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Saturday, October 27, 2012

How to select the operating mode of TP-LINK wireless multiple modes devices?


Suitable for: TL-MR3020, TL-MR3040, TL-WA5110G, TL-WA5210G, TL-WA7510N, TL-WR543G, TL-WR700N, TL-WR702N, TL-WR743ND
Some TP-LINK devices have multiple operating modes, such as AP/ Wireless Router/ Repeater/ Bridge/ Client/ AP Client Router. You may be confused about which mode I should use. Here is an article explains how each mode works to help you make a decision.
 
1.    AP Mode(for hotel Internet extension)
AP mode is more used to transfer wired connection into wireless. It works like a switch. Usually, it is behind a router.
If you are in an office, hotel and places where only wired network is available, or LAN gaming party, small meeting and other situations where a temporary wireless network is needed, please use the AP Mode.
 
2.    Wireless Router Mode(for home Internet sharing)
With the router mode, it can share one wired Internet connection to several clients. At that time, there will be one WAN port. It supports multiple connection types, like Dynamic IP/Static IP/PPPoE/L2TP/PPTP.
When Internet access from DSL or cable modem is available for one user but more users need to share the Internet, please use the Router Mode.
 
3.    Repeater mode(for home Wi-Fi extension)
Repeater mode is used to extender the wireless coverage with same SSID and security.
When you have a wireless already, and there is some place can’t be covered, you can consider Repeater Mode. With Repeater mode, you will have only one SSID. At that time, your wireless clients can roam in whole place.
 
4.    Bridge Mode(for home or business networking)
Bridge mode borrows existing wireless Internet and broadcasts it using a different network name (SSID) and password. This application can create two individual networks for two groups of users sharing one Internet.
For small restaurant, bar, home, office and others where Internet service needs to be provided for guests without revealing the password of the existing network for hosts, Bridge Mode is the best choice.
 
5.    Client Mode(for home gaming console)
With client mode, it can connect to a wired device and works as a wireless adapter to receive wireless signal from your wireless network.
For a Smart TV, Media Player, or game console with an Ethernet port. Use the Client Mode to make your devices Wi-Fi enabled, granting them access to your wireless network.
 
6.    AP Client Router Mode(for WISP user Internet sharing)
With AP client router mode, it can connect to a wireless network and share the connection to its clients. The wireless is its WAN side. It can also support Dynamic IP/Static IP/PPPoE/L2TP/PPTP.
When the wireless station limits the number of clients or asks username/password to connect, AP Client Router Mode is what you need.

Mudiak Arau - Guitar Strumming

Teratai - Sweet Charity (Guitar Cover)

Thursday, October 25, 2012

9M2PJU's HF Portable Station At Bukit Keluang

1941 Morse Code Class

Kuala Lumpur Remote Control Cars

9M2PJU CW Dxing on 20m band

9M2AR And 9M2RB On 7.043 MHz

Bersiar-siar Di 40m Band

Patah Seribu - Sheila Hamzah (Guitar Plucking And Strumming)

Father And Son - Yusuf Islam (Formerly Known As Cat Steven)

Green Green Grass Of Home - Tom Jones (Guitar Strums)

A Mi Manera (Spanish Version Of My Way - Frank Sinatra) Instrumental Gui...

Aku Suka Dia - Ainan Tasneem (Original) Video Respond

Stay - Estrella (Guitar)

Anak Kampung - Jimmy Palikat (Guitar Cover) Video Respond

Tasha Manshahar - Be Mine (Original) Video Respond

Sentuhan Listrik Mu M. Nasir Guitar Cover

9M2AR And 9M2ZN High Speed CW QSO

9M2PJU 500mW QRP CW QSO WITH 9M2AR USING YAESU FT817ND

9M2AR Morse Code Video

Magnetic Loop Antenna Test

DU9XO CQ DX On JRC NRD 545 DSP Receiver

9M2PJU QRP Operation With Yaesu FT817ND

Monday, October 22, 2012

9M4CJB Operated By 9W2JJF CW QSO

Pada malam 21 Oktober 2012, saya telah dikejutkan dengan satu panggilan telefon dari Zaki 9M2ZAK. Beliau bertanyakan samada saya berkelapangan atau tidak, mujurlah ketika itu saya tidak sibuk seterusnya saya bertanyakan kenapa?. Cikgu Zaki 9M2ZAK mengajak saya untuk ke udara dalam mode CW atau kod Morse untuk sesi latihan kepada bakal calon CW test 2-2012 iaitu Ustaz Illiyas 9W2JJF.

