRL - as, QRL? - is the frequency busy or in use?
● QRS - Shall I send more slowly
● QRZ - Who is calling me
● QSB - Are my signals fading
● QSY - Shall I change to to transmission on another frequency
● QTH - What is your location? My location is
● QNI - Call for net stations to report or check in
● QNP - Unable to copy you
● QNF - The net is free/over

Prosigns dan singkatan,

● C Q - Calling any station
● D E - from
● K - go (over), invite any station to transmit
● KN - go only, invite a specific station to transmit
● BK - invite receiving station to transmit
● R - all received OK
● AS - please stand by
● SK - end of contact (sent before call)
● E S – and
● U R – your
● BT - a pause, like saying “uH” in a conversation
● P S E – please
● R I G – equipment, my equipment
● T N X – thanks or T U – thank you
● U R – your
● G U D – good
● H I – Ha Ha
● W X – weather
● 7 3 – best regards

Build Your Foxhole Radio

During World War II, GIs in the field built really amazing simple radios to listen
too. These were made with materials that they could get their hands on and were
small enough to carry around in a big pocket. You can modify this design if you
want to set it up so that it’s tuneable too!

This project is similar to a simple crystal radio but crystals were hard to get ahold
of for the soldiers and so they made do. Radio making runs in my family. My
Grandpa Charlie made his own radios in the 30s and during the war as well. In
fact, in a recent email, he mentioned that they were encouraged to make radios and
“learn by doing.” Radios were the hottest technology of the time and after the
exhilaration of getting this radio work, I can understand!

You may not be able to get it to work at the first hookup. I had problems with my
razor blade and then also had problems getting the ground the wire attached tightly
enough to the radiator to make a grounding connection.


There aren’t many safety issues here except for lightning and fire and the razor
blades. Never put an antenna up in a storm. There are lots of stories on the
internet about radio enthusiast’s projects getting struck by lightning. Also, for this
project I used a propone torch to blue my razor blade. Take all the safety
precautions necessary to avoid burning and cutting yourself. You’re responsible
for your own safety!


• Toilet paper tube
• Razor blade (If you can find a Blue one like the “PAL Super Single Edge”
then great. Otherwise, you’ll have to blue it by heating it up)
• Earphone
• Large safety pin
• Wood pencil stub
• Magnet wire
• A scrap of wood
• Paper clips
• Tacks

Make it!

The Coil – I made this with magnet wire I had lying around. I’ve seen radios made
with really thin wire, like I used, to thicker wire almost as thick as a staple. I used
tape to hold it to the cardboard tube, but in retrospect, poking a hole and tying it on
would be better. Wrap the wire around the tube 120 times and take time to make it
smoosh together. I kept getting distracted from counting, so I ended up counting
after winding. If it’s not exact, it shouldn’t be a problem. The amount of coils
does matter for the radio station. If you get a station in sorta good, but it’s not
perfect, you may be able to correct that by adding extra loops.

The Detector – Soldiers were given blued razor blades as part of their supplies.
The bluing is some sort of oxidized coating from getting heated up, it probably
keeps it sharper for longer. My research says that a rusted razor blade may work
too. For me, I blued it with a propane torch and when I wiped it off after it had
cooled, there was a layer of oxide on it and it was blue and purplish gray. I tried rusting a razor blade, but maybe it was stainless steel or something because it just
wouldn’t rust. Salt water would be the best way to do it, but I just wasn’t patient

The Cat Whisker – Take a pencil stubb and poke the graphite with a safety pin.
This works as a diode, but this is magic to me. If you can explain it simply, drop a
note in the comments!

Earphone – I used an old-school earphone from my bat detector project last year,
but if you don’t have one, I would try out the earphones you already have before
buying a new one.

Antenna – I stripped a cat6 cable and used one wire to hang out the window. My
wire is about 25 feet long, but longer is better!

Ground – I attached a wire onto the radiator. If you don’t have a radiator you
could drive a coat hanger into the ground and wind a wire to that.

 Hook it all together – I used brass tacks to keep it all together and paperclips to
connect all the wires.

