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Saturday, April 30, 2011

9M2RDX, 9M2BAL AND 9M2PJU QSO ON 40M



Kenwood TS-570D with GR5V Junior antenna (40m half wavelength) 30 feets above the ground. 70 watts power transmission to Temerloh (9M2RDX) and Kuala Terengganu (9M2BAL).

Wednesday, April 27, 2011

How To Use MFJ-945E Mobile Tuner



Using the MFJ-945E:

The INDUCTOR switch on the MFJ-945E represents maximum inductance at position A and a
minimum inductance at position L. Less inductance is needed at higher frequencies than at low
frequencies for the same impedance. The TRANSMITTER and ANTENNA controls both
represent maximum capacitance at position 10. For optimum operation of the MFJ-945E, the
transmitter must be tuned to a 50 Ohm output impedance at the operating frequency.  

Always tune the transmitter at a low output power! 

Do not readjust the transmitter loading control setting after loading it to a 50 Ohm load! After properly tuning the transmitter, tune the MFJ-945E for a minimum SWR as described below:

When using the MFJ-945E for receiving only, tune as described in Steps 1 and 2.

1. Set the TRANSMITTER and ANTENNA controls to position 5. The tuning capacitors are half opened at this setting.

2. Rotate the INDUCTOR control until maximum noise is obtained with your tranceiver in the receiving mode.

WARNING: Never transmit while changing the INDUCTOR setting!

3. While transmitting a steady state carrier (CW), alternately adjust the ANTENNA and TRANSMITTER controls for minimum SWR. Since both of these controls interact, the two controls can best be adjusted by turning the TRANSMITTER control a small increment at a time, then rotating the ANTENNA control for minimum SWR. Repeat this procedure until minimum SWR is obtained.

4. If an SWR of 1:1 is not obtained, increase or decrease the INDUCTOR control and repeat Step 3. If arcing should occur between the capacitor plates, increase or decrease the INDUCTOR control one position, then repeat Step 3. NOTE: If you can't obtain a 1:1 SWR, repeat Step 3 for each INDUCTOR control position.

5. After minimum SWR is achieved, transmitter power may be increased up to 300 Watts. Your MFJ-945E will reduce the SWR of most feed systems to 1:1. In some cases, a 1:1 SWR is not possible. Increase or decrease the length of your antenna to improve SWR.

6. An SWR of 1:1 may occur at more than one set of control settings on your MFJ-945E. When an SWR of 1:1 is obtained, check transmitter power. Ensure that transmitter power is relatively high. If transmitter power has decreased substantially, try another INDUCTOR control setting and repeat Step 3.



Monday, April 25, 2011

9M2PJU QRP Operation With Yaesu FT-817




My QRP operation on 40m with Yaesu FT-817 using dipole antenna. Contacted stations are 9M2ZC mobile, 9M2BAL, 9M2AGC, 9M2AR, 9M2YRS, 9M2AGC and 9M2VOT. Thanks for the report folks!

Saturday, April 23, 2011

CQ CQ CQ DE 9M2PJU AR


9M2PJU's on QRZ.com, HamCall.net.



ITU Prefix For Malaysia

9MA-9MZ

  1.  9M0 Spratly Is (ITU Zone 50 CQ Zone 26)
  2.  9M2 West Malaysia (ITU Zone 54 CQ Zone 28) [lat 3.2 long 101.6] {start 9/16/63}
  3.  9M4 West Malaysia (ITU Zone 54 CQ Zone 28)
  4.  9M6 East Malaysia (ITU Zone 54 CQ Zone 28) {lat 5.8 long 118.1] (start 9/16/63}
  5.  9M8 East Malaysia (ITU Zone 54 CQ Zone 28)


9WA-9WZ

  1. 9W West/East Malaysia (ITU Zone 54 CQ Zone 28)


Sunday, April 17, 2011

World Amateur Radio Day



Each year on 18 April, radio amateurs celebrate World Amateur Radio Day. On that day in 1925 the International Amateur Radio Union (IARU) was founded. In 2010, the theme of the event is "Amateur Radio: Combining communication experience with modern digital techniques."

Amateur radio has truly entered the 21st Century. In less than 100 years amateur radio communications has evolved from crude spark-gap technology to digital signal processing and software-defined radios. The amateur's HF choice between voice and CW has been expanded to a broad range of communication choices from television to spread spectrum.