Setelah mencari frekuensi yang sesuai, saya berhenti di satu frekuensi yang tiada QRM, berikutan semua segmen bagi narrow bandwidth operation di 40m band telah digunapakai secara haram oleh lanun (lanun adalah istilah kepada mereka yang beroperasi tanpa kebenaran yang sah). Kebanyakan lanun beroperasi dalam mode single side band atau pendeknya SSB. Mereka memancar (transmit) dengan jumlah kuasa pancaran yang agak tinggi (lebih dari 100 watts). Ini menyebabkan gangguan kepada operator radio amatur yang ingin bekerja dalam mode CW pada narrow bandwidth portion. Saya beroperasi di frekuensi yang bukan center operation bagi lanun-lanun tersebut. Filter dan noise reduction perlu dipasang untuk keselesaan semasa beroperasi.

Setelah beberapa transmission, saya berhenti seketika dan selepas itu saya sempat CW QSO dengan Cikgu Rahman 9M2AR di frekuensi tersebut. Beliau memaklumkan yang beliau baru balik dari makan malam. Saya memberitahu beliau akan sesi latihan untuk 9W2JJF akan disambung semula dan selepas itu Cikgu Rahman 9M2AR memberikan kami laluan.

Di bawah adalah video yang sempat dirakamkan oleh Zaki 9M2ZAK, di mana di dalam video ini menunjukkan 9W2JJF sedang ke udara dengan menggunakan callsign 9M4CJB sambil dipantau oleh 9M2ZAK.




Sifat dan kesungguhan 9W2JJF harus dipuji kerana beliau berusaha untuk mendapatkan sesuatu yang beliau inginkan. 9M2ZAK juga memainkan peranan penting dalam sesi pembelajaran kod Morse Ustaz Illiyas 9W2JJF. Sesungguhnya di mana ada kemahuan, di situ ada jalan. Hendak seribu daya, tak nak seribu dalih. Semoga berjaya menempuhi CW test 2-2012 yang akan tiba kepada 9W2JJF. Jumpa lagi di udara!

73 de 9M2PJU


Saturday, October 20, 2012

9M2PJU CW QSO With Ali A71CV


Keadaan 40m band agak bising ketika ini, tetapi saya berjaya berhubung dengan Ali dari Qatar dengan report 579.

Bersiar-siar di 40m Band

Mesej Tersembunyi (Morse Code) Dalam Lagu

Di Colombia, polis dan askar yang diculik dan ditahan oleh gerila FARC selama 12 tahun lebih hanya dibenarkan untuk mendengar berita dan juga muzik tertentu di radio. Pihak DDB Colombia dengan kerjasama tentera Colombia telah mencipta satu lagu yang mengandungi mesej tersembunyi (hidden message). Rentak yang sebenarnya pada chorus lagu itu adalah kod MORSE, memberitahu tentang berapa orang mangsa tahanan telah diselamatkan dan mereka juga akan diselamatkan nanti. Ini penting untuk mengembalikan moral tahanan yang telah lama ditahan pihak gerila.


"The Code" - Lagu ini telah ke udara selama 2 bulan lebih di 100 stesen radio berlainan merentasi Colombia. Bagaimanapun, hanya orang tertentu sahaja yang memahami mesej tersembunyi itu dan mereka adalah 16 mangsa tahanan gerila FARC. Mereka telah menyebarkan mesej tersembunyi itu kepada tahanan lain (19 liberadossiguen ustedesanimo) yang bermaksud "19 people rescued, you're next, don't lose hope"

Untuk pertama kali dalam masa sedekah, tentera Colombia berjaya menyusup masuk (mesej tersembunyi melalui radio) ke kawasan gerila FARC, memberikan semangat dan harapan kepada tahanan.



Ini adalah salah satu teknik kreatif dalam penggunaan kod Morse demi menyelamatkan NYAWA tahanan dan cerita ini akan tertulis dalam SEJARAH penggunaan kod Morse untuk renungan generasi masa hadapan. Sebagai maklumat tambahan, lagu ni menang anugerah Cannes Lions 2011 untuk kategori Gold Best use of music and/or sound design


International Morse Code Lesson

Koleksi Majalah Radio Amatur Part 1

CQ magazine June 2001

CQ magazine March 2001

CQ magazine September 2001

CQ magazine Disember 2002

CQ magazine October 2003

CQ magazine April 2001

QST magazine April 1997

CQ magazine July 2003

CQ magazine January 2001

CQ magazine April 2002

CQ magazine June 2002

CQ magazine January 2003

CQ magazine March 2003

CQ magazine January 2002

CQ magazine May 2001

CQ magazine December 2002

CQ magazine May 2003

CQ magazine August 2002

CQ magazine May 2002

CQ magazine February 2001

CQ magazine February 2003

QST magazine December 1997

CQ magazine April 2003

CQ magazine November 2003

CQ magazine June 2003

CQ magazine July 2002

CQ magazine October 2002

Noise Di High Frequency


Pada awal pagi sabtu 20 Oktober 2012, sedang saya memanggil CQ di 14.011 MHz. Misao JH2XMK menjawab panggilan saya. RST adalah 449, signalnya lemah berbanding stesen lain. Setelah bertukar signal report, saya menamatkan QSO dan menghantar 73 kepadanya.