 Making it work – The first time I tried this, it didn’t work. It was frustrating, but I
just went through my materials, blued the razor blade and it worked. The second
time I tried to get it to work, I couldn’t get a station, I just got buzz. I played with
everything and finally figured out that the ground connection wasn’t very good.

When I fixed that, I was able to hear sports talk radio! One of the interesting things
is that it works better or worse depending on where you put the pencil lead on the
razor blade. If it doesn’t work the first time, don’t give up! Every project you
work on can have 100% success as long as you don’t mind mistakes and redoing

from: http://cdn.makezine.com/make/wp_foxholeradio.pdf

Sunday, October 9, 2011


The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. A decibel is one tenth of a bel, a seldom-used unit.

The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory. In electronics, the gains of amplifiers, attenuation of signals, and signal-to-noise ratios are often expressed in decibels. The decibel confers a number of advantages, such as the ability to conveniently represent very large or small numbers, and the ability to carry out multiplication of ratios by simple addition and subtraction. The decibel symbol is often qualified with a suffix, that indicates which reference quantity or frequency weighting function has been used.

For example, dBm indicates a reference level of one milliwatt, while dBu is referenced to 0.775 volts RMS. The definitions of the decibel and bel use base 10 logarithms. The neper, an alternative logarithmic ratio unit sometimes used, uses the natural logarithm (base e). A change in power ratio by a factor of 10 is a 10 dB change. A change in power ratio by a factor of two is approximately a 3 dB change.


The decibel is commonly used in acoustics to quantify sound levels relative to a 0 dB reference which has been defined as a sound pressure level of .0002 microbar. The reference level is set at the typical threshold of perception of an average human and there are common comparisons used to illustrate different levels of sound pressure. As with other decibel figures, normally the ratio expressed is a power ratio (rather than a pressure ratio).
The human ear has a large dynamic range in audio perception. The ratio of the sound intensity that causes permanent damage during short exposure to the quietest sound that the ear can hear is greater than or equal to 1 trillion Such large measurement ranges are conveniently expressed in logarithmic units: the base-10 logarithm of one trillion (1012) is 12, which is expressed as an audio level of 120 dB. Since the human ear is not equally sensitive to all sound frequencies, noise levels at maximum human sensitivity—somewhere between 2 and 4 kHz—are factored more heavily into some measurements using frequency weighting. (See also Stevens' power law.)


In electronics, the decibel is often used to express power or amplitude ratios (gains), in preference to arithmetic ratios or percentages. One advantage is that the total decibel gain of a series of components (such as amplifiers and attenuators) can be calculated simply by summing the decibel gains of the individual components. Similarly, in telecommunications, decibels denote signal gain or loss from a transmitter to a receiver through some medium (free space, waveguide, coax, fiber optics, etc.) using a link budget.
The decibel unit can also be combined with a suffix to create an absolute unit of electric power. For example, it can be combined with "m" for "milliwatt" to produce the "dBm". Zero dBm equals one milliwatt, and 1 dBm is one decibel greater (about 1.259 mW).
In professional audio, a popular unit is the dBu (see below for all the units). The "u" stands for "unloaded", and was probably chosen to be similar to lowercase "v", as dBv was the older name for the same thing. It was changed to avoid confusion with dBV. This unit (dBu) is an RMS measurement of voltage which uses as its reference 0.775 VRMS. Chosen for historical reasons, it is the voltage level which delivers 1 mW of power in a 600 ohm resistor, which used to be the standard reference impedance in telephone audio circuits.


In an optical link, if a known amount of optical power, in dBm (referenced to 1 mW), is launched into a fiber, and the losses, in dB (decibels), of each electronic component (e.g., connectors, splices, and lengths of fiber) are known, the overall link loss may be quickly calculated by addition and subtraction of decibel quantities.
In spectrometry and optics, the blocking unit used to measure optical density is equivalent to −1 B.

