Computers, Ham Radio, Radio, Technology October 17th, 2010
MYCallsign – the Malaysian Amateur Radio Callsign Query Mobile Application has been updated, now it comes with a new spiffy logo. The mobile application can be installed on most Nokia, Sony-Ericsson, Motorola and Samsung phones. The application can be used to display information regarding an amateur radio callsign, such as handle (fullname), apparatus assignment (AA) and AA expiry date, and it is handy for recording QSO information in the logbook.
The application is licensed under the GNU General Public License 2.0 and is available for download at MYCallsign GoogleCode website
The new MYCallsign logo was created by Piju (9W2PJU – http://9w2pju.hamradio.my)
diy, electronics, Radio, Videos September 15th, 2010
Foxhole radio receiver or Crystal receiver is a form of radio that does not operate on local oscillator, which makes it hard to be detected by other electronic device. One of the most interesting thing of Foxhole radio is that it could be operated without the use of batteries, as it is powered solely by the radio waves through its long wire antenna.
Foxhole radio was (supposedly) popular during World War II because it enabled the GI to receive radio broadcast in the middle of the war, particularly in France as the Germans has outlawed the use of radio by civilians, thus the American GI need to build their own receiver to receive broadcasts. Typical component of foxhole radio during those days are : a period razor blade (not the newer galvanized one), carbon (obtained from pencil) and some copper wire with woodblock or cardboard as its base.
I’ve found a video on Youtube on how to build a Foxhole receiver, it still requires considerable skills and experience to build a working version of the receiver though.
Take a look at this video shot on 3rd September 2010, where we can see that 9W2DI has managed to get contact from Macau, China on (28.495 MHz) 10 meter band! Apparently the 10 meter band is not dead like most people used to say. 9W2DI (Pak Din) is QRP hamradio enthusiast, you can see all his QRP video from his YouTube channel
Visit his blog for more information about his activities : http://9w2di.blogspot.com
Here is a plan for homebrewing a 2 Meter Square Dipole plan. The advantage of this antenna is that it is unidirectional, and it takes less space than the regular 2 meter dipole. The calculation included on the diagram below is for building the antenna using copper tubing, you should use MMANA-GAL or other antenna simulation software to come up with new dimension for other materials (aluminium, wire, etc).
Click on the diagram to enlarge it. Hopefully this will help you in brewing new antennas! Original plan taken from KOFF website
My friend, 9W2AZV gave me the drawing for this 2 meter antenna, I haven’t tried building it yet. The antenna seems to share common design with a collinear antenna. I ran this schematic in MMANA-GAL and found out the antenna has a very nice flat radiation pattern which maximize the transmission reach.
Here’s the the antenna design:
Tak-Tenna is a type of compact antenna which is suitable for those who has space constraints on erecting their HF antenna. It is small enough that a 40 meter Tak-Tenna is just about the size of a 4-element Yagi 2 meter antenna. Here’s photographs of 40-meter Tak-Tenna in action. Compare that to the typical 40-meter dipole or Inverted-V configuration ! Thus it has the advantage of space-saving and unobtrusive setup when compared to other design of HF-antenna.
Tak-Tenna is available in 3 models – 40, 20, and 10 meters, with the 40 meter model can be use on 40, 30, 20, 15, and 10 meters with a tuner.
Refer to this article: “The TAK-Tenna™ Review – A Limited Space HF Antenna Review” for further review on Tak-Tenna performance and advantages.
Tak-Tenna can be ordered from the official Tak-Tenna website
Here’s a 12 Element UHF Yagi antenna that I designed for my friend, 9w2azv. He’s going to use that antenna for his client, that needs to hit a repeater 10 kilometers away from their location.
Here’s are the measurement for the antenna :
Polar Plot for the Antenna (E-Plane)
Polar Plot for the Antenna (H-Plane) at 2 Wavelength height
Announcement, General, Ham Radio March 2nd, 2009
A seminar on APRS will be held in Universiti Malaysia Perlis (UniMAP) on 7 March 2009. Details of the talk as follows:
Name: Art Takahashi
Academic Qualification: Satellite Microwave System Engineer
Expert Field: Satellite communication engineer & Hamradio
Experiences: Hamradio licence holder about 40 years
Holder Radio Callsigns
Working for NEC Japan Yokohama & Australia Papua New-Guinia
Professional Bodies Membership:
Rens & Rens , Stedehouwer NERG
The Netherland , Australia Japan
Title: A.P.R.S (Automatic Position Report System)
Explain what is all about APRS, how it works and what do with it.
Main reason about my second visit is to Malaysia is to help radio amateurs in this country, to understand a other side of hobby. So they start building digital electronics project for the radio amateur hobby. (APRS)
Date: 7 march 2009
Time: 10:30 am ~ 1:30 pm the length from the seminar is depends about visitors interest.
Vanue: Lecture Hall, UniMAP Kuala Perlis.
Those interested to learn more about APRS technology are invited to join in the seminar. It’s free of charge!
Current Issues, Ham Radio February 7th, 2009
Radio Amateur Examination (RAE) results is out! Congratulations to those who have passed the examination! Heck even piju passed the test!
You can view the results here : RAE 2008-2 results from MCMC website.
Important Forms to download :
- Letter Of Reference (to be signed by two 9M license holder)
- Declaration of Secrecy
- Application for Apparatus Assignment
- Callsign Application Form
For those who didn’t pass, dont despair.. there’s plenty of time to study for the next RAE!