Stesen dari Jepun selalunya ramai ke udara di frekuensi seperti 10, 15 dan 20 meter band. Ini mungkin kerana antenna yang diperlukan tidaklah sebesar antenna biasa untuk 40 atau 80 meter band. Kebanyakan operator dari Jepun tinggal di rumah flat atau rumah bertingkat, ruang untuk memasang antenna amatlah terhad. Populasi di bandar-bandar utama negara Jepun juga lebih dari bandar utama di Malaysia.

Tempat tinggal yang terhad tidak mematahkan semangat mereka untuk ke udara. Sebaliknya menjadikan mereka bijak dalam faktor pemilihan antenna dan juga operating frequency. Jika dibandingkan dari aspek pembangunan teknologi, Jepun semestinya adalah negara yang dikatakan lebih maju berbanding negara lain. Penggunaan internet yang meluas, gadjet eletronik termaju dikatakan dihasilkan di negara Jepun.

Kehidupan penduduk Jepun di negara mereka yang pesat membangun sudah menjadi satu cabaran, terutama untuk operator radio amaturnya. Broadband over powerlines sebagai contoh, menjadi satu cabaran buat mereka. Noise yang terhasil sudah tentu menjadikan mereka susah untuk beroperasi dalam mode SSB. Kebanyakkan operator radio amatur Jepun memilih untuk beroperasi dalam morse code atau mode CW. Noise boleh ditapis dengan penggunaan IF atau AF DSP dan noise reduction. Receiving bandwidth boleh disempitkan dengan CW filter.

Urban area atau built up area menghasilkan banyak noise kepada frekuensi tinggi (HF), powerlines yang membawa voltan tinggi ke rumah atau premis, sambungan yang kurang sempurna pada tiang-tiang eletrik, insulator yang bocor, lampu neon, lampu LED, peralatan eletrik yang mengeluarkan spark dan sebagainya boleh meningkatkan kadar noise frekuensi tinggi.

Hasil dari pembacaan saya pada majalah QST, artikel bertajuk "powerlines interference" menceritakan tentang punca dan sebab gangguan berlaku, bagaimana untuk mengesan sumber gangguan dan juga bagaimana untuk menghapuskan gangguan terhadap frekuensi tinggi akibat dari powerlines.











Antara peralatan yang digunakan adalah, Line noise meter.




Friday, October 19, 2012

9M2PJU CW QSO WITH HA8QZ ON 10 METER BAND


Pada petang jumaat, 19 Oktober 2012 saya berjaya bekerja dengan Lali HA8QZ di 28 MHz. Signalnya kuat diterima di Rawang.


Signals Training Video TF11 - International Morse Code (complete)

Morse Code - Principles and Basic Techniques (US Army Signal)

SEJARAH TELEGRAPHY



Now simply called "CW", radio communication by Morse code was the only way to communicate for the first decade or more of Amateur Radio. Radiotelegraphy, the proper name, descends from landline (wired) telegraphy of the 19th century, and retains some of the old culture, including a rich set of abbreviations and procedures. Morse sent by spark gap transmitter was the first wireless communication mode. These "damped waves" were very broad and inefficient for communication. They were soon replaced by "Continuous Wave" (CW) transmission, using vacuum tube oscillators that were capable of a very pure note. Today, modern Amateur Radio transceivers use solid state components and microprocessors to support a variety of communication modes including CW, voice, image and many digital data modes.

Technique Of Hand Sending For CW Operator

Antara Straight Key, Iambic Key, Bug Dan Sidesweeper




Morse code sudah lama tertulis dalam sejarah, wujud sekitar 176 tahun yang lepas. Mode terawal dalam sejarah penggunaan elektrik sebagai penghantaran mesej melalui wayar dan juga radio tanpa wayar. Operator kod Morse telah banyak menyelamatkan nyawa mereka yang dalam kecemasan. Kapal Titanic sebagai contoh, operator radionya menghantar distress call atau panggilan kecemasan dalam kod Morse. Morse key atau CW key terdapat dalam beberapa jenis, di antaranya adalah:-


  1. Straight key - key yang biasa digunakan oleh operator radio tentera, kapal dan juga radio amatur. Key jenis ini sangat mudah, kerana hanya mempunyai 2 sambungan wayar. Bunyi dit atau dah ditentukan oleh ketukan operator. Ketukan pendek akan menjadikan bunyi dit dan ketukan yang panjang menjadikan bunyi dah.
  2. Iambic key - iambic key, eletronic key atau automatic keyer biasanya mempunyai 3 sambungan wayar dimana terdapat litar eletronic yang akan menentukan bunyi dit dan dah. Kelajuan ditentukan dalam word per minutes. Kelajuan dan nisbah dit dan dah boleh diubah pada litar eletronik yang mana selalunya terdapat dalam hampir kesemua transceiver moden. Sesuai untuk mereka yang sukakan kod morse dalam kelajuan yang tinggi (high speed telegraphy). Terdapat dalam versi dual paddle atau single lever. Begali menawarkan single lever iambic keyer yang boleh diubah kepada cootie atau sideswiper dengan hanya mengubah satu kedudukan suis.
  3. Bug - bug atau semi automatic adalah single lever key yang klasik selalu digunakan oleh operator radio. Mempunyai 2 sambungan wayar, tidak memerlukan litar eletronik sebaliknya key ini mempunyai mekanikal yang akan menentukan bunyi dit. Tetapi, untuk bunyi dah pula operator perlu menghantar secara manual.
  4. Cootie - Cootie atau sideswiper adalah satu single lever key, mempunyai 2 contact point dan 2 sambungan wayar. kiri dan kanan contact point adalah sama. Bunyi dit atau dah perlu ditentukan oleh operator.