Video and digital imaging

In connection with video and digital image sensors, decibels generally represent ratios of video voltages or digitized light levels, using 20 log of the ratio, even when the represented optical power is directly proportional to the voltage or level, not to its square, as in a CCD imager where response voltage is linear in intensity. Thus, a camera signal-to-noise ratio or dynamic range of 40 dB represents a power ratio of 100:1 between signal power and noise power, not 10,000:1.Sometimes the 20 log ratio definition is applied to electron counts or photon counts directly, which are proportional to intensity without the need consider whether the voltage response is linear.
However, as mentioned above, the 10 log intensity convention prevails more generally in physical optics, including fiber optics, so the terminology can become murky between the conventions of digital photographic technology and physics. Most commonly, quantities called "dynamic range" or "signal-to-noise" (of the camera) would be specified in 20 log dBs, but in related contexts (e.g. attenuation, gain, intensifier SNR, or rejection ratio) the term should be interpreted cautiously, as confusion of the two units can result in very large misunderstandings of the value.
Photographers also often use an alternative base-2 log unit, the f-stop, and in software contexts these image level ratios, particularly dynamic range, are often loosely referred to by the number of bits needed to represent the quantity, such that 60 dB (digital photographic) is roughly equal to 10 f-stops or 10 bits, since 103 is nearly equal to 210.

Suffixes are commonly attached to the basic dB unit in order to indicate the reference level against which the decibel measurement is taken. For example, dBm indicates power measurement relative to 1 milliwatt.
In cases such as this, where the numerical value of the reference is explicitly and exactly stated, the decibel measurement is called an "absolute" measurement, in the sense that the exact value of the measured quantity can be recovered using the formula given earlier. If the numerical value of the reference is not explicitly stated, as in the dB gain of an amplifier, then the decibel measurement is purely relative.
The practice of attaching a suffix to the basic dB unit, forming compound units such as dBm, dBu, dBA, etc., is not permitted for use with the SI. However, outside of documents adhering to SI units, the practice is very common as illustrated by the following examples.


Since the decibel is defined with respect to power, not amplitude, conversions of voltage ratios to decibels must square the amplitude, as discussed above.

A schematic showing the relationship between dBu (the voltage source) and dBm (the power dissipated as heat by the 600 Ω resistor)

dB(1 VRMS) – voltage relative to 1 volt, regardless of impedance]
dBu or dBv
dB(0.775 VRMS) – voltage relative to 0.775 volts. Originally dBv, it was changed to dBu to avoid confusion with dBV. The "v" comes from "volt", while "u" comes from "unloaded". dBu can be used regardless of impedance, but is derived from a 600 Ω load dissipating 0 dBm (1 mW). Reference voltage V = \sqrt{600 \, \Omega \cdot 0.001\,\mathrm W}\, \approx 0.7746\,\mathrm V
In professional audio, equipment may be calibrated to indicate a "0" on the VU meters some finite time after a signal has been applied at an amplitude of +4 dBu. Consumer equipment will more often use a much lower "nominal" signal level of -10 dBV. Therefore, many devices offer dual voltage operation (with different gain or "trim" settings) for interoperability reasons. A switch or adjustment that covers at least the range between +4 dBu and -10 dBV is common in professional equipment.

dB(1 mVRMS) – voltage relative to 1 millivolt across 75 Ω. Widely used in cable television networks, where the nominal strength of a single TV signal at the receiver terminals is about 0 dBmV. Cable TV uses 75 Ω coaxial cable, so 0 dBmV corresponds to −78.75 dBW (−48.75 dBm) or ~13 nW.
dBμV or dBuV
dB(1 μVRMS) – voltage relative to 1 microvolt. Widely used in television and aerial amplifier specifications. 60 dBμV = 0 dBmV.


