Simple 10 meter loop antenna

Here’s a diagram for a simple 10m loop antenna. Although 10 meter band is not very good at this time of the year, the operating condition is predicted to be improving in the next couple of years.

Simple Antenna for 10 meter operation

10meter loop antenna

A/B Value for 28.2 MHz
A = 73″
B = 146″

A/B Value for 28.5 MHz
A = 72″
B = 145 3/4″

A/B Value for 27.5555 MHz (freebander)
A = 73 1/2″
B = 150 3/4″

Data from MMANA-GAL software

10 meter loop data for 28.5MHz

The antenna can be build from Copper wire or aluminum tube.
Here’s the MMANA-GAL file for reference : 10meterloop_simple.maa

Amateur Radio: Malaysian APRS Seminar in Unimap (Perlis)

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
PA0HMW,F0DKS,VK3PAT,VK3BFM,VK6MX,VK3EO,
P29EO,VK6MX,VK4GO,VK4GO/BD,JA1OGS
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)

Synopsis:
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.

Info Direction QRV: 9M2RMK 147.9800Mhz Shift -0.600 Tone 203.5
Info Direction on :
a) Wikimapia
b) Google Maps

Those interested to learn more about APRS technology are invited to join in the seminar. It’s free of charge!

RAE 2008-2 Results : Congrats to new Malaysian Ham!

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 :

For those who didn’t pass, dont despair.. there’s plenty of time to study for the next RAE!

MCMC has updated Malaysian Amateur Radio callsign database

MCMC (Malaysian Communication and Multimedia Comittee) has updated Malaysian Amateur Radio Apparatus Assignment and Callsign database, which can be viewed here – http://www.skmm.gov.my. The updated database include details of newly registered hams who’ve recently passed RAE 2008-1 examination in April.

Alternatively you could try the experimental AJAX web interface from ashamradio callsign project. Thanks to 9M2CIO for making the database available to use freely.

A very quiet September for 10 meter band

Woops, seems like the SSN (smoothed sunspot number) count for this month is equals to 0.

I only manage to make 6 contacts with DX station on 10 meter during September. Partly due to bad propagation, partly due to my busy schedule, which kinda limit my ham activities to Sundays and Saturdays.

I’ve been getting all sorts of questions about working 10 meter from fellow hams in my place. I advises them against it as the propagation right now isnt as great as couple months before

Plus, I’ve known quite few local hams that regret that they venture into 10 meter unprepared, as it requires a lot of patience and different skills to work with.

In another note, I would like to extend my warmest congratulations to those who has passed the 2008 Morse Code test, more details in 9M2MGL website

My Homebrew 10 Meter Moxon antenna in my backyard

I took some time off to build my first HF antenna using the plan I’ve obtained few months ago. I chose moxon as my first 10 meter HF antenna as it is small and compact and it is directional, allowing me to focus it into a single direction for a pretty quiet QSO, without much interference.

The material I used in building this moxon are :

  • Green ground (12 Gauge ?) wire, it has 7 copper wire inside it.
  • PVC pipe (3/4″ diameter) as necessary to hold the wire in place, you can use other materials too, as long as it formed the basic dimension of moxon antenna

Antenna Plan and Results
I use the plan described in this post; 10 Meter Band Compact Directonal Antenna and started building it immediately. The result of the antenna can be seen here :

9w2wtf moxon

9w2wtf moxon

Performance
Although I build it only as a temporary antenna (thus its flimsy), it performed rather well when compared to other types of popular 10 meter band antenna in my place (Delta Loop, Inverted-V) as the antenna is directional and it does not requires the use of transformer balun.

I’ve managed to make contact with 12 stations in 6 days since it has been erected.

Some tips working on 10 meter band

  • Use a good low loss cable such as RG-8 or Belden 9913
  • Make sure you know where you point your antenna, the direction of your antenna is crucial if you ever to make contact with distant station.
  • The propagation is pretty good during daytime between 3pm – 8pm by my observation, use that time window wisely.
  • Use directional antenna like Moxon or Yagi as they allow you to focus your transmission to a certain direction and eliminate excessive interference on the band.
  • Be patient

That’s it and good luck!

p/s:
I wouldn’t recommend PVC pipes if you are planning to erect a permanent antenna as they are flimsy. Use aluminium pipes or copper tubes as they are more durable and offers best performance.

10 Meter band ham radio calling frequency in Malaysia

Since 10 meter activities gained popularity lately in Malaysia, I decided to publish 10 meter calling frequency for the benefits of local hams in my region :

28.480 MHz USB
28.485 MHz USB
28.490 MHz USB
28.495 MHz USB
28.500 MHZ USB

Most local and DX activities concentrated on these frequencies with 28.490 MHz being the most popular for calling DX stations.

Tips for newbies hams on HF
Be sure to ask if the intended frequency is unoccupied by asking (“is this frequency in use ?”) at least three times. Then proceed to make a general call, “CQ CQ CQ this is 9W2QSO 9W2QSO 9W2QSO calling CQ CQ CQ, this is 9W2QSO calling any station and standing by” and listen for any call for few moments.

In Malaysia, the best time for 10 meter USB operation is around 4:20pm – 10pm, your milleage may vary though.

Good luck.

The Homebrew Slim Jim Antenna Gain

I’ve been searching for information regarding the radiation angle and the gain of slim jim antenna, but found none of it. So I decided to build the model of the antenna inside the ever useful MMANA-GAL software to get the information I needed myself.

From what I can surmise, the slim jim has a slightly lower radiation angle than vertical dipole antenna and is easier to mount, thus it is suitable to use for point-to-point communication VHF-UHF operation. It has a gain of about 2.8dBi-3.2dBi in free space and 4.8-5.8dBi when mounted at about 30feet from the ground. Here’s the result of MMANA-GAL :

Slim Jim 9w2wtf

Slim Jim mounted 30 feet above ground
Slim Jim Antenna gain

Slim Jim in free space

CWIRc : Send Morse Code in IRC – tools for Amateur Radio Operator

Eager to practice your CW skills but you have nobody to practice with? In some countries like Malaysia, CW knowledge and proficiency is still required to operated HF portion (except 10 meter) of the Amateur Radio band.

Having said that, I’d like to present CWirc, an XChat irc client plugin which enables you to send and receive morse code through IRC. Developed by a fellow ham F8EJF, CWIrc has a lot of features which really enhance your CW experience on the internet, including the option of hooking up a real CW keyer using serial port interface.

CWIrc enables you to exchange morse code with fellow irc users on the internet, provided that the other users also knows morse code and has installed CWIrc. Though this might sound a little bit of a stretch when thinking the odds of meeting people with both requirements, it is actually not so in reality. You can find those kind of people exactly in #cwirc on irc.freenode.net server who are eager to chat with you in CW.

Screenshot

Requirements

  • Linux (or Unix based) machines (I personally used Ubuntu)
  • XChat IRC Client
  • CWIRc plugin

Both XChat and CWIrc are included in Ubuntu (as well as Debian) software repository, so you don’t need to compile or download separate package from their respective websites.