Amateur digital communications has evolved. At the end of World War II until the early 1980's, radioteletype, also known as RTTY, was the only HF digital mode available to amateurs. In the 1980's, AMTOR made its debut along with the increased popularity and availability of personal computers. AMTOR was the first amateur digital communication mode to offer error-free text transmission.

From the early 1980's, the rate of change increased dramatically. Packet Radio emerged and for a period of time was the most popular form of amateur digital communication. As microprocessor technology became more sophisticated, there was a rise in modes such as Clover, PACTOR, and G-TOR that were capable of error-free exchanges under marginal band conditions. In the late 1990's, there was an invention that harnessed personal computer technology to create PSK31.

In the VHF-UHF frequency ranges, Packet Radio had less activity at the close of the century than it did in the 1980's and 1990's. However, Packet Radio was reborn as the popular Automatic Packet Reporting System (APRS) and traditional packet systems still exist to support public service activities with greatly enhanced functionality.

Thanks to individual amateurs, hams now enjoy digital meteor scatter contacts and even moonbounce on VHF and UHF frequencies with modest stations. An ordinary computer sound device and software that can be downloaded free from the internet is all that is needed.

The Japan Amateur Radio League developed the D-STAR digital voice and data standard and there has been significant amateur growth as amateurs establish D-STAR repeater networks on the VHF, UHF and microwave bands.

All of these development have inspired amateurs around the world to experiment in their own HF, VHF, UHF and microwave band digital communication.
Activities on the occasion of World Amateur Radio Day 2011 can be a great opportunity to spread the word about what the "hams" are doing in the 21st Century.

Saturday, April 16, 2011

QRP 900 GRAMS HYDRAULIC TUNED SMALL MAGNETIC LOOP

My name is Alexandre Grimberg, my call sign is PY1AHD. I have born in Rio de Janeiro in 1949.I receive the PY1XLS call sign on the year 1978, and in 1987 I became “Classe A” with the call sign PY1AHD.I am a lawyer working on the security electronics business since 1974 on my own company called Radiocom (www.radiocom.com.br). I remember when I was young boy that while all my friends was playing football I was at home developing all kind of scientific experiments. Today after 50 years I am still developing my own toys.
For the last four years I am designing and field testing small magnetic loop antennas for QRP HF back pack operation and the loops became my FT817 best friends.


The first step to build a magnetic loop is to find out a variable capacitor. If you have a 50 Pico Farads maximum and a 10 Pico Farads or lower minimum capacitance split or butterfly capacitor in your hand, you just have the passport to the amazing small magnetic loop world.The small magnetic loop described on the text can tune by the home made 5 Pico Farads to 50 Pico Farads variable capacitor any frequency between 10 meters to 20 meters, and with the parallel association of a 180 Pico Farads capacitor it covers the 40 meters band. Working QRP (less then 10 watts) allows me to design some very interesting variable capacitors from metal tubes (piston type) to sliding capacitors made on printed circuit boards.If you want to run 100 watts of power you can look for a big plate spacing split, butterfly or the high isolation vacuum type capacitors. High isolation capacitors are expensive, big, heavie and hard to find.If you design a 100 watts loop you will need to know the risks that the RF exposure generated by the high concentration of RF energy on the loop. So is recommended keep at least 15 meters distance from the loop.


What is a magnetic loop antenna?


Threre is a quantity of written information about the small magnetic loop antenna. I will try to explain to the newcomer in simple words how it works.


1) Think on the loop as an RF transformer. The primary, the excited loop is 1/5 of the main loop. It is constructed with any kind of self supported wire (can be thick copper wire, coaxial cable shorting the braid with the inner wire, etc...). The secondary, the main loop is the conductor circle closed by the variable tuning capacitor that irradiates the radio frequency energy. Remember that there is no electrical contact between the excited loop and the outer loop.
2) The magnetic loop antenna is a high “Q” device. The band width is narrow and the user is constantly requested to retune the antenna for the lowest SWR transmission any time there is a frequency changing.
3) The high “Q” of the magnetic loop works like a front end tuned filter circuit. It acts as a pre selector greatly improving the adjacent channels rejection.
4) The small magnetic loop can be used on the vertical plane or on horizontal plane. When you turn the loop on the vertical plane you can kill sources of electrical noise and other kind of interferences.
5) The small magnetic loop works perfectly at low heights, normally a 1 meter diameter loop works perfectly only at 1 meter above the soil.
6) And the last and most important advantages of the small magnetic loop:
NO COUNTERPOISES.