Probably the most common usage of "decibels" in reference to sound loudness is dB SPL, sound pressure level referenced to the nominal threshold of human hearing:

dB (sound pressure level) – for sound in air and other gases, relative to 20 micropascals (μPa) = 2×10−5 Pa, the quietest sound a human can hear. This is roughly the sound of a mosquito flying 3 meters away. This is often abbreviated to just "dB", which gives some the erroneous notion that "dB" is an absolute unit by itself. For sound in water and other liquids, a reference pressure of 1 μPa is used.
One Pascal is equal to 94 dB(SPL). This level is used to specify microphone sensitivity. For example, a typical microphone may put out 20 mV at one pascal. For other sound pressure levels, the output voltage can be computed from this basis, except that noise and distortion will affect the extreme levels.

dB – relative to 1 Pa, often used in telecommunications.
dB sound intensity level – relative to 10−12 W/m2, which is roughly the threshold of human hearing in air.
dB sound power level – relative to 10−12 W.
dB(A), dB(B), and dB(C)
These symbols are often used to denote the use of different weighting filters, used to approximate the human ear's response to sound, although the measurement is still in dB (SPL). These measurements usually refer to noise and noisome effects on humans and animals, and are in widespread use in the industry with regard to noise control issues, regulations and environmental standards. Other variations that may be seen are dBA or dBA. According to ANSI standards, the preferred usage is to write LA = x dB. Nevertheless, the units dBA and dB(A) are still commonly used as a shorthand for A-weighted measurements. Compare dBc, used in telecommunications.
dB HL or dB hearing level is used in audiograms as a measure of hearing loss. The reference level varies with frequency according to a minimum audibility curve as defined in ANSI and other standards, such that the resulting audiogram shows deviation from what is regarded as 'normal' hearing.

dB Q is sometimes used to denote weighted noise level, commonly using the ITU-R 468 noise weighting

Audio electronics

dB(mW) – power relative to 1 milliwatt. No reference impedance is assumed, although 600 ohms is common in audio equipment.
dB(full scale) – the amplitude of a signal compared with the maximum which a device can handle before clipping occurs. Full-scale may be defined as the power level of a full-scale sinusoid or alternatively a full-scale square wave.
dB(true peak) - peak amplitude of a signal compared with the maximum which a device can handle before clipping occurs. In digital systems, 0 dBTP would equal the highest level (number) the processor is capable of representing. Measured values are always negative or zero, since they are less than or equal to full-scale.


dB(Z) – energy of reflectivity (weather radar), related to the amount of transmitted power returned to the radar receiver; the reference level for Z is 1 mm6 m−3. Values above 15–20 dBZ usually indicate falling precipitation.
dBsm – decibel measure of the radar cross section (RCS) of a target relative one square meter. The power reflected by the target is proportional to its RCS. "Stealth" aircraft and insects have negative RCS measured in dBsm, large flat plates or non-stealthy aircraft have positive values.

Radio power, energy, and field strength

dBc – relative to carrier—in telecommunications, this indicates the relative levels of noise or sideband peak power, compared with the carrier power. Compare dBC, used in acoustics.
dB(J) – energy relative to 1 joule. 1 joule = 1 watt per hertz, so power spectral density can be expressed in dBJ.
dB(mW) – power relative to 1 milliwatt. When used in the radio field, the dB is usually referenced to a 50 ohm load, with the resultant voltage being 0.224 volts. There are times when spec sheets may show the voltage & power level e.g. −120 dBm = 0.224 microvolts.
dBμV/m or dBuV/m
dB(μV/m) – electric field strength relative to 1 microvolt per meter. Often used to specify the signal strength from a television broadcast at a receiving site (the signal measured at the antenna output will be in dBμV).
dB(fW) – power relative to 1 femtowatt.
dB(W) – power relative to 1 watt.
dB(kW) – power relative to 1 kilowatt.