Sila lihat video di bawah untuk melihat perbandingan di antara straight key, iambic key, bug dan juga cootie.

Straight key 


Dual Paddle Iambic Key


Single Lever Iambic Key


Bug atau Semi Automatic
 

  Cootie atau 
Sideswiper


Key jenis apakah yang menjadi pilihan anda?


Thursday, October 18, 2012

Panggilan Kecemasan Dari R.M.S Titanic

cerita yang dibikin semula menceritakan bagaimana kehidupan operator radio kapal RMS Titanic, Jack Phillips dan Harold Bride sebelum mereka mati. Walaupun mereka telah dibebaskan dari duty oleh kapten kapal ketika Titanic hampir karam, tapi mereka setia di radio room bersama CW keyernya, menghantar panggilan kecemasan, "CQD CQD SOS SOS CQD DE MGY MGY" sehingga ke hembusan terakhir. Inilah sejarah penggunaan kod Morse.



Tribute to the RMS Titanic Radio Operator



Tribute to the RMS Titanic, callsign MGY, with emphasis on the duty of her wireless officers.
They stayed with the ship, sending distress messages, even though released from duty by Captain Smith a few minutes before she went down.

When the water came onto the bridge, and the power failed, they were swept off Titanic and into the icy sea.

Senior operator John "Jack" Philips, just 25 years old died of hypothermia, and Harold Bride aged 21 years, second operator, was eventually pulled from the sea onto an overturned lifeboat.

Despite suffering crushed feet and frostbite, he insisted on being carried to the radio room of the rescue vessel Carpathia, where he remained assisting her operator who was exhausted from working continuous distress traffic and lack of sleep.



Over the next ninety years, radio and morse code were to save countless lives at sea.

My Personal Morse Code Story - Larry W2LJ


I was not always enamored with Morse Code like I am now.  This is a personal story that began when I was about 16 years old or so.  When I was in high school, I wanted to become a Ham.  I had the fortune of having an electronics teacher, Mr. Benson, who was already a licensed Ham.  We had a club station at school; and from demonstrations of the radios, I knew I wanted to get "in" on this great hobby.  Mr. Benson tried to teach a bunch of us the Morse Code; but I wasn't getting it.  In addition to the standard printed out sheet, I went to our local Lafayette Electronics store and purchased an Ameco Code Phonograph Album (remember those?).  No matter how much I practiced, it was no use.  It was all mumbo-jumbo; and unfortunately for me, I gave up after a relatively small amount of frustration.

Fast forward four years.  I had graduated college; had a full time, but not-so-great paying job; and had some free time on my hands, now that homework days were pretty much gone forever.  The local newspaper was advertising an Amateur Radio course that was to be given by a neighboring town's Adult Continuing Education Program.  The spark had reignited and was now a bonafide blaze.  I vowed to myself that this time I would actually do it.

Eight weeks later, as a result of hard work, study and perseverance, I had passed my Novice test.  The teacher had faked us out by promising to give us a "pre-test" so we would feel more comfortable taking the actual code test.  Little did we know that the "pre-test" would negate the need for us to take the "actual test".  We all passed with flying colors!  Approximately six weeks later, I received an envelope through the mail from the FCC with the much coveted "ticket".  I was a "gen-you-ine" Ham radio operator, licensed as KA2DOH.

Still with big dreams in my head, I worked towards my General license.  Visions of sitting behind a desk, with my legs on top, leaning back in a chair, all the while clutching the magic microphone working all the juiciest DX,  filled my brain.  Code was for Novices!  I was to leave it all behind !!!  The next few months saw my code speed rise to the magic 13 WPM mark.  My General Class license study guide was my constant companion.  Six months after receiving my Novice license, I took the test before an FCC examiner and was awarded my General!  I had done it - my hand was firmly grasping the Holy Grail !!  Look out DX, here I come !!!