This antenna was presented to CQ Magazine readers by Dave Ingram K4TWJ on his World of Ideas column on the October 2006 issue and translated to Spanish to the December 2006 issue of Radio CQ Magazine.The antenna including the control serynger, the cable and the connector have a total weight of 900 grams, and when I have the adjusting serynger on the acrylic support on my belt results on a weight 200 grams lower.
In practice I have only 700 grams of antenna on my back pack.


..
..
..
Antenna weight
Excited loop
The excited loop is 1/5 of the main loop size. It is constructed with any kind of self supported wire, can be thick copper wire, coaxial cable shorting the braid with the inner wire, etc... 


Water tuned sliding variable capacitor
To make the sliding variable capacitor I cut two printed circuit board rectangles. The fixed one measure 180 milimetrs by 58 millimeters and the sliding one measure 58 millimeters by 70 millimeters. Do not forget a 10 milimetrs by 10 millimeters extension on the lower right side to of the sliding printed circuit board that will accommodate a slot to solder the coaxial loop braid.

..
The copper over the fixed printed circuit board is over half of the board.It is important to cut a small rectangle measuring 2, 9 centimeters by 2 centimeters on the right top of the fixed plate to keep enough room for the right side of the loop conductor (coaxial cable).
The size of the coaxial braid from the end of the loop to the sliding plate slot is 250 millimeters.The coaxial loop cable extremes are fixed in place by three plastic ties on each side on the main base.

.
On each side of the fixed capacitor plate I have carefully glued with cyanocrilate (Super Bond) two pieces on plastic” U” channel guides.

This guide is made for the hobby and modeling market in California by Plastruct by the reference “90583”.The fixed rectangle capacitor plate is glued to the acrylic base by double faced Scotch tape.The acrylic base measures 26 centimeters on each side, 9 centimeters on the top and 5 centimeters on the smaller side.
The antenna “boom”

The antenna “boom” is made on a one inch diameter water plastic pipe. The tube is 1 meter long and the serynger fits with little pressure inside of the tube inner wall.




..
I developed a hydraulic system that can control the moving plate position resulting on a variation on the resonating frequency of the antenna between 14 megahertz to 30 megahertz. 

..
The seryringer is a 20 millimeters type and the excursion is 7 centimeters.I have made a “U” shaped acrylic support transpased on my belt trousers that keeps in place the frequency calibrated 20 milliliters serynger that permits tune the antenna atached on my backpack.

..
40 meters adaptor
A 180 Pico Farads fixed capacitor is connected to an alligator clip and lowers the resonating frequency of the antenna to cover the 40 meters band.

.. ..
Keep in mind that working on 40 meters with this antenna we can expect only
4% efficiency compared to a 40 meters dipole, but despite of this supposed low efficiency be prepared for great surprises 
Making the loop
The loop is made on RF 52 ohms coaxial cable. The coaxial cable reference that I use on this type of loops is the RGC-213. This cable have a 0,25 centimeters diameter inner copper wire that will keep the magnetic loop self supported on a perfect circle shape.The total extension of the loop circle is 254 centimeters, resulting on a circle of approximately 80 centimeters in diameter.The coaxial loop cable is short circuited soldering the braid to the inner copper wire.
On the left coaxial loop extreme leave 1 centimeter of the inner copper wire involved by the braid and make a good solder using a clean 100 watts soldering iron.On the right coaxial loop extreme leave 1 centimeter of the inner copper wire soldered to the braid.On this side you must leave 25 centimeters of braid on a semi circle shape to be soldered on the slot of the moving printed circuit board sliding plate.These 25 centimeters of braid will allow the free movement of the capacitor sliding upper plate.


Water tuned loop schematics

..
What is the efficiency of this QRP magnetic loop?
According on G4FGQ Reg Edwards software:
Band
Efficiency
Loss in db (ideal antenna)
S-Units
10
12
15
17
20
40
90.7%
84.5%
73.43%
60.50%
37.80%
4.6%
0.4 db
0.7 db
1.3 db
2.2 db
4.2 db
13.3 db
0.1
0.1
0.2
0.4
0.7
2.2
I hope that with this project I can stimulate the imagination of the radio amateurs all over the world.I would like to say that I have more then 500 Dxs over the last four years with a FT817 and one of my loops and many of them with other hfpack stations.One of the most interesting was a pedestrian mobile to pedestrian mobile QSO with G0SBW Tom in England on 17 meters band registered on the Hall of Fame of the HFpack group as a world distance record on this category.Another one that impressed me takes place when I was walking on the sand of the paradisiacal beach of Coroa Vermelha in Bahia with the 817 and my Traveling Loop when I reach VR2XMT Charlie in Hong Kong returning to my call with a 5 by 9 signal report.

