Am I Going to get TR-696M Citizen Band CB Radio?
Ham Radio, Hobbies January 30th, 2008
Since childhood, I’ve been dreaming to operate a CB radio just like what has been portrayed by TV in that era. Budget restriction and equipment availability however restricts me from getting involved in the radio communication hobby at that time.
Now few years later, I might just had the chance to get myself a type-approved (to be used in Malaysia) Texas Ranger (TR-696M) CB radio for home use.
Citizen Band (or Jalur Rakyat) does not require license in Malaysia so long as you use a type approved rig like TR-696M. The rig operates on 11 meter CB radio band and it can access frequency range from 26.965 Mhz to 27.555 MHz, divided in 40 channels.
The normal modulation for this type of radio is SSB (optinally FM), which makes it an attractive choice for DXing (international long distance communication).
However currently propagation for 10-11 meter band is not as good as few years ago, which means that I might not get as many contact as I would like to get using this radio. This, along with the cost of erecting an effective 11 meter antenna makes me think twice before obtaining this Citizen Band Base Station Rig.
So am i going to get Citizen Band Radio? An interesting dillema.. any thoughts?
Where to get CB Radio in Malaysia
Although MCMC mandated that we should use a type-approved CB radio set, surprisingly there are only one type of CB radio rig which is type-approved, that is Texas Ranger TRM-696. You currently you can get new set from 9M2DA, Deen Attan from CBMalaysia website.
OWA 4 Element Yagi for 2 Meter – Great F/B ratio
Ham Radio, Hobbies January 28th, 2008
I would like to share with you a compact 4 Element Yagi-Uda antenna design for 2 meter amateur radio band. This antenna has great front-to-back ratio and is optimized for wide range of frequency, a bargain for its compact design (about 76 centimeter long).
Although this antenna has almost the same gain as any simple 3 element yagi antenna (7-8dBi), this design has a significantly improved Front-to-Back ratio which is great for blanking noises and foxhunting purposes
Here how the antenna would look like
Front-Back Ratio Gain
VSWR from 143.000 MHz to 148.000 MHz
Antenna dimensions
Element, Length, Space from Reflector (all in cm unit)
- Reflector – 103.0, 0.00
- Driver – 95.0, 26.0
- Director 1 – 92.0, 39.0
- Director 2 – 83.0, 76.0
Calculated Center of Gravity – 35.0 cm
This antenna has been modelled using YagiMAX 3.0 software by K4VX
Please leave comments if you have sucessfully built this antenna. I would like to hear your experiences.
Tags: 2 meter, amateur radio, antenna, hamradio, Hobbies, hobby, vhf, yagi, yagi-uda
Cover version of Hujan – Bila Aku Tiada
Music January 23rd, 2008
2 Meter Amateur Radio Slim Jim Project
Ham Radio, Hobbies December 29th, 2007
Hi there, sorry for being quiet for a while, but rest assured I was on some knowledge discovery mission to learn about building Slim Jim antenna for two way radio communication (specifically for Amateur radio band).
This antenna is specifically built to resonates within 2 meter amateur radio band (144-148MHz). This antenna has been build with the help of my friend, Amet who is a trained electrician.
Slim Jim Plan that we use
Please refer to 2 Meter Amateur Radio Slim Jim Plan post for more information
Among the items used to construct the antenna are :
- Aluminium tube 8mm diameter, sold in 10 feet (can be obtained from hardware store, 10feet, RM10)
- U PVC Pipe (15mm-20mm) for holding with T junction, RM4
- SO-239 connector (for mobile rig), RM10
- Coax Cable (either RG-8 RM7/m or RG-58 RM2/m, quality varies
Tools that we used are (included with cost if you want to buy them):
- Bosch hand drill for drilling pipes and aluminium tube ( RM100)
- Rivet / Riveter for attaching coax cable to antenna (RM 20)
- Bender (RM 30)
- some wire cutter
- Hack saw for cutting pipes and aluminum (RM 3)
- and oh yes, we *dont use* any torch welder for this one
As you already might guess, the cost for constructing the antenna alone cost slightly less than RM30 (~USD 10, except cable and tool cost), the Slim Jim is mounted on the roof of my house with ordinary TV antenna bracket, with the height of close to 40 feet from the ground.
Why build your own antenna? It is a way for me to better understand about radio wave resonance and to learn more about how to build a radio antenna to tune in to specific frequency, something that commercial antenna lacks, because it is built to tune to a wider range of frequency due to market demand.
This antenna is said to have a gain of 3.2dBi, though I don’t have confirmation about this information.
SWR Reading
Here’s the reading I’ve obtained from Diamond SX-200 SWR meter, using 20 watt output power :
- 144 Mhz – 1.2
- 146 Mhz – 1.3
- 148 Mhz – 1.5
The reading is kinda bit off from the center of frequency :p, I know. this is due to my poor handling with aluminium bender. I’ve made it almost an inch longer, so that kinda explains the SWR reading is kinda centered on the lower frequency.
However this is way cheaper than buying a commercial antenna which cost me a lot of bucks, and I surely have more fun!
What can be improved?
Supposed if you want the antenna to resonate better, you could replace aluminum tubing with copper or brass tube and replace RG-58 coax cable with a low loss cable such as RG-213 or RG-8 which was used in this experiment.
What’s next ?
Next I’ll try to construct a ribbon antenna (?), which is a a very flexible antenna to be used with a portable handy radio, when you are traveling and gives you about 3dBi gain when positioned carefully.
cheers
Tags: amateur radio, antenna, hamradio, Hobbies, hobby, slimjim
About