I rushed home to my "new" used Kenwood Twins, the T599D and R599D.  These were my gift to myself for passing the General exam.  I fired the rig(s) up and got on 20 Meters (the Big Boys band, the promised land - Heaven!).  I took that ol' Astatic D-104 in hand and listened intently for a clear frequency and began to send my voice through the aether as I called CQ.  Meanwhile, unbeknownst to me, I was playing weird LSD style dream games with the TV downstairs.  The picture was a mess, the speaker sounded like a rabid and psycho Donald Duck was trapped inside.  Welcome to RFI, Mr. KA2DOH - welcome to stark reality.  This never happened in the six months of pounding the straight key !!!  The TV never so much as whimpered while I was pounding the brass.

The next few weeks were spent trying to overcome the RFI problem.  Various solutions were tried with varying success.  But it never went away entirely.  If I was to operate during "prime time" it was going to have to be Morse Code or be relegated to family imposed "quiet hours".  It soon became apparent to me that good old CW was to be my salvation.  And you know what ?  I came to love it !!  Once I stopped railing against it; I found that I enjoyed it immensely.  I came to love the sounds, the rhythms, the "song" that Morse Code is.  Today, I operate using CW 100 percent of the time.  In fact, right now I do not even own a rig that has SSB or AM capability.  If you want to find W2LJ, he'll be in the CW portion of the band, pounding brass and loving every second of it.

Learning the Code

Before I go into this .... if any of you out there want an "On-The-Air" tutor, I will do my utmost to get on the air with you for live CW practice, if you want!  Just drop me an e-mail and I'll try to meet you on the air, at a speed you're comfortable with - propagation permitting, of course!  Again, my e-mail is w2lj@arrl.net

There are probably as many different methods for learning Morse Code as there are students trying to learn it!  From the old Boy Scout method, where you would see the letters on a chart and then learn the characters to such "newer" methods as listening to letters delivered as jazzy, upbeat techno-tunes as in the popular CD, "The Rhythm of the Code".

We've come a long way from learning the Code from LP records (Ameco Code Course), cassette tapes, and even machines designed specifically for learning the Code, such as the old Instructograph.  Today there are a plethora of freeware, and shareware computer programs which will aid in your learning process.  Before we go into them, a few words first about learning the Code.

Learn each letter as a "sound".  Do not learn the letters at such a slow speed that you can count each dit and dah.  If you do it that way, then you will hit the dreaded "plateau"!  This is what we all faced in the olden days when we learned code the old fashioned way.  We learned code characters that were sent to us at a 5 WPM rate.  (For example, the letter C was learned as dah        di        dah        dit).  Then, as Novices, when we tried to increase our speed up to 13 WPM for the General license test; we found the going got rough at about 10 WPM.  It's at that point that Code is coming at you at a rate where you can no longer count the individual dits and dahs.  At this speed you have to unlearn everything you had learned to that point; and you had to learn the sound of each letter as a whole.  It's much easier if you learn it that way to begin with; and this is called the Farnsworth Method.  Play the letters as if they are being sent at a 10 -15 WPM rate (Example - learn C as dahdidahdit) ; but increase the spacing between each letter to achieve the effect of 5 WPM.  If you go this route you will not be tempted to pull your hair out later!

All that having been said, use the program you choose wisely.  This is not an endorsement of one program over another; but one of the nice things about the G4FON program is that you can click and choose the letters you want to concentrate on.  Once you have the basic letters, numerals and punctuation down; but find yourself having trouble with the "sound alikes"; you now have a remedy.  With the G4FON program, you can click just "H" and "5"; or "B" and "6"; or "L" and "F" or "L" and "R" or whatever you might be having a problem with.  (From my examples, you can see where I had problems. Hi!)  This way you can gain the confidence you need to go further.  Please remember that learning Morse Code is not a one shot deal! Once you've learned the 5 WPM rate to pass the license requirement, it doesn't end there.  Getting on the air, you will find that conversational CW begins somewhere around 13 to 15 WPM.  At slower speeds it's kind of like two people talking at each other instead of with each other.

Practice, practice and practice!  And then practise some more.  Listen to Code whether it's software generated or on the air from W1AW or from real time QSOs.  The more you listen, the better; but you want to limit your "concentrated" learning sessions to no longer than about 15 to 20 minutes.  After that you kind of go into "sensory overload" and it becomes counter productive.  A good thing to do is to set up one of the Code practise programs to generate a sound file that you can burn to a CD so you can listen in your car while driving; or even while doing other chores around the house.  It is amazing how much you can pick up when you're just in "listening mode" with the code playing in the background.

Another little "thing" that you can do to help yourself learn code is to "tongue" it.  I know, it sounds obscene; but all this is, is sounding out dits and dahs to yourself using your mouth.  While you're driving back and forth to work, code out some of the signs you see on the road.  Training yourself to translate normal words into Morse Code is good reinforcement. (Oh boy, it's a good thing I didn't miss that ditditdit dah dadadah didadahdit sign!)  You get the idea!