e-mail: py1ahd@ig.com.br

p:/s tribute to Mr. Alex PY1AHD. My magnetic loop antenna tutor. http://alexloop.com/ 

 

9M2SX's 40m-20m Magnetic Loop Antenna


Having Space Constraint At Your QTH To Put Up An Antenna For HF Band?.
Then Try Constructing This Magnetic Loop Antenna.

 
Dwelling on the 7th floor of a 12-storey flats means that space constraint was the major problem for me. Then the challenging task of using a suitable antenna for HF band arises when I got my amateur radio operating licence. Using a dipole antenna or beam antenna is out of the question because the building management does not allow me so. For those of you who are able to do so, consider yourself very lucky indeed.

I have tried using a dipole antenna and a windom antenna that was hooked up in such a way that the antenna wires did cover nearly the entire ceiling of my QTH which was also the floor of my neighbour above.

Lucky for me, my xyl is supportive towards my hobby and could bear the madness in me trying to communicate with the world out there via amateur radio. My dipole antenna and windom antenna that was hooked up to the ceiling, did not perform as it should in the open space. Anyway, I did manage to have a few local contacts with very discouraging signal reports. So what else can I do?, back to the drawing board.

Articles about the magnetic loop antenna have appeared from time to time in many amateur radio magazines, With these relevent articles in hand, I experimented with few variations of the magnetic loop antenna and never stop trying to improve the magnetic loop antenna’s performance since day one.

The magnetic loop antenna is a small circular antenna that can operate on multi-band like 40m to 20m, 20m to 10m, and even tri-band, 40m to 15m. I was able to construct a tri-band magnetic loop antenna few years ago and worked many DX stations with it before the capacitor’s rotor contact was giving me hell of a problem. The bands that the antenna will be covering depend on the type of variable wide-spaced capacitor that you use. A split-stator type is recommended, but I have been using the normal type and it works just fine (see photograph).

I do not have an antenna analyzing equipment to work with. Just using my old trustworthy Oskerblock SWR-200 s.w.r. meter, a home made noise bridge and a passive field strength meter to do the testing.

I started building my first on December 1988. First time on-air using the magnetic loop was on January 8, 1989 at 7.040MHz with several 9M2 stations. Encouraging signal reports and comments was received. This paves the way for improving my magnetic loop antenna. My first DX contact on 20m, using my improved version of the magnetic loop antenna, was with UC1 station on February 5, 1989. With good signal report received, I smiled ear to ear.

The Construction


My prototype of the magnetic loop antenna was made from a 3/8-inch diameter copper tubing. It is best that you start first with a small diameter copper tube for the loop and then progress to a larger diameter later
on. This will help you to understand more about the characteristic/performance of the magnetic loop antenna. About 11 feet in length of the copper tube was required to make a 37-inch diameter loop element. The 3/8-inch diameter copper tubing (used for air-conditioning systems) is quite soft and I was able to bend it slowly by hand to the form a loop and trim of the extra length if necessary, taking into account the 1 inch gap at both ends of the loop (see illustration).

 
My later version is made from 1 inch diameter copper tubing. The antenna’s efficiency seems to be better but the bandwith is narrower at resonant frequency with larger diameter copper tubing. I used the services of a local metalworking workshop to bend the copper tubing into a loop. The whole loop was then mounted onto a 1-inch by 1-inch square aluminium tubing support of suitable length. The aluminium support must be isolated from the loop by means of an insulator. In my design, I used 2 pieces of 1/2 inch thick rectangular ceramic plate with ready made holes in it. I got this stuff from the local junkyard.


The insulator must be placed between the loop and the support. Please take note that from my experiments and experiences, using a metallic support for the loop have very little effect on the overall performance of the antenna provided the support is well insulated from the loop. In my setup, the support is mounted on an antenna rotator. This setup allow me to swing my antenna system in (when not in use) and out (when in use) of my QTH’s balcony, also to point towards certain direction or countries.


