Wednesday, October 19, 2005

Desktop Power Supply from a PC modified for Rig

Here is a homebrew P.C. power supply modified for Rig usage but current is only limited to about 7 Amps. So if you want to power your VHF Amateur Radio at high power it will not take it!

Example on a ICOM IC-2100H at High Power will be 55Watts and it will consume 12Amps! This is too high current drain therefore the modified power supply will definately burn out in about 60 Minutes usage. But if you use Medium Power which is 10Watts. Then the modified power supply will be suitable for the usage. Just add a Amp meter in series with the Rig and powersupply to monitor the current drain will not get your powersupply burned out!


Happy Homebrewing

Monday, October 10, 2005

Do you know Series - 9

1. What is a coaxial cable?

A. Two wires side-by-side in a plastic ribbon
B. Two wires side-by-side held apart by insulating rods
C. Two wires twisted around each other in a spiral
D. A center wire inside an insulating material covered by a
metal sleeve or shield

2. A mobile radio may be operated at home with the
addition of which piece of equipment?

A. An alternator
B. A power supply
C. A linear amplifier
D. A rhombic antenna

3. What may cause a buzzing or hum in the signal of an
HF transmitter?

A. Using an antenna that is the wrong length
B. Energy from another transmitter
C. Bad design of the transmitter's RF power output circuit
D. A bad filter capacitor in the transmitter's power supply

4. What is the amateur station activity known as fox hunting?

A. Attempting to locate a hidden transmitter by using receivers
and direction-finding techniques
B. Attempting to locate a hidden receiver by using receivers
and direction-finding techniques
C. Assisting government agents with tracking transmitter
collars worn by foxes
D. Assembling stations using generators and portable antennas
to test emergency communications skills

5. If you answer someone on the air and then complete your
communication without giving your call sign, what type of
communication have you just conducted?

A. Test transmission
B. Tactical signal
C. Packet communication
D. Unidentified communication

6. How many watts of electrical power are used by a 12-VDC
light bulb that draws 0.2 amperes?

A. 60 watts
B. 24 watts
C. 6 watts
D. 2.4 watts

7. What are the receiving and retransmitting frequency
bands used for Mode V/U in amateur satellite operations?

A. Satellite receiving on 435 to 438 MHz and
retransmitting on 144 to 148 MHz
B. Satellite receiving on 144 to 148 MHz and
retransmitting on Amateur bands in the range of 21 to 30 MHz
C. Satellite receiving on 144 to 148 MHz and retransmitting
on 435 to 438 MHz
D. Satellite receiving on 435 to 438 MHz and transmitting
on 21 to 30 MHz

8. How fast does a radio wave travel through space (in a vacuum)?

A. At the speed of light
B. At the speed of sound
C. Its speed is inversely proportional to its wavelength
D. Its speed increases as the frequency increases

9. What must you transmit to identify your amateur station?

A. Your "handle"
B. Your call sign
C. Your first name and your location
D. Your full name

10. Which of the following one-way communications may
NOT be transmitted in the amateur service?

A. Telecommand to model craft
B. Broadcasts intended for reception by the general public
C. Brief transmissions to make adjustments to the station
D. Morse code practice

11. What do RTTY, Morse code, AMTOR and packet
communications have in common?

A. They are multipath communications
B. They are digital communications
C. They are analog communications
D. They are only for emergency communications

12. Depending on the wavelength of the signal,
the energy density of the RF field, and other factors,
in what way can RF energy affect body tissue?

A. It heats body tissue
B. It causes radiation poisoning
C. It causes the blood count to reach a dangerously low level
D. It cools body tissue

13. What is the correct way to call CQ when using voice?

A. Say "CQ" once, followed by "this is," followed by your call
sign spoken three times
B. Say "CQ" at least five times, followed by "this is,"
followed by your call sign spoken once
C. Say "CQ" three times, followed by "this is," followed by
your call sign spoken three times
D. Say "CQ" at least ten times, followed by "this is,"
followed by your call sign spoken once

14. Where should you connect the chassis of each piece
of your station equipment to best protect against
electrical shock?

A. To insulated shock mounts
B. To the antenna
C. To a good ground connection
D. To a circuit breaker

15. What instrument is used to measure standing wave ratio?

A. An ohmmeter
B. An ammeter
C. An SWR meter
D. A current bridge

16. If signals from your transmitter are causing front-end
overload in your neighbor's television receiver, who is
responsible for taking care of the interference?

A. You alone are responsible, since your transmitter is
causing the problem
B. Both you and the owner of the television receiver
share the responsibility
C. The FCC must decide if you or the owner of the
television receiver are responsible
D. The owner of the television receiver is responsible

17. What formula shows how voltage, current and
resistance relate to each other in an electric circuit?

A. Ohm's Law
B. Kirchhoff's Law
C. Ampere's Law
D. Tesla's Law

18. In what direction does a vertical antenna send out
radio energy?

A. Most of it goes in two opposite directions
B. Most of it goes high into the air
C. Most of it goes equally in all horizontal directions
D. Most of it goes in one direction

19. What item of test equipment contains
horizontal- and vertical-channel amplifiers?

A. An ohmmeter
B. A signal generator
C. An ammeter
D. An oscilloscope

20. What determines the free-space polarization of an antenna?

A. The orientation of its magnetic field (H Field)
B. The orientation of its free-space characteristic impedance
C. The orientation of its electric field (E Field)
D. Its elevation pattern

Adopted from e-ham question bank

Saturday, October 08, 2005

2nd Radio Amateur Examination for 2005

This serves to remind all potential candidates for the above
event, that the next RAE will be held on the:

29 November 2005 at 2pm

MCMC news item link below:

Application Form for the exam is at:

MARES fees for the RAE Course will be RM60.00,
so get the books out, heads cracking, and get the application forms sent in ASAP..

Closing date is 22 October 2005 for all applicants to send in their Forms to MCMC.

Thursday, October 06, 2005

For Sale

The Radio For Sale has been withdrawn.

Wednesday, October 05, 2005


Since the response for us to conduct the RAE classes
has been poor, those that need to get some revision
done can do so by attending classes organised by MARES.
Email below email was received from Lokmal 9M2CIA of MARES.


Mares will conduct another RAE Class on the 15-16 October 2005.

Venue: Dewan Kuliah G,Fakulti Kejuruteraan Mekanikal

For those interested, please submit your entry form which is
downloadable from and return to
Lokmal at or call 0196781631.
Those attending these revision classes will be charged RM40.00.
First timers will be charged RM60.00. Participation will be based
on first come first serve basis, so please submit earliest possible.