The most important thing - relax, relax and relax some more.  Frustration is your worst enemy and causes more people to give up than any other reason.  You will finally "get it", just don't put too much pressure on yourself!  Learning the Morse Code and using it is one of the most enjoyable aspects of this hobby as far as I'm concerned.  Don't make it out to be such an ordeal.  If you approach the whole process with a positive outlook; you will be amazed at what you can accomplish

http://w2lj.blogspot.com/p/morse-code.html

V85AN Demonstrate His Homebrew Iambic Keyer

CQ 14.030MHz With V85AN Homebrew Paddle

Just trying Azril V85AN homebrew keyer. He made it from a saw blade, equipped with magnetic base, so i can stick it the my cooking pan and it become large and huge base expansion. HIHI.

9M2SX QSO WITH 9M2NZ ON 7130 kHz

Two amateur radio operator from West Malaysia having their conversation on 40 meter amateur radio band. 9M2SX is from Penang Island and 9M2NZ from Nilai, Negeri Sembilan.

Lanun Di 145.500 MHz

Pirates on amateur radio 2m bands. Recorded by 9W2CEH from his QTH in Bangi, Selangor, West Malaysia.

Indoor antenna operating tips


For the past few years I have been tinkering with many forms of indoor amateur radio antennas. I want to pass along these operating tips to try helping other operators in my position.
These are mainly observations on what has worked and what hasn't. Just because you can't have a full-blown station doesn't mean you can't be active on the HF bands.


Your choice of modes means a lot!

One of the biggest factors that affects your success using an indoor antenna on the HF bands is your choice of mode. While these tips are only suggestions, they have proven to be successful for me and have enhanced my stations performance.


CW Rules!

CW means more DX!
Let's face it, for any sort of weak signal work, CW is the most efficient mode available to us today! Big DX'peditions usually concentrate most of their effort in CW for that reason.
With all of the varied modes available for HF operation available, CW has always been my best mode for success. I have been a ham for almost 30 years now and have always preferred CW. New hams aren't required to learn it to get their licenses but there are some factors that make it the perfect mode to use when working with limited antennas. Remember, Morse Code is a 100% duty cycle mode so your signal will stand a better chance of being heard than if you were using phone.
This fact became apparent to me many years ago when I used to do satellite operation. Back when I had outdoor antennas I became interested in operating satellites. There were many available like the RS-10, RS-12, and RS-15 that could be worked with basic HF/VHF equipment. They were low orbiting birds so passes came and passed in as little as 4 minutes. I always found it quite difficult to find and tune in a station using phone so switching to CW usually netted me more contacts per pass. Ever since then I would say that about 95% of my HF activities have been with CW.
Now with indoor antennas I find that CW allows me to hear and work signals that are weaker due to the reduced performance. There have been many DX'peditions where they operate on all bands and all modes. I can usually hear them on CW but find it hard to pick their signal out when operating phone on the same band.


Digital Modes

RFI and digital modes
In my situation I have problems with PSK31 and RFI. Many times my PC will lock-up, programs will start themselves, and strange things can happen during transmission.
Thanks to modern technology and computer integration into the hobby, the digital modes have really helped when limited with indoor antennas. PSK31 is one mode where the error correction capabilities have really helped out. Plus, most PSK31 operation is at greatly reduced power which means you can run slightly higher than recommended power so that you can be heard. I have run PSK31 at about 30 watts and made many contacts without getting any reports of bad IMD.
RTTY is another mode of choice and FSK is recommended over AFSK. AFSK RTTY really uses SSB to transmit tones and I have found that any "Phone" mode generates more RFI both at the operating position and possibly with neighbors.
If you plan on operating using digital modes, how you cable your equipment is can make a big difference.
Always try routing RF cables away from computer cables. At my operating position, all RF cables come in above desktop height and go up. My PC and all of it's cabling is below desktop height.
Adding toroids around your keyboard and mouse cables to stop RFI at the PC.
Try using a different keyboard if you find RFI getting in. I had a no name type keyboard that went nuts when ever I transmitted. I switched that to a better keyboard (name brand) and eliminated the problem.

Phone (SSB)

I don't use phone much
I would say that the total number of phone contacts is only about 10%. I generally use it on 75 meters to check into a local net. The ROC City net is a local net, Wednesdays at 8:00 pm on 3.825MHz.
Many people give up when trying to use an indoor antenna because they use phone. Remember, phone isn't a full duty cycle mode. Your power is directly related to the amplitude of your voice and ALC settings of the radio.
Another issue with phone is that there is a greater chance of creating RFI that could affect both your equipment and your neighbors televisions, stereos, phones, and computer speakers.
Not being a big fan of phone operation I can only suggest that you do what ever works for you. Don't give up just because one thing doesn't work. Band conditions are constantly changing so choose the band that has the best propagation for that moment.
Pick stations that have strong signals. If I hear a station that's at least 3db above the noise floor I can usually log a good contact. If it's a DX'pedition, I generally wait till the end after some of the "feeding frenzy" has cleared out.
 



Wednesday, October 17, 2012

RF average, pulse and peak envelope power measurements


- a summary or overview of the different types power level measurements that can be made - average power, pulse power, peak envelope power, PEP.