The Tuning Capacitor


This is the only critical component of the whole project. The magnetic loop is a tuned loop and is a very high Q circuit. High RF voltages appears across the capacitor vanes. An excess of 1000 volts may appear between the plates with an output power of 100 watts RF. That is why a wide-space capacitor is required. The type of variable capacitor that is available in the old broadcast receivers will flash over with about 25 watts output of RF power. Unless you decided to go QRP, then you can use this type.

 
The capacitor that I am using was salvaged from an old HF linear amplifier hidden away in a corner at the local junkyard. The wide-spaced capacitor has a maximum value of 250pF and 5kvdc working voltage (see photograph). This is ideal for 40m to 20m operations including 30m. The stator of the capacitor is connected/soldered to one end of the loop, while the rotor is connected/soldered to the other end using heavy gauge wires (see illustration). To vary the capacitance of the capacitor, that is to tune the antenna to the resonant frequency, I connect it to a 1 rpm 110vac small electric motor via a 5:1 reduction drive. The motor is powered from my shack through a home made rotation control to turn the motor spindle clockwise or counter-clockwise direction. This method allows me to vary the capacitance of the tuning capacitor.
With this setup, I can remotely tune the antenna from my shack. You can do without the remote tuning system if you wish, but then it will be necessarily for you to ply to and from your shack to the antenna in order to manually tune your antenna. If you opted for this, then remember to use an insulating spindle/knob attached to the capacitor. The whole assembly comprising of the capacitor, reduction drive and electric motor is placed in a 4-inch diameter PVC tube housing using suitable bolts and nuts.

Both ends of the PVC tubing is sealed as to make it weatherproof. Only the wires connecting the capacitor to the loop and power supply wires to the motor protrude out of the housing. The pvc housing assembly is then fastened to the aluminium support and make sure that the capacitor is not in contact with the support. The reduction drive and the motor is isolated from the capacitor by means of an insulating flexible coupling salvaged from an old radio.







The Gamma Match For Antenna Feeding/Matching System

Here I prefer the gamma match system over the small inductive coupling loop system as it is much easier to build and less critical to setup. Using a 22 inches long, 1/4-inch diameter copper tubing, I bent it to form a semi-circle. One end of the gamma match is connected to the center conductor of the RG-58 co-ax cable. Please make sure that this portion is not in contact with the loop and weatherproof it. The other end of the gamma match is temporarily connected/soldered to about 10 inches away from the mid-point of the circumference of the loop from the open end. The braiding of the co-ax cable is connected/soldered to the mid-point of the loop (see illustration). Please bear in mind that you need sufficient length of co-axial cable from the intended location of your antenna to your transceiver before connecting your feeder cable. I used a 100w electric soldering iron for the required job and good clean soldering contact is a must to avoid RF losses to the antenna setup.
 

 
Tuning and operation

With all connections properly done and antenna placed many feet away from you or others, switch on your transceiver in receive mode, the range of bands covered by your loop antenna. Select a desired frequency, e.g. 7.040Mhz, listen for band noise/signal. Now rotate/adjust slowly the capacitor until there a sharp rise in the noise/signal. Tune for maximum. At this point, it is said that the antenna is at resonance. With a SWR meter in circuit, apply a very small RF power to the antenna, about 5-10 watts, and note down the swr reading. Select another frequency, e.g. 14.200Mhz, and repeat the procedure as for 7.040Mhz. You will have two different sets of swr readings for the two frequencies.

Switch off your rig and disconnect the co-ax at your rig. This is for safety measure because soldering/unsoldering work done at the antenna end while using an electrical soldering can damage your rig if there is electrical power leakage. So don’t take chances!. Unsolder the end of the gamma match that was temporarily soldered to the loop earlier. Bend the gamma match slightly as required and resolder at about ¼ inch up or down from the original spot.


Proceed with the tuning procedure as before and noting down the swr readings. Repeat as necessary until you get a minimum swr reading for both bands or frequencies. Adjustment is very critical because of the antenna’s high “Q” and narrow bandwidth. After all is done and you are confident about it, then you can transmit with more power if you desire. Do not use an A.T.U. with this antenna. Please remember that the direction of maximum radiation from a magnetic loop antenna is in the plane of the loop antenna and not the broadside of the antenna.


Results From Using This Antenna

Please take note that I was unable to refer to any other fellow amateur radio operators in 9M2-land with matters pertaining to the construction and use of this antenna because at that time no other amateur radio operators here (9M2-land) was using this type of antenna way back in the late eighties. I was on my own.