Antenna measurements

dB(isotropic) – the forward gain of an antenna compared with the hypothetical isotropic antenna, which uniformly distributes energy in all directions. Linear polarization of the EM field is assumed unless noted otherwise.
dB(dipole) – the forward gain of an antenna compared with a half-wave dipole antenna. 0 dBd = 2.15 dBi
dB(isotropic circular) – the forward gain of an antenna compared to a circularly polarized isotropic antenna. There is no fixed conversion rule between dBiC and dBi, as it depends on the receiving antenna and the field polarization.
dB(quarterwave) – the forward gain of an antenna compared to a quarter wavelength whip. Rarely used, except in some marketing material. 0 dBq = −0.85 dBi

Other measurements

dB(hertz) – bandwidth relative to 1 Hz. E.g., 20 dB-Hz corresponds to a bandwidth of 100 Hz. Commonly used in link budget calculations. Also used in carrier-to-noise-density ratio (not to be confused with carrier-to-noise ratio, in dB).
dBov or dBO
dB(overload) – the amplitude of a signal (usually audio) compared with the maximum which a device can handle before clipping occurs. Similar to dBFS, but also applicable to analog systems.
dB(relative) – simply a relative difference from something else, which is made apparent in context. The difference of a filter's response to nominal levels, for instance.
dB above reference noise.

Antenna diversity

Antenna diversity, also known as space diversity, is any one of several wireless diversity schemes that uses two or more antennas to improve the quality and reliability of a wireless link. Often, especially in urban and indoor environments, there is no clear line-of-sight (LOS) between transmitter and receiver. Instead the signal is reflected along multiple paths before finally being received. Each of these bounces can introduce phase shifts, time delays, attenuations, and distortions that can destructively interfere with one another at the aperture of the receiving antenna. Antenna diversity is especially effective at mitigating these multipath situations. This is because multiple antennas offer a receiver several observations of the same signal. Each antenna will experience a different interference environment. Thus, if one antenna is experiencing a deep fade, it is likely that another has a sufficient signal. Collectively such a system can provide a robust link. While this is primarily seen in receiving systems (diversity reception), the analog has also proven valuable for transmitting systems (transmit diversity) as well. Inherently an antenna diversity scheme requires additional hardware and integration versus a single antenna system but due to the commonality of the signal paths a fair amount of circuitry can be shared. Also with the multiple signals there is a greater processing demand placed on the receiver, which can lead to tighter design requirements. Typically, however, signal reliability is paramount and using multiple antennas is an effective way to decrease the number of drop-outs and lost connections.

The following classes of diversity schemes can be identified:
  • Time diversity: Multiple versions of the same signal are transmitted at different time instants. Alternatively, a redundant forward error correction code is added and the message is spread in time by means of bit-interleaving before it is transmitted. Thus, error bursts are avoided, which simplifies the error correction.
  • Frequency diversity: The signal is transmitted using several frequency channels or spread over a wide spectrum that is affected by frequency-selective fading. Middle-late 20th century microwave radio relay lines often used several regular wideband radio channels, and one protection channel for automatic use by any faded channel. Later examples include:
    • OFDM modulation in combination with subcarrier interleaving and forward error correction
    • Spread spectrum, for example frequency hopping or DS-CDMA.
  • Space diversity: The signal is transmitted over several different propagation paths. In the case of wired transmission, this can be achieved by transmitting via multiple wires. In the case of wireless transmission, it can be achieved by antenna diversity using multiple transmitter antennas (transmit diversity) and/or multiple receiving antennas (reception diversity). In the latter case, a diversity combining technique is applied before further signal processing takes place. If the antennas are far apart, for example at different cellular base station sites or WLAN access points, this is called macrodiversity or site diversity. If the antennas are at a distance in the order of one wavelength, this is called microdiversity. A special case is phased antenna arrays, which also can be used for beamforming, MIMO channels and Space–time coding (STC).
  • Polarization diversity: Multiple versions of a signal are transmitted and received via antennas with different polarization. A diversity combining technique is applied on the receiver side.
  • Multiuser diversity: Multiuser diversity is obtained by opportunistic user scheduling at either the transmitter or the receiver. Opportunistic user scheduling is as follows: the transmit selects the best user among candidate receivers according to the qualities of each channel between the transmitter and each receiver. In FDD systems, a receiver must feed back the channel quality information to the transmitter with the limited level of resolution.
  • Cooperative diversity: Achieves antenna diversity gain by using the cooperation of distributed antennas belonging to each node.
Antenna diversity can be realized in several ways. Depending on the environment and the expected interference, designers can employ one or more of these methods to improve signal quality. In fact multiple methods are frequently used to further increase reliability.