RF and microwave power meter tutorial includes:
    •  RF / microwave power meter basics
    •  Average, pulse & PEP
    •  Sensor types
    •  RF power measurements


When measuring RF and microwave power levels it is necessary to understand the nature of the signal as this can have an impact on the power measurement and the instrument used.
Terms including: average power, RF pulse power, RF peak power and peak envelope power, PEP require different measurement techniques and as a result they need different sensor types to measure them.

RF average power

The most obvious way to measure power is to look at the average power. This is defined as the energy transfer rate average over many periods of the RF waveform.
The simplest waveform to measure is a continuous wave (CW). As the signal is a single frequency steady state waveform, the average power is obvious.
For other waveforms the averaging parameters may be of greater importance. Take the example of an amplitude modulated waveform. This varies in amplitude over many RF cycles, and the RF power must be averaged over many periods of the modulating waveform to achieve a meaningful result.
To achieve the required results, the averaging period for RF power meters may range from several hundredths of a second up to several seconds. In this way the RF or microwave power meter is able to cater for the majority of waveforms encountered.

RF pulse power or peak power

In a number of applications, it is necessary to measure the power of a pulse of energy. If this were averaged over a long period of time, it would not represent the power of the pulse. In order to measure the power of the pulse itself, a method of defined exactly what must be measured.
As the name pulse power implies, the power of the actual pulse itself is measured. For this the pulse width is considered to be the point from which the pulse rises above 50% of its amplitude to the point where it falls below 50% of its amplitude.
As the pulse is likely to include some overshoot and ringing, the most accurate term for the power is the pulse power. Peak power would imply that the value of any overshoot would need to be taken, whereas the actual power measurement required is that of the overall pulse.

Peak envelope power, PEP

For some applications another form of RF power measurement is required. Called peak envelope power, PEP, it is used to measure the power of some varying waveforms.
There are many instances where a power measurement that takes the peak of the envelope is needed. Many digitally modulated waveforms may require this, and also transmissions such as AM and Single Sideband may also need this type of RF power measurement.
The envelope power is measured by making the averaging time greater than the period of the modulating waveform, i.e. 1/fm where fm is the maximum frequency component of the modulation waveform.
This means that the averaging time of the RF power measurement must fall within a window:
It must be large when compared to the period of the highest modulation frequency.
It must be small compared to the period of the carrier waveform
The peak envelope power is therefore the peak value obtained using this method.

Summary

Of all the forms of RF power measurement, the average power is the most widely used. It is the most convenient to make, and often expressed the value that needs to be known. However pulse power, sometimes referred to as peak power, and also the peak envelope power also need to be known on many occasions. However the techniques and equipment needed to make peak envelope power and pulse power are different to those needed for average power. Accordingly it is necessary to understand the differences between the different types of RF power measurement and the equipment needed.

RF average, pulse and peak envelope power measurements


- a summary or overview of the different types power level measurements that can be made - average power, pulse power, peak envelope power, PEP.

RF and microwave power meter tutorial includes:
    •  RF / microwave power meter basics
    •  Average, pulse & PEP
    •  Sensor types
    •  RF power measurements


When measuring RF and microwave power levels it is necessary to understand the nature of the signal as this can have an impact on the power measurement and the instrument used.
Terms including: average power, RF pulse power, RF peak power and peak envelope power, PEP require different measurement techniques and as a result they need different sensor types to measure them.

RF average power

The most obvious way to measure power is to look at the average power. This is defined as the energy transfer rate average over many periods of the RF waveform.
The simplest waveform to measure is a continuous wave (CW). As the signal is a single frequency steady state waveform, the average power is obvious.
For other waveforms the averaging parameters may be of greater importance. Take the example of an amplitude modulated waveform. This varies in amplitude over many RF cycles, and the RF power must be averaged over many periods of the modulating waveform to achieve a meaningful result.
To achieve the required results, the averaging period for RF power meters may range from several hundredths of a second up to several seconds. In this way the RF or microwave power meter is able to cater for the majority of waveforms encountered.

RF pulse power or peak power

In a number of applications, it is necessary to measure the power of a pulse of energy. If this were averaged over a long period of time, it would not represent the power of the pulse. In order to measure the power of the pulse itself, a method of defined exactly what must be measured.
As the name pulse power implies, the power of the actual pulse itself is measured. For this the pulse width is considered to be the point from which the pulse rises above 50% of its amplitude to the point where it falls below 50% of its amplitude.
As the pulse is likely to include some overshoot and ringing, the most accurate term for the power is the pulse power. Peak power would imply that the value of any overshoot would need to be taken, whereas the actual power measurement required is that of the overall pulse.