Good signal reports and favorable comments was received while having QSOs with local and DX stations. My favorite band for DX operation is 20m and sometimes I shall be having a pile-up.

Here are some station prefixes of many confirmed DX contacts using my magnetic loop antenna.
On 40m:
IK4, HA0, ZS6.

On 20m:
8J1, VQ9, LX2, JT1, VO1, S09, XZ1, XX9, 9H3, EA8, 9N1, 5N7,
EI2, 9X5, GI0, 9A2, SM0, OH8, LA7, OZ1, PT7, OM9, M100G.

On 15m with my tri-band version mentioned in my text:
EA9, 9A2, F5D, OZ7, HB9, OH2, DL2, OK2



My purpose in writing this article is to show that even a small size antenna like my home made magnetic loop antenna can perform well provided that you put in much effort into the project. Please take note that I constructed and use this antenna out of necessity and I have no regrets about it.

More reading on this subject has to be done if you wish to improve this antenna. My construction literature provided here is based upon my experimentations and I am unable to provide any mathematical calculations/data to prove the efficiency of the antenna design because it is from a layman and that’s me, who knows very little about mathematics.

Here are some of the QSL cards that I have received.
 

 

Happy DXing

All the best and 73.

Saito 9M2SX
Penang Island (IOTA AS015)
Malaysia










9M2SX's Grounding Wire Using Coaxial Cable With Capasitor

HF TRANSCEIVER GROUND (EARTH) WIRE USING CO-AXIAL CABLE.


      Living in a flat has it’s own problem where radio frequency (RF) grounding for a HF transceiver is concerned. Improper grounding/earthing system can cause several unwanted RF interferences (RFI) to television sets, broadcast receivers, hi-fi sets and telephone sets.
I have these RFI’s when using my transceiver on 40m, 20m, and 15m. I have not tried using 10m because my home made magnetic loop antenna was unable to operate on that frequency.  By the way, my ground wire is connected to the 4-inch diameter cast iron sewage piping system about 35 feet away.


     With the assistance from my XYL, who is quite familiar with the operation  of a HF transceiver, I started my troubleshooting for the source of RFI’s.   Using the multi-function ‘Dinky’ SWR meter model SS-51 by Oskerblock, I switched to field strength meter (FSM) function.  While my XYL was keying-up the transceiver at preset intervals with 30 watts on a clear 40m frequency, I adjusted the sensitivity of the FSM for minimum deflection. This is because I do not want to be confused with the RF picked up from my home made magnetic loop antenna that is mounted at the balcony of my flat.


     After all the necessary adjustments made, I started moving the FSM close to all wires laid out from the shack including the ground/earth wire. To my surprise, the needle of the FSM was deflecting strongly when I brought the FSM close to about 3 to 4 inches from the insulated ground/earth wire that was connected to the sewage pipe. As I moved the FSM along the wire, there was strong deflections. No meter deflections was recorded near the sewage pipe. This means that my ground/earth wire is radiating some how!. It was the same on 20m and 15m.  Labouring with my thoughts, how am I going to solve this problem?. Using a low pass filter does not solve this either. I need a method to shield the ground/earth conductor wire that is something like my antenna feeder cable.


     With a sufficient length of RG-58 co-ax cable in hand, I connect the center conductor with one end to the transceiver’s ground and the other end to the sewage pipe.  This leaves the co-ax brading ‘floating’. I thought that the braiding can act as a shield. After keying-up the transceiver, the RFI problem persist!. After reading through some articles about RC and LC circuits, I soldered at both ends a 470pF 1KV ceramic disc capacitor (C1, C2) across the center conductor and braiding of the co-axial cable. Please refer to the diagram below.



 


     When the transceiver was keyed up by my XYL, I noticed that the FSM meter deflection was only about one third compared to earlier deflections. This shows that the co-axial cable braiding is partially shielding the center conductor!. Traces of RFI’s to my television set, broadcast receiver, hi-fi set and telephone set was now non-existent. Then I decided to replace C1 and C2 with value of 820pF 1KV.   Builders can try different capacitor values.  Further tests show that the FSM meter deflection was minute or no deflection at all even at maximum sensitivity.

     The co-axial cable braiding now acts as an extremely effectve shield and any RF that reaches and absorbed by the braiding will be transfered or bled back to the center conductor via the capacitors.  This is because the path of lowest resistance is through the center conductor.