Spatial Diversity

Spatial diversity employs multiple antennas, usually with the same characteristics, that are physically separated from one another. Depending upon the expected incidence of the incoming signal, sometimes a space on the order of a wavelength is sufficient. Other times much larger distances are needed. Cellularization or sectorization, for example, is a spatial diversity scheme that can have antennas or base stations miles apart. This is especially beneficial for the mobile communication industry since it allows multiple users to share a limited communication spectrum and avoid co-channel interference.

Pattern Diversity

Pattern diversity consists of two or more co-located antennas with different radiation patterns. This type of diversity makes use of directive antennas that are usually physically separated by some (often short) distance. Collectively they are capable of discriminating a large portion of angle space and can provide a higher gain versus a single omnidirectional radiator.

Polarization Diversity

Polarization diversity combines pairs of antennas with orthogonal polarizations (i.e. horizontal/vertical, ± slant 45°, Left-hand/Right-hand CP etc.). Reflected signals can undergo polarization changes depending on the medium through which they are travelling. A polarisation difference of 90° will result in an attenuation factor of up to 34dB in signal strength. By pairing two complementary polarizations, this scheme can immunize a system from polarization mismatches that would otherwise cause signal fade. Additionally, such diversity has proven valuable at radio and mobile communication base stations since it is less susceptible to the near random orientations of transmitting antennas.

Transmit/Receive Diversity

Transmit/Receive diversity uses two separate, collocated antennas for transmit and receive functions. Such a configuration eliminates the need for a duplexer and can protect sensitive receiver components from the high power used in transmit.

Adaptive Arrays

Adaptive antenna arrays can be a single antenna with active elements or an array of similar antennas with ability to change their combined radiation pattern as different conditions persist. Active electronically scanned arrays (AESAs) manipulate phase shifters and attenuators at the face of each radiating site to provide a near instantaneous scan ability as well as pattern and polarization control. This is especially beneficial for radar applications since it affords a signal antenna the ability to switch among several different modes such as searching, tracking, mapping and jamming
In radio, multiple-input and multiple-output, or MIMO (commonly pronounced my-moh or me-moh), is the use of multiple antennas at both the transmitter and receiver to improve communication performance. It is one of several forms of smart antenna technology. Note that the terms input and output refer to the radio channel carrying the signal, not to the devices having antennas.
MIMO technology has attracted attention in wireless communications, because it offers significant increases in data throughput and link range without additional bandwidth or transmit power. It achieves this by higher spectral efficiency (more bits per second per hertz of bandwidth) and link reliability or diversity (reduced fading). Because of these properties, MIMO is an important part of modern wireless communication standards such as IEEE 802.11n (Wifi), 4G, 3GPP Long Term Evolution, WiMAX and HSPA+.

Saturday, October 8, 2011

What Is Decibel ?

The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Your ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. In terms of power, the sound of the jet engine is about 1,000,000,000,000 times more powerful than the smallest audible sound. That's a big difference!
On the decibel scale, the smallest audible sound (near total silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound 100 times more powerful than near total silence is 20 dB. A sound 1,000 times more powerful than near total silence is 30 dB. Here are some common sounds and their decibel ratings:
  • Near total silence - 0 dB
  • A whisper - 15 dB
  • Normal conversation - 60 dB
  • A lawnmower - 90 dB
  • A car horn - 110 dB
  • A rock concert or a jet engine - 120 dB
  • A gunshot or firecracker - 140 dB
You know from your own experience that distance affects the intensity of sound -- if you are far away, the power is greatly diminished. All of the ratings above are taken while standing near the sound.
Any sound above 85 dB can cause hearing loss, and the loss is related both to the power of the sound as well as the length of exposure. You know that you are listening to an 85-dB sound if you have to raise your voice to be heard by somebody else. Eight hours of 90-dB sound can cause damage to your ears; any exposure to 140-dB sound causes immediate damage (and causes actual pain).

Vintage QSL Cards From Malaya

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