Peak envelope power, PEP
For some applications another form of RF power measurement is required. Called peak envelope power, PEP, it is used to measure the power of some varying waveforms.
There are many instances where a power measurement that takes the peak of the envelope is needed. Many digitally modulated waveforms may require this, and also transmissions such as AM and Single Sideband may also need this type of RF power measurement.
The envelope power is measured by making the averaging time greater than the period of the modulating waveform, i.e. 1/fm where fm is the maximum frequency component of the modulation waveform.
This means that the averaging time of the RF power measurement must fall within a window:
It must be large when compared to the period of the highest modulation frequency.
It must be small compared to the period of the carrier waveform
The peak envelope power is therefore the peak value obtained using this method.

Summary

Of all the forms of RF power measurement, the average power is the most widely used. It is the most convenient to make, and often expressed the value that needs to be known. However pulse power, sometimes referred to as peak power, and also the peak envelope power also need to be known on many occasions. However the techniques and equipment needed to make peak envelope power and pulse power are different to those needed for average power. Accordingly it is necessary to understand the differences between the different types of RF power measurement and the equipment needed.

Removing RFI from Microphone Inputs


Many amateur radio stations today are experiencing terrific RFI (Radio Frequency Interference) that is impeding their audio signals and causing very garbled and distorted audio. Careful listening indicates that MANY SSB signals on the air today exhibit RFI - sometimes not enough for the other stations to notice (because they are listening on a 3" speaker in their transceiver), but careful listening in a wideband receiver with VERY high quality receiving equalizers and studio monitor speakers allows this slight interference to become VERY annoying. And, of course, there are also signals on the bands that have terrible problems with RF getting into their audio lines, causing all sorts of problems.

1. Shielding of the Mic Connector


We, here in the Heil Sound lab, have discovered a very interesting fact. Most of the major transceivers today do NOT ground their microphone shields! That's correct - the mic connector shields FLOAT! Now wasn't this one of the FIRST things we learned about building RF transmitters with speech audio sections? GROUND those shields!! So, we came up with a very simple fix that just about anyone can make to their rig. You don't have to get inside the radio, so you don't void any warranties. The fix is simple and effective.
This applies to the 4 and 8 pin Foster (that's the Japanese company that builds those dang little mic connectors!!) microphone connectors so common on today's rigs.
First, unplug your Heil (what - you don't have one yet??) microphone cable from the front panel of the transceiver. Do this first, because you don't want the mic plug connected to the sensitive circuitry inside the radio while you're soldering.
Remove the two small #4 Phillips head screws and the cable clamp they hold. Then remove the tiny Phillips head screw that holds the rest of the metal sleeve. Slide that back onto the mic cable. Now, cut off the end of a resistor, or get a piece of #20 solid, tinned wire about 3" long. Locate the mic pin that has the shield of the mic cable soldered to it.
With a small iron, carefully solder this solid wire to that shield and pin. Bring the sleeve back up the cable and attach to the connector with the small screw. This leaves the solid wire coming out the back of the connector. Replace the cable clamp, and (as you do that), tightly wrap that solid wire around one of the #4 Phillips head screws and tighten the clamp assembly very well.
What you have accomplished is grounded the shield to the transceivers chassis ground through the ring on the mic connector. (Make sure that ring is tight). This has been a big help to many stations with RFI problems and should help you clean up your signal.

2. Eliminating Common-Mode Current from Shields

Common-mode current can be a serious problem in amateur radio stations. This current, which can start flowing due to mutual coupling between an antenna and your coax, frequency-sensitive problems in your station ground, or a floating ground in your rig's power supply, can create any number of headaches, including RFI on your microphone line. In a nutshell, "ground" can "rise above ground" on some frequencies.
Several remedies are available.
A simple one is to wind a coil in your coaxial cable, about 8 or 10 turns of about 6" diameter, as close to the rig as possible. Hold the turns in place with black tape. This forms an RF choke like the one often used at the feedpoint of a dipole, Yagi, or Quad, and for the same reason. This choke can break up the current flow, and may have miraculous results (both in terms of effectiveness and simplicity!).
Another tactic is to slip snap-on ferrite cores onto the microphone line. On an AD-1 boomset adapter cable, snap one core onto the PTT line, another onto the microphone line, and another over the combined cable. If you are hearing RFI in your headphones, slip one or more cores onto the headphone line.
Earlier, it was mentioned that your rig's power supply might be involved. Many power supplies, especially switching-mode types, use a floating ground. A number of Astron® power supplies, which are very popular because of their low cost and excellent performance, use a floating ground. This can cause an amateur transceiver to take off scanning when you transmit, or set up common-mode current. The solution is to connect a short strap from the power supply's Black (negative) output terminal to the chassis of the power supply (often there is a convenient ground lug inside the cabinet). Then, connect 0.01 µF and 0.001 µF 50-Volt disc ceramic capacitors from the red ( + ) to the black ( - ) output terminals; the capacitors will shunt any RF on the DC line to ground, which now really is ground. Please use caution when doing any work inside your power supply, and utilize the services of a qualified electrician if you have any doubts about your capabilities. Heil Sound, Ltd. specifically disclaims any responsibility for personal injury or damage to equipment caused by improper modification work on station components.