     I have been using this co-axial cable ground wire system since the middle of 1989 and no RFI’s has been encountered in my QTH or received complaints of RFI’s from my neighbours.

     If you have RFI’s possibly due to your grounding system, then experiment with this system.  It might help you.  So please give it a try.  Thank you.




73 and all the best,

Saito 9M2SX
Penang Island ( IOTA AS015 )
Malaysia

Thursday, April 14, 2011

United States amateur radio callsigns

Search any United States amateur radio callsigns here at http://wireless2.fcc.gov/UlsApp/UlsSearch/searchLicense.jsp for full information including name, status, grant and expiry dates, previous callsigns and operator class. For Malaysia amateur radio callsigns, please go to http://www.skmm.gov.my/link_file/registers1/aa.asp?aa=AARadio

Specialized Interests and modes In Amateur Radio




While many hams simply enjoy talking to friends, others pursue a wide variety of specialized interests.

* Amateur Radio Direction Finding, also known as "Fox hunting"
* Amateur radio emergency communications
* Amateur television
* Communicating via amateur satellites
* Contesting, earning awards, and collecting QSL cards
* Designing new antennas
* DX communication to far away countries
* DX-peditions
* Hamfests, club meetings and swap meets
* Hand building homebrew amateur radio gear
* High speed multimedia
* High Speed Telegraphy
* Packet radio
* Portable, fixed, mobile and handheld operation
* Low-power operation (QRP).
* Severe weather spotting
* Tracking tactical information using the Automatic Packet Reporting System (APRS), which may integrate with the GPS
* Using the Internet Radio Linking Project (IRLP) to connect radio repeaters via the Internet
* VHF, UHF and microwave operation on amateur radio high bands
* Vintage amateur radios, such as those using vacuum tube technology
* Morse code, amateur radio VOIP, satellites communication and tracking, and many more!

Sunday, April 10, 2011

HF NVIS Magnetic Loop Mobile Antenna









http://en.wikipedia.org/wiki/Near_Vertical_Incidence_Skywave

Saturday, April 9, 2011

Cara Menguasai Kod Morse

Kaedah Koch

Secara tradisional, kod Morse diajar dengan cara susah dengan cara menerima semua kod pada kelajuan perlahan dan kemudian maju ke kelajuan yang lebih tinggi.

kaedah Koch, iaitu cara lain membuktikan bahawa anda harus mulai belajar dengan kelajuan yang dikehendaki - tetapi anda bermula dengan hanya 2 karakter yang dihantar secara rawak. Setiap sesi adalah lima minit, dan setiap kali anda mendapatkan 90% atau 100% betul, anda boleh menambah hanya 1 karakter lain. Kombinasi Koch adalah seperti berikut K M U R E S N A P T L W I J Z F O Y V G Q H B C D X. Untuk nombor pula, 1 2 3 4 5 6 7 8 9 0. Kombinasi sebenar Koch adalah terdiri dari gabungan huruf dan nombor, saya telah mengasingkan antara karakter ini bagi memudahkan sesi pembelajaran.

Kaedah Koch dicipta oleh psikologis Jerman Ludwig Koch pada 1930-an.

Pemasaan Farnsworth.

karakter dihantar pada kelajuan yang tinggi, tetapi jarak tambahan dimasukkan di antara aksara dan kata-kata untuk melambatkan kelajuan penghantaran sebenar. Keuntungan dari ini adalah bahawa anda terbiasa untuk mengenali watak pada kelajuan yang lebih tinggi, dan dengan demikian akan lebih mudah untuk meningkatkan kelajuan nanti.

ARRL menggunakan pemasaan Farnsworth untuk penghantaran, latihan dan kaset ujian dengan kelajuan 18 WPM (90 CPM).

Pemasaan Farnsworth dicipta oleh Donald R. Farnsworth (W6TTB) pada akhir 1950-an.

Kaedah Rekaan 9W2PJU (Hehe)

Diambil dari peribahasa "bersusah dahulu bersenang kemudian". Satu kombinasi telah dicipta dengan memulakan latihan dari huruf yang dianggap susah kerana bunyi yang terdiri dari 4 dit atau dah. Apabila anda dapat menguasai huruf yang dianggap susah ini, secara tidak lansung huruf yang terdiri dari 2 dit atau dah, 3 dit atau dah akan menjadi lebih senang.
Pemasaan untuk kaedah ini sama seperti Koch, jika sasaran anda untuk mencapai kelajuan 12WPM, cadangan kelajuan adalah 14 ke 15WPM bergantung kepada kesusaian diri. Jika termampu, teruskan bermula dari 18WPM. Tidak menjadi masalah untuk bermula dari kelajuan yang tinggi kerana anda tidak akan selamanya ingin bekerja pada kelajuan 12WPM.
Kombinasi adalah FL QY BV PX CZ JH DG KR OS WU MI NA TE.  Setiap sesi adalah 10 ke 15 minit, bermula dengan 2 huruf dihantar secara rawak dan setiap kali anda mencapai 90% atau 100% betul, anda boleh menambah 2 huruf yang lain. Jangan tambah sebarang huruf jika anda masih ragu-ragu. Jika anda berjaya menyalin dari FL QY BV PX CZ JH, nescaya huruf DG KR OS WU MI NA TE akan menjadi senang.

Teknik Pengasingan Dit Dan Dah.

Teknik ini mengasingkan antara bunyi dit dan dah. Bermula dengan huruf E I S H , T M O, dan seterusnya seperti aliran dalam carta ini



Kelajuan yang disarankan adalah seperti pemasaan Farnsworth. Kaedah ini sesuai untuk mereka yang "tone deaf". Ini adalah kerana bunyi antara dit dan dah telah diasingkan supaya mereka lebih senang untuk membezakan antara bunyi tersebut.

Software yang dicadangkan boleh didapati di http://www.justlearnmorsecode.com/
Ini adalah kerana software Justlearnmorsecode ini sangat ramah pengguna, tone dan kelajuan boleh diubah mengikuti citarasa, kombinasi yang boleh diubah mengikut pelbagai kaedah serta pattern penghantaran yang menyerupai ayat sebenar.

p/s: perlu diingat bahawa kod Morse adalah kod bunyi. sebarang cara untuk mengingati kod secara Visual Mnemonic adalah cara yang salah sama sekali, kecuali dengan cara Syllabic Mnemonics. setakat ini masih tiada dokumen tentang Syllabic Mnemonics kod morse yang sesuai dalam bahasa Melayu, kecuali dalam bahasa Inggeris. sila rujuk http://en.wikipedia.org/wiki/Morse_code_mnemonics . Jangan belajar dalam keadaan yang selesa, jangan biasakan dengan 2 spacing, cuba 12WPM, 13WPM atau 14wpm single spacing dan paksa diri anda sampai ke kemuncak. Latihan Kod Morse adalah untuk membina reflek di dalam minda, bukan formula ataupun teknik mengira berapa dit atau dah. Biasakan dengan irama sesuatu huruf. Jika tonenya tinggi, mungkin kod itu akan berbunyi seperti "tit ta, ta ti ti ti", jika tone itu sedang-sedang, morse akan berbunyi seperti "dit da, da dit dit dit, dan juga jika tone terlalu rendah, mungkin akan berbunyi seperti, "bi ba, ba bi bi bi", oleh itu jangan bertanggapan bahawa Kod Morse itu akan berbunyi sempurna, cuba biasakan dengan perbagai tone bunyi dan kelajuan. Sebagai latihan, jika anda melihat sesuatu huruf, biasakan dengan menyanyikan irama huruf itu di dalam hati. Sebagai permulaan, cubalah satu huruf sehari, dengar sambil salin di kertas. Mendengar tanpa menulis huruf adalah sia-sia bagi mereka yang baru berjinak dengan Kod Morse.




Sesungguhnya tiada satupun kaedah yang boleh menjanjikan penguasaan anda dalam Kod Morse jika anda sendiri tidak berusaha. Latarbelakang seseorang adalah berbeza dari segi IQ, jantina, umur, pendidikan, pekerjaan, bakat, kesungguhan dan lain-lain. Anda harus mencuba pelbagai kaedah dan bereksperimentasi dengannya supaya anda temui teknik yang paling sesuai bagi diri anda.

 
"Practice makes perfect"
"Alah bisa tegal biasa"

Selamat mencuba.

Friday, April 1, 2011

Malaysian Amateur Radio Callsigns

Here is the list of Malaysian Amateur Radio Callsign. Harvested from MCMC's website by 9M2CIO. The purpose of this file is to help public to search for the callsign while on the move and surely offline searching. You can save this file to your mobile phones or portable computers and open it anytime you like.

Download URL: http://dl.dropbox.com/u/8414601/amateur%20radio/callsigns.